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A special scope designed for US shooters II

5/27/2015

2 Comments

 
Between the EMails, Comments and Posts about our previous entry, it is clear that part of the confusion comes from an oversimplification of the internals of a riflescope.

My good friend Brian Samson has posted that he thinks using this scope at 12X for the UK version of the 'Hunter FT' game would be a "terrible" idea. He cannot conceive how a 56 mm's objective lens with a 12x magnification can have any depth of field.

I have another good friend that says that one small, concrete, solid, real, test is worth 100 "expert" opinions. He usually refers to me when he says that, so I do not know why he is my friend, ROFL! but he is.

And so, without further ado, let's exemplify in pictures what a professional oriented scope can do:
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This is the test setup. I had to create a device to affix the scope to a tripod. Not bad, I had been wanting to do that for some time, so this test afforded me the reason to do it. Now I can test the scopes before they get sent to their end users ;-) Targets are set 5 yards apart, starting at 10 and going all the way out to 50. This is 5 yards too far for the UKAHFT game, but this is a test ¿right?
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The scope setting in magnification. Perhaps 12X was a little overenthusiastic on my part but, mostly, without a steady holding device, in my shaky FT position (which is banned in UKAHFT, BTW) it was what I had tested previously.
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This is the 50 yards target. Setting the parallax of the scope at 36 yards (the stone ledge seen here), you can clearly see the 50 yard boar and its KZ. And, more importantly, you can still MEASURE it. Granted the KZ's in this test are pristine, unshot. But it is also true that the targets are lit in a peculiar way with some shadow play. Even with the uneven light and the treacherous disposition of the string rings, the whole sight picture is not too much out of focus. Another important aspect is that, as per UKAHFT format, ALL targets have to have white or yellow faceplates with black KZ's. This is a huge boon to the shooter as even when lead splattered, you would still be able to see the black reticle against the pale background of the faceplate itself.
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This is the 45 yards rabbit. Same comments. A little out of focus, but not enough to make it unreadable.
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The 40 yards crow. With some attention you can clearly see the "Remington" logo, the target is perfectly "readable"
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The 35 yards "Wabbit", this is the closest target to the selected range set in the scope (the stone ledge 1 yard behind this rabbit). Perfectly readable, as was expected.
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Now we have the 30 yards crow. Things start to get slightly blurry, but the whole target, as well as its immediate surroundings are perfectly readable.
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The 25 yards boar. Yes the edges are not as defined as they could be, if the scope was perfectly in focus, BUT that is not the name of the game. The name of the game here is to be able to read ALL the targets in the range with a single scope setting. I think that so far, the scope has been performing as it was designed.
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Now we have here the 20 yards boar. Sorry to have put two identical animals in consecutive order, but I think that the picture does show that the target, while not in perfect focus, it is measurable with the reticle.
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A crow at 15 yards. Note how the camera could not decide to focus on the reticle and has now focused on the target. In real life, our eyes will focus in what we WANT them to focus. My tendency would be to focus on the reticle. JMHO
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And now, a 10 yards bunny with the smallest KZ in the Remington set (about 19 mm's). This time the camera decided to focus on the reticle (as our eyes would have in a natural environment)
As you can see from all the pictures above, the scope does a more than creditable job for an entry level priced scope. The "depth of field" can easily be adjusted to span the 15 to 50 yards targets (5 yards MORE than required as per  UKAHFT format. Some SMALL gain could be achieved setting a nearer range, but the objective of this test was only to determine the applicability of this scope to varied shooting conditions and usefulness for a specific purpose.


