338 Bullet Testing / Demonstration LV Nev.

#202
Re: 338 Bullet Testing / Demonstration LV Nev.

I wish to thank everyone that conducted the tstting and also Frank for making it happen. Hopefuly the pissing match can now stop and people can just get along.

I have tested various bullets over the years and conducted testing for Nick and it does not matter what BC you can achieve the projectiles must still be accurate so i hope the new designs of projectiles can shine using these results to show where improvement can come from and the accuracy results are going to be Key.

I believe that a projectile should be able to shoot well out of a variety of rifling configerations for standard calibres and if a projectile with a hige BC can do that it will be the one people will buy.

Thanks again
 
#204
Re: 338 Bullet Testing / Demonstration LV Nev.

A few thoughts on the test results:

Some here may recall Francis's introduction at the Hide over a year ago. Nick Collier provided him with a represenative drawing, in Solid Works, of a banded 375 projectile to perform CFD analysis upon. To the astonishment of both me, and the beta-tester who calculated a ZA375 field BC, the surface drag associated with engraving-bands was 20 Newtons. It seemed that this could not be correct, but it appears this was closer to reality than appreciated at the time.

If this drag is scaled to the ZA338, we are looking at 18 Newtons, or the equivalent of a spring attached to the base of the bullet with a constant 4 pound force applied in the direction opposite of flight. This drag needs to be eliminated, but one might ask; "Why retain engraving-bands at all?". The answer is simple; they allow approximately 150 fps greater muzzle velocity at the same peak chamber pressure, and afford the structural integrity to drive a projectile up to Mach 3... the velocity at which the nose ogives typically used lose efficiency.

What is encouraging about this test is that, notwithstanding an incredible amount of parasitic band drag, the ZA's high aspect ratio Von Karman nose still produced the best form factor:

ZA (278 grain) - .4835
Berger (300 grain) - .4897
Sierra (300 grain) - .5022

The lower the number, the better. If the 22 grain disparity is corrected, as can be easily accomplished through the use of a PDT core, the BC numbers look like this:

ZA- .776
Berger- .766
Sierra- .747

This is for illustrative purposes only. Obviously, ZA is not interested in improvement at the margins. It must dominate existing projectiles in order to justify the technology, and the system will do just that.

This will be an exciting year.


 
#208
Re: 338 Bullet Testing / Demonstration LV Nev.

Tim, Dont count out the solids yet. As Lowlight said, " From the numbers side of things, the most impressive load I saw was the predator solids loaded by SW Ammo, they were mag length and going 3130fps + and we're very consistent. These projectiles are also very accurate. This is one reason we dont advertise BC's. If you just go by the numbers, things look on the bleak side. But the balistic performance is where the money is. As far as we are concerned, I welcome any chance to make our projectiles better, but i will not sacrifice accuracy and performance for a higher BC. The next test will be a lot more fun for the guys.
Thanks again for all the hard work and long days.
 
#209
Re: 338 Bullet Testing / Demonstration LV Nev.

For the sake of the discussion take the Lehigh bullet with a bc of .651 you could probably do about 3100 out of a 28in barrel with VV570 but I can do that with a 250 Scenar for half the cost almost the same bc. I thought the whole principle behind solid bullets was to have a lighter design with the same BC?

If they were less than 10% behind the SMK but 50 or more grains lighter great but plugging these numbers into JBM its not looking so good especially in the wind.
 
#213
Re: 338 Bullet Testing / Demonstration LV Nev.

Thanks for all your work doing the testing and posting the results. We don't have much of the equipment or skill to test at ELR, so velocity and accuracy testing is done out to about 300. Its great to benefit from the testing of a third party.

I was surprised to see the low BCs for the solids. If my numbers are right, it looks like the 235 Predators will be subsonic around 1600. We have had several customers, most 'Hide members, report success at ranges in excess of 2k with this same load. Could the unique design of the solids make them more stable and accurate at subsonc velocities than other types of bullets?

Mike

 
#214
Re: 338 Bullet Testing / Demonstration LV Nev.

Mike,

Mass, and dimensional, uniformity weigh in favor of turned solids... everything else works against them. The way to compensate is through increased spin rate, high density cores, or both.

There is no free lunch.
 
#215
Re: 338 Bullet Testing / Demonstration LV Nev.

Good work lads.
Its great to see shooters get together and invest in this sort of testing for the benefit of other shooters.