Now, Brian also comments that a 10X32 would be a better choice to shoot the UKAHFT game. Well, again, let's do a test:
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This is a Tac-Vector Gladiator scope. A 2-12X32 FFP scope set at 10X. This is the Boar at 50 yards. Maybe too far for 10X.
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The 45 yards bunny. Hmmmmm, not too much to measure, nor to have any real info about at 10X with a standard mrad reticle.
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The 40 yards Crow. A hard shot, still.
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The 35 yards bunny. Now, we're cooking! Not easy, but doable. Still, a much handicapped shot in relation to using the ADE scope.
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The 30 yards crow.
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The 25 yards boar.
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The 20 yards boar.
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The 15 yards crow. Again the camera did not really know where to focus.
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The 10 yard bunny.
As you can see, range for range, the 5-25X56 MH FFP scope performs better than the 2-12X32 MD FFP scope.

This begs the question: ¿HOW can this be?

As Brian, we ALL know that larger objective lenses make the system "faster" I.E. it reduces the depth of field. And we are sure that small objectives in a scope HAVE to mean increased depths of field, especially at low magnifications. And yet, here we are, pitting a 56 mm's scope set at ALMOST 12X, vs. a 32 mm's scope set at 10X and still, the depth of field is clearly greater / better in the large scope than in the small scope.

¿How do we reconcile THEORY with REALITY?

Well, truth be told, there is NOTHING to reconcile. If you go to my Blog entry titled "How to Understand Riflescopes" you can read the following:

"In order to provide crispness to the image, scope manufacturers insert a "stop" (a metal plate with a hole) at this point. This reduces the stray light bouncing around the internals of the scope and allows the eye to perceive a "crisp" sight picture. It does not diminish light throughput because the image is already a reduced one and it already includes the reticle." 


Well, ¿what is crispness of image if not another way of describing "in focus"?


The scope designer has not only lenses to play with, but he can also play with "nothingnesses" (if I may invent a word). Judicious use of the stops, either physical or virtual, is what makes this apparent contradiction possible.

The other objection raised is that even if the scope was in relative focus, there would be parallax, and the aiming error introduced through the parallax error is a detrimental thing.
Well, Yes! But that would be true of ANY scope in ANY setting.
Parallax error under these conditions and restrictions needs to be managed by the shooter pro-actively. IMHO, the best way for most shooters to manage parallax error under these conditions is to set the scope as far forwards as the mounts/rail will allow. This creates a "peep within the scope" sight picture that practically eliminates different eye positions. Most shooters will be able to use this technique.

And here I will end up this note saying that there is a HUGE difference between riflescopes made for "sporting" purposes (even if they are $4000 March's and S&B's) and scopes made for "professionals" (meaning those whose lives depend on their tools). When you are designing a scope to be used in a number of different circumstances, conditions and environments, you endeavour to make a versatile scope. As a designer, the use of the stops becomes important precisely when you want to make this versatility COUNT. 


And ¿where would it count more than in the battlefield?


Keep well and shoot straight!












HM
2 Comments

A special scope designed for USA shooters

5/21/2015

10 Comments

 
Among the civilized nations of the earth, the USA is an exception in that it still uses the "Standard Units".
The world, as a whole, has adopted the Metric system; the UK still holds on to some "Imperial" units (slightly larger than the "Standard"), but the US is the remarkable exception that still uses mostly inches for objects' sizing; feet for indoor, and yards for most outdoor dimensions.

Metric angles are usually expressed in "rads" or sub-multiples of them, but Standard angles in shooting are measured in MOA's (Minute of Angle).

Now, the MOA is ALMOST the same as the "IPHY" (Inch Per Hundred Yards), being that 1 MOA is 1.047" @ 100 yards distance; the difference is 4.7%, or 1/20", or, using the smallest commercial pellet caliber as a "sizer", about ¼ of the pellet hole. SO, for airgunners at the usual airgun distances (10 to 100 yards), they can be taken to be the same.

Civilian US shooters resisted for many years the multiple point aiming reticles, and even more the "Christmas Tree" or "Metering" reticle. Shooters claimed the reticles were "too busy".

Well, busy in reality meant that all those extra points had no real meaning in the shooter's mind and were regarded as "useless".