I have plenty of questions about the results but will ask only one at this stage. Does the results indicate that the BC for the solids can be used for all super sonic velocities or does the BC of the solids change dramatically with the velocity?
It has been said that the BC of solids can vary by up to 60% depending on the velocity. Is this validated by the test results?
 
#216
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ply1951guy</div><div class="ubbcode-body">Perhaps at some later date Mr. Litz and KnS Ballistic Services will have the opportunity to discuss the issue at length and endeavor to explain the anomalies noted.</div></div>


As mentioned above, we were looking to discuss the results with Mr. Litz and look for potential sources of error in either/both testing scenarios.

I can tell you that we had a great conversation last night and discussed "how we done it" from both perspectives. Mr. Litz discussed his test setup and we discussed ours, spent a good bit of time talking about potential setup issues and what each group did to mitigate/eliminate them.

Currently none of us has a definitive answer to why there is a discrepancy. The three of us do have some potential theories but not something any of us is ready to hang our hats on just yet. Geographically we're not too far apart and we've discussed getting some range time in a facility midway between us to test both acoustic systems in parallel. While this proposal is in its infancy I can say that KnS Ballistics is looking forward to the collaborative effort.

The end goal & end result of this testing is that it benefits the long range shooting enthusiast, which includes Mr. Litz, myself and Francis. As we have more information regarding this particular topic one of the 3 of us can offer it for discussion.

I'd like to thank Mr. Litz for taking the time from his evening to have the discussion. Francis and I both look forward to talking with him further and bringing this type of testing forward in development to benefit the industry.


Bryan, thanks again.
 
#217
Re: 338 Bullet Testing / Demonstration LV Nev.

To distinctly address Mike's question RE: the SouthWest offerings with Predator solids in them.

The anecdotal evidence of effectiveness at 2kyd bodes well for that projectile and especially for your loaded ammunition. It doesn't much matter how good a projectile is if the ammunition isn't up to snuff with it.

Your customers having success at those ranges is good to hear for a number of reasons, however without further information it is very difficult to make any definitive attempt to answer your inquiry.

You are correct in saying that with the BC reported the load drops below Mach 1.0 around 1600yd downrange, which I confirmed when I ran it through JBM with the assumed value of 0' DA. When I ran the simulation in JBM for the following density altitude values the results change substantially:

DA Mach 1
crossing
0' = 1525
2000' = 1650
4000' = 1750
6000' = 1900
12,000' = 2350

I've asked JeffVN what DA's he sees in the summertime in this area and values over 5000-6000ft are not uncommon. Frank has stated in some of his online training videos regarding DA values over 12000' ASL.

So without atmospheric details it would be irresponsible for me to suppose anything from the anecdotal support that the 235 Predator works past the sound barrier.

That's certainly not to detract from anything that your company produces in any manner, I just can't give you a better answer than that at this time.

Hope this helps.
=================================================================




To those who have asked about potential accuracy, accuracy downrange through subsonic, et al.

There is not enough information from this test to make any definitive statements to the efficacy of anything downrange. Like discussed previously, there was 1 goal in this test and that was to gather data for reporting the various ballistic coefficients.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">We also did not test for subsonic transition stability due to safety reasons. </div></div>

It does not support one theory or another for transonic or subsonic efficacy on target, as the medical doctors say "inconclusive".
 
#218
Re: 338 Bullet Testing / Demonstration LV Nev.

Wadcutter, based on these results, I can say that there is larger variation of the BC with the solid bullets compared to the jacketed bullets. For most jacketed bullets tested, we routinely got about 0.75 percent variation across all the shots. Here, percent variation used in the statistical sense, defined as % var = SD/Mean. As for the solids we saw percent variations in the 1.25 % to 1.5 % realm. As for the magnitudes of the variations, I can not say anything towards the 60% number that Mr Litz published in the second edition of his book since we did not perform our post processing the exact same way. So yes, we see more BC variation on the solid projectiles, but I can not speak to the exact magnitude of the variation based solely on these test results.

Either way, using the averaged G7 BC that we listed for any of the solids should result in very good trajectories right out of the gate, assuming the shooter is armed with a good muzzle velocity figure and good atmospherics.
 
#219
Re: 338 Bullet Testing / Demonstration LV Nev.

Thanks for the test guys!

I wonder if ole Trigger50 was right? (discussion here on the Hide years ago) about banded solids and referring to the bands as "drag bands"

IIRC he did a lot of testing on the 408CT and 375CT with various configurations of projectiles. Jamison solids were non banded and performed amazingly well for me at distance in my 375CT.

If this question isn't appropriate on this thread just delete it.