As time has gone by, and more and more ex-servicemen/women return home, the shooting games have evolved, we now have very long range matches. Civilian shooters enjoy the challenge of "mil-dot ranging" and software in portable devices has become sophisticated enough that "Joe Average" can now have firing solutions at his finger tips that up until a few of years ago were the exclusive domain of the professional military sniper.

BUT there was still one important obstacle to be removed. ALL the software, and all the literature makes a big hassle of the maths involved because shooters STILL THINK in terms of inches and yards. Complex formulae are embodied in special purpose slide-rules and apps.

Enter ADE Advanced Optics. A company that MAKES some of the most successful scopes for high end "manufacturers". They have a long standing tradition of scientific instruments making from microscopes to refractometers, astronomical scopes, and a whole host of camera parts.
And they decided to enter the American market with something that spoke the shooter's language. They setup a US office in the NorthWest and are actively looking to serve the US Shooters.

If you go to their EBay store, you can find 485 products, among them 23 Rifle scopes, of which there is one that is the point of this article: the 6-25X56 FFP MOA reticle scope.

Picture
It is not a small scope, but it is not huge either.
Here you can see it mounted in a Diana ZR mount that had to be machined to fit.
Picture
Picture
Why would we machine a ZR mount to fit a scope?
Because the optics are worthwhile and the reticle is an interesting reticle that really needed some precision/FT testing. And we were not going to risk the test by mounting it rigidly to a Diana 54.

Now, a valid question might be: ¿Why would a maker make a scope with a saddle that is almost too big?
For starters, because this maker really knows his stuff. He knows that the bigger saddle allows for beefier parts. Beefier parts mean better survive-ability in the field. In the long run, the shooters are better served.
Yes they may need to buy higher rings (or adapt what they have), but in the long run, it is in the shooter's best interest to have something that will take the bumps of life in the field.

And so, we come to the reticle. Here is a picture at 5X:
Picture
And here one at 25X:
Picture
Interesting, ¿no?

One of the "ailments" of some modern offerings is that the "manufacturer" does not really know what they are making for him in China.

You ask what are the subtensions between hashmarks and they cannot answer properly; some will say they do not know (bad), some will say that "the information is proprietary" (WORSE); ¡What a load of hogwash! 

This annoys me no end. Because, if someone wants to copy that "proprietary" reticle, they only need to get a scope and MEASURE the subtensions. Hiding information from your users is totally useless from the industrial/intellectual property standpoint, and is detrimental to the development of the sports you are supposed to be serving.

Anyway, a BIG advantage of having direct communication with the MAKERS is that at least ONE person in the factory will know what he is doing, and he usually provides pretty good information.
So, for those that are geometrically minded, this is the diagram provided by ADE Advanced Optics:
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Maybe not the clearest of diagrams, but at least some SOLID info here. Let's talk about the diagram first, specifically, the horizontal crosshair of the diagram:
EACH small hashmark is worth 2 MOA
There are 10 MOA's between larger hashmarks that contain 5 X 2 MOA units.
Yes they are the same at any magnification, it is a FFP scope.
If you take the WHOLE horizontal crosshair (you need to be at 15X to see it all), then the whole thing spans 70 MOA's.
The "50 MOA @ 22X" note in the small diagram on the bottom left is not a typo, it actually refers to the scope we are testing but there is no clarification in the diagram, more on that later.

On the vertical crosshair you have finer divisions:
Each small hashmark is worth 1 MOA
Each intermediate hashmark is worth 2 MOA
Each larger hashmark is worth 10 MOA

Now, applying that to our test scope (small diagram in the lower left corner), here is what I would annotate on this particular model:
Picture
I hope that now our test reticle is clear on the subtensions that are marked in the reticle.
Taken outside, the scope is quite clear in its optics, I would say that on par with the better scopes in the price bracket ($200-$300 scopes) and definitely superior to the economy scopes.
On a cloudy and dark/rainy day this is what you see at 35 yards:
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Each board is roughly 2 mrads wide, so if we look at two boards, we see that the reticle tells us they are about 14.4 MOA's. ¿What do we get if we multiply 3.6 X 4? well . . . 14.4. Not bad. Not bad AT ALL! LOL!

The scope itself, has clearly marked knobs. The sidefocus knob indicates the scope capacity to focus down to 10 yards:
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Sidefocus knob turns from 10 to 55 yards in a little less than 180º of rotation, so it is not ideal for FT, but on the other hand for long range hunting, it does have space to rotate out to 300 yards.
Elevation and windage reticles are short and the erector tube is affixed to a bushing, so when you click in either elevation or windage the turrets themselves do NOT move. I would not fear taking this scope out into the rain.
Picture
Remember this scope is NOT for "clickers". This scope is designed to be set to zero and from there on, just use the reticle to make any and all adjustments.
A valid question at this point is ¿how does the scope perform in the field?

Well, I took the scope mounted on my WFTF D54 to the EFTCC shoot of a few weeks ago. Given the small rotation needed to go from 10 to 55 yards, I was under no illusion that it was an ideal FT scope, but at the same time, the fact that some shooters are limited to 12X and at that magnification, pretty much all scopes perform equally bad beyond 35 yards, I thought it was worth a try.
On one peculiar target, it proved invaluable because the focus knob told me the target was much nearer than 10 yards, and being able to dial down the magnification with NO TRAJECTORY AND NO POI CHANGE was calming, soothing, and relaxing. I nailed those two shots, LOL!
The OTHER shots where it was interesting was in the offhand shots. You can take the offhand shots at a lower magnification with less stress and still know that your dope and your POI has not changed. I missed 3 of the 8 offhand shots, but that was not the equipment's fault.

As you have read elsewhere, the shoot ended up being more challenging than expected, and ending up in 3rd place behind excellent shooters like Paul Bishop and Matt Brackett was very satisfying when I had arrived at the range with ABSOLUTELY NO IDEA NOR DOPE.

The PP Calc app, did its job and once I found that the initial sighting in had moved my windage by a full MOA in the wrong direction, I ended up connecting on 7 of the last 8 targets.

"Bracketing" of long targets proved interesting, to say the least from the seated FT position. But knowing some typical dimensions helped a lot.

For those that MAY want to try something like this, here is a chart of apparent object size to distance:
Picture
To use the chart you select the dimension you want to use as a base, USUALLY, the larger the base dimension, the better chance you have at getting a good range. 
Let's say we pick the base of the target at around 7 inches (purple line). And let's say that you measure 14 MOA's for that base. That means that the target in question is, roughly, at 50 yards.
Using another example: let's say that you have a large KZ target in which the MD has been "kind" enough to hide everything but the KZ. And you can measure the KZ at about 4 MOA's; that means that the target can be between 36 and 39 yards. If you know that your pellet's flight changes by about ½" between those two distances, you can still take the shot with reasonable confidence.

If you are a long range hunter, can use Laser Range Finders, or have a good piece of land with known distances, this scope is truly a good scope to have.
If you are a Hunter FT shooter, the scope has a 12X mark and using the bracketing method will give you a good technique to rangefind those targets beyond the 35 yard line.
If you are a UK HFT shooter, the depth of field and the FFP of this scope will undoubtedly put you into the run for the places.

All in all it is a good scope for the money.

Do not expect it to perform like a $1,200 scope because that was never the intent. But within the price bracket and for specific purposes, this might be one of the most unique scopes to enter recently the American market.


Keep well and shoot straight!










HM
10 Comments

The new "Sniper" line by H&N

5/20/2015

10 Comments

 
Over the years, Haendler & Natermann has brought us some of the most interesting designs in the pellet world.

Starting from a strong base of Match Wad Cutters (their Finale Match line), H&N introduced many years ago, the "Crow Magnum", then under exclusivity to Beeman, and now available directly under their own brand.
They supported the initial trend towards heavier pellets and more powerful airguns by making the Barracuda Match more than 20 years ago and, more recently, they introduced more options for the hunter and long range shooter in heavier hollow points, larger calibers and heavier-for-caliber pellets suitable only for the most powerful PCP's, some even needing special barrels.