I'm not trying to start an argument.It's just that BC's for the solids weren't nearly as high as I had anticipated and the SMK's BC was quite a surprise.
 
#220
Re: 338 Bullet Testing / Demonstration LV Nev.

Steve,

I think your question is perfectly appropriate to context.

When Alfred Krupp created this design feature for his artillery shells in the the 1860s, his engineers had very little understanding of aeroballistics. They thought in terms of mechanics, and this was an elegant solution to the demands of his new, cast steel, breech loading cannons.

It is not generally publicized, but Krupp eventually invested in his own test range that exceeded the capabilities of the Prussian government facilities. By the time his daughter married, and her husband Gustav inherited both the wealth, and the name, of Krupp... the multiple bands had disappeared from Krupp designs.

In the great war, the Long Max made its debut, later to become known to the Allies as the "Paris Gun". These shells were 5.4 calibers in length, and utilized only two engraving bands. They had a range of 75 miles, and spent a portion of their trajectory in the vacuum of space.

This configuration is not adaptable to small arms. Given the relatively small Reynolds numbers, it was not apparent to me there was any purpose in trying.

I was wrong, but not irredeemably so.

The internal ballistic advantages of multiple bands can be preserved, while taking full advantage of an ultra low form factor. In general terms, the Lost River bullet still takes a backseat to the banded designs... we are now looking at eclipsing both in terms of performance.
 
#221
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ply1951guy</div><div class="ubbcode-body">Wadcutter, based on these results, I can say that there is larger variation of the BC with the solid bullets compared to the jacketed bullets. For most jacketed bullets tested, we routinely got about 0.75 percent variation across all the shots. Here, percent variation used in the statistical sense, defined as % var = SD/Mean. As for the solids we saw percent variations in the 1.25 % to 1.5 % realm. As for the magnitudes of the variations, I can not say anything towards the 60% number that Mr Litz published in the second edition of his book since we did not perform our post processing the exact same way. So yes, we see more BC variation on the solid projectiles, but I can not speak to the exact magnitude of the variation based solely on these test results.

Either way, using the averaged G7 BC that we listed for any of the solids should result in very good trajectories right out of the gate, assuming the shooter is armed with a good muzzle velocity figure and good atmospherics. </div></div>
ply1951guy,
Thanks for your reply.
I have some records of my range testing with the 235gn Predator projectile. I also have a bunch of them left in the shed so will shoot them over the next few weeks using your measured G7 BC and see how they go. I do know that they were very accurate but did not survive transonic transition in my rifle at just above sea level.
Also can you tell me what twist rate the barrels were that tested the 300gn Berger bullets? Thanks.
 
#222
Re: 338 Bullet Testing / Demonstration LV Nev.

All:

I was a bit surprised at the apparent "surprise" evidenced in posts made after the results were published, about the "poor" showing of the "solids" vs the Berger and SMK. Here's why I was surprised:

1. Looking at the Berger website (http://www.bergerbullets.com/Products/Target%20Bullets.html), there is a very definite relation between bullet weight and BC. Specifically, if you run some number, and consider the Berger "Match Target Hybrid" series in 30 cal (insufficient data points in .338), you get these results (bullet weight divided by here-published acoustically-derived G7 BC):

168 gr yields 631.6
185 gr yields 635.7
200 gr yields 625
215 gr yields 603.9
230 gr yields 605.3

To me these results suggests a very definite relation of BC to weight with some tapering off as the weight increases.

2. If you then scale up the test results by the difference in bullet weight (300 divided by the weight of bullet X) you get the following scaled up G7 values (in the order the test results were posted, that is, bullet #):

SMK 300 - no change at .380
HDY 285 - .366
Lehigh 245 - .408
GSC 232 - .385
Predator 235 - .360
Berger 300 - no change at .389
ZA 276 - .393
To me this suggests that lengthening the lower weight projectiles enough to reach 300 gr (no nose or tail changes - which is what I assume is approximately the case with the Berger 30's) would yield a rather tight G7 grouping, .360 - .408.

My conclusion, the lower BCs for lower weight bullet is to be fully expected AND rationalizing those test G7 numbers by the disparity in weight suggests that the BCs of all these projectiles is so close (again, .360 - .408) as to be relatively meaningless in the context of projectile application, that is, shooting and hitting your target. Short answer, "within the range of designs considered, the demonstrated BCs are in line with projectile weight...now lets move on."

So...on to "Phase 2: Accuracy at ELR Distances".
 
#223
Re: 338 Bullet Testing