They have also embraced wholeheartedly the non-lead trend that, whether we like or not will prevail in the long run, with the "Silver pellets": Barracuda Green and Field Target Trophy Green and their "Golden" ("Power") pellets that encapsulate the lead content and therefore prevents the skin to lead contact some people are becoming wary of.

Less than two years ago, H&N relocated the plant and the machines, re-vamped and streamlined its production. It was a huge financial, logistical, human and technological effort on their part to do this and still keep on going with the supply, the development and all the intense activity that goes hand in hand with a world-class company that supplies a good part of the Olympic shooters and Top of the World aspiring shooters everywhere. Yes we lost some products (like the EXCELLENT 0.20" cal. Lasers) , but the results have been nothing less than amazing.

Not all companies were so lucky. Some pellet companies failed, or decided to close given the increasing restrictions, regulations and difficulties that go hand in hand with the lead raw material; and designs that were interesting were about to be lost. Except that H&N saw the opportunity where others saw the problem and when PAX (UK) decided to sell, they were ready to buy. PAX was making in the UK the "Range Master", "Pile Driver", "Dynamics" as well as some Prometheus pellets.

And so it happened that they bought the whole operation, "lock, stock and barrel", and moved it to Germany.

Fast forward almost a year and half and we now have the first results of that vision.

H&N has been a long time supporter of FT and was kind enough to send some of the first samples to come out of the Sniper line. They admit that the line is not running as smoothly as they like (some skirts are "wavy"), and the offerings are, for now, limited to the 4.50 head diameter. In the future, the Sniper line will also offer the 4.52 mm's head diameter for those of us that shoot non-Match barrels.

On the commercial side, Pyramyd Air now shows at least 6 pellets that are the result of these efforts, among which are the Excite Dynamics ; the Pile Drivers; and our pellets of interest for this post: the Sniper Medium, and the Sniper Light.

So, ¿what makes these pellets so interesting? 

Look at them and think in terms of location of Center of Gravity and Center of Pressure:
Picture
Also think in terms of air seal and deformation upon firing.

In all these areas, the design of these pellets excels. Center of gravity will be as forward as can be, given the weight of the pellets (7.5, 8.5 and 15 grains respectively). This emphasizes the "shuttle-cock" effect and adds stability to the pellet.

Center of pressure will be a little bit in front of geometrical center, which should make these pellets less susceptible to vertical deflection with side winds.

Because of the "Column" shape, they will exit the barrel pretty much as they went in. Preserving the BC. And the relatively thin skirt affords a good seal at any pressure above 80 BAR's.

So, ¿how do they shoot?

The answer is that it depends on your barrel, as usual. Some barrels will like them, some will not.

A big disadvantage, for the time being as stated above, is that H&N is offering only the 4.50 head diameter.

When testing, bear in mind this and compare with other pellets in the same head diameter out of YOUR rifle.

That is what I did and these are the results:
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The bottom left target shows two five shot groups one with Sniper Mediums, the other with Sniper Lights shot at 20 meters (around 22 yards).
All other groups were shot at 32 meters (35 yards).
The bottom right is a 5 shot group with Sniper Lights.
The top left is a 5 shot group with Sniper Mediums
I did not test the Sniper Magnums because I do not have anything setup to shoot 15 grain 0.177" cal. pellets at present.

For comparison, the center target shows the two sighters and a 5 shot group with JSB Exact 8.44's, the top right target shows TWO 5 shot groups (8 clicks apart) with JSB Exacts 8.44's.

There are a few holes (labelled BMG) made by Barracuda Magnum Green's, but that is another story.

As you can see, the Sniper line shows potential. The accuracy obtained is on par with what would have been obtained using other high quality pellets in the specific head diameter (4.50) in this gun (my CCA WFTF D-54).

All pellets were lubed with "Boe Shield / T-9"

If you do have a Match barrel in any old gun, test the Sniper Light. It might prove an interesting pellet; and if you do not have a Match barrel anywhere, then try some but  be aware that in the near future they WILL be available in 4.52, so keep an eye out for them!

Keep well and shoot straight!





HM
10 Comments

Serendipity

5/2/2015

6 Comments

 
In VERY FEW cases, we know EXACTLY how, why, where and by whom a word was created. Serendipity is one of those words.
Although it is now widely understood as having to do with luck of some sort. In the original meaning it meant the capacity of making fortunate discoveries seemingly by chance but, in truth, due to acute observations of reality and, possibly, a good memory.

A few months ago, a friend asked me to get his D54 up to snuff for Hunter FT. I told him that I was no longer accepting unknown project guns without an Analysis and Diagnostic phase, because in many occasions, I had undertook a project only to find out that the gun was neither as pristine, nor as accurate as the owner / purchasor was led to believe.

This may have put him off a little because he dropped the idea of having a professional work on the gun and tackled the gun himself. So, a few more months passed.

Suddenly, I get this Email that said that he had played with the gun and he simply could not make it shoot as he thought the gun should. He had changed springs and guides and tried several pellets, but no matter what, the gun shot between 9 and 25 mm's at 30 meters using Exacts 8.44's/4.52's @ 925 fps.

Again, the same "spiel" about the need to get a full A&D phase scheduled and budgeted into the project, only that this time, he took me up on the offer.

And so, the gun arrived. A nice 54 of "intermediate" vintage. T-01 trigger on one side, but the modern round-bellied stock of the current series.

The first thing I did was to chrono the gun when it got here. Lo and behold, the MV's were all over the place! 

A consistent MV (within 17-20 fps in 0.177" cal. or 25-30 fps in 0.22" cal. maximum spreads) is necessary to get good accuracy. It is not a sufficient condition, however. Many guns have produced spectacular chrono strings only to disappoint at the target. 

This gun, however showed extreme spreads of 40 fps (out of 900); this was too much, and even just blowing with lung power into the barrel at both piston positions (cocked and uncocked), showed that the piston seal and the breech seal were leaking. Tore apart the gun and went through a complete re-seal. While the gun was apart, it was clear that someone had attempted a "tune" with a hone/polish. The battery of tests for compression, resilience and rail speed of the piston proved very enlightening. We could now ascertain that the gun would not shoot the heavies fast enough. Remember, up to this point I was trying to follow conventional wisdom and experience that tell us that pellets do not fly well at speeds much higher than 875 fps..

At this point in the story, winter fell on us with a vengeance, and so we tried our best to keep going with whatever short range tests and tools we could.

While giving the barrel a really good cleanout, I detected that the gun had a 'largeish" bore, so some tests were conducted with 4.53 mm's headed JSB Exacts that I always have some around, thanks to Bori at Top Gun Airgun and, yes the diference was quite amazing. The groups started to behave like groups, not patterns.

As soon as the weather allowed, 32 meters testing was conducted, the results are here:
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You can clearly see how the 4.53 pellets yield better results.

BUT, what about other pellets?

Short range tests had pointed to the interesting possibility of using JSB Expresses. At 7.9 grains, these pellets have demonstrated pretty good BC's and are reasonably accurate at WFTF levels, being the preferred pellet of MANY of the shooters at the top but, again, common wisdom and conventional thinking told me that this gun at full power could not possibly be shooting the Expresses well.

Still, a scientist will not rest till the rule, or the exception, is proven, so we shot a few groups with Barracuda Match 4.53 and some with Expresses (labelled Xp's):
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Some groups were better than others, but in general, the Expresses showed very good accuracy at 32 meters.
When I chronoed the gun I was surprised to see that the gun was shooting the Xp's at 993 fps with a standard deviation of 4 fps for 17.3 ft-lbs of muzzle energy.

So, the questions became ¿WHY?, ¿HOW?  This seemed to go against all experience.

Well, the first step was to capture a pellet from the gun without further deformation. It was important to register what FINAL SHAPE the pellet had acquired after being fired at that speed.
Since my experiments of "Deformation upon Firing" of some years ago, I had not captured too many pellets, so I fished for my capture tube, found it and set it at 20 meters.


Here is what we found when we unraveled all the Dacron fibers:
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Clearly the pellet had "Blown Out" but still retained basically a good shape. Waists had also "fattened" up a bit
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To give you an idea, Xp's waists usually grow HALF what they grow in this gun when shot at 12 ft/lbs from most guns; from 0.128" to 0.130" . This rifle showed double that deformation, but still retained the shape of the pellet. BOTH this things were conducive to good accuracy.
Now, WHAT was providing that back force to allow the pressure to build up inside the compression chamber so as to cause this "upset" of the projectile, to use the proper ballistic term?

The answer is in the photo. The rifling is not quite the Diana standard rifling. Such deep, narrow grooves is not what we normally expect.

My THEORY is that this barrel was rifled TWICE.

We need to work more with this because it is a very interesting occurrence. Perhaps it is a fluke, perhaps it is not. But definitely this merits some really serious ballistic work.

Now, regardless of the accuracy, the BC DID SUFFER. From the normal 0.021 and upwards (some WFTF shooters report BC's as high as 0.026 for the Xp's from their barrels) to what was actually measured in this case of 0.018 the difference is small, but not negligible.

However, we must not loose sight of the PURPOSE of the rifle. This is a Hunter FT rifle, and so a very high BC is not as desirable as a high MV is.

Analyze this graph:
Picture
The Red trajectory is the Xp's at 993 fps. The Green trajectory is the JSB Heavies at 840 fps, the Blue trajectory is what WFTF shooters would hope to get from their rigs and is only there for comparison. On the right hand vertical axis we have the divisions corresponding to a ¼ mrad spacing. On the left vertical axis we have inches of drop.

All trajectories have been maximized for range. All setups are identical in scope height.

Our shooter is shooting HFT, so his Scope is 12X, but there are good scopes that offer ½ mrad at 12X, so that allows us to use ¼ mrads for rangefinding and for holdoff's. With ¼ mrads our range estimating error by bracketing can be of up to 4 yards at the max range. This means we could mistake a 55 yard target for a 51 yard target (based on the common dimensions found on targets).

So, if the error is 4 yards, and we shoot a 55 yard target as if it was a 51 yarder, that means that the shooter will estimate the 2nd ¼ mark down, which would be correct, but the target is really at 55, so the shot will land ½" LOW, BUT since at this range the minimum KZ size is 1.5", it means that his shot should still land within the KZ.

Now, the WIND . . . is another matter altogether. But there are much better probabilities of being able to rangefind well than to estimate wind well. So, that is why we look for the most advantages in the ranging.

Overall, it was a VERY interesting project and it shows an interesting avenue of research into rifling designs.

Keep well and shoot straight!


HM
6 Comments

    Hector Medina

    2012 US National WFTF Spring Piston Champion
    2012 WFTF Spring Piston Grand Prix Winner
    2013 World's WFTF Spring Piston 7th place
    2014 Texas State WFTF Piston Champion
    2014 World's WFTF Spring Piston 5th place.
    2015 Maine State Champion WFTF Piston
    2015 Massachusetts State Champion WFTF Piston
    2015 New York State Champion WFTF Piston
    2015 US National WFTF Piston 2nd Place
    2016 Canadian WFTF Piston Champion
    2016 Pyramyd Air Cup WFTF Piston 1st Place
    2017 US Nationals Open Piston 3rd Place
    2018 WFTC's Member of Team USA Champion Springers
    2018 WFTC's 4th place Veteran Springer
    2020 Puerto Rico GP Piston First Place
    2020 NC State Championships 1st Place Piston
    2022 Maryland State Champion WFTF 
    2022 WFTC's Italy Member of TEAM USA 2nd place Springers
    2022 WFTC's Italy
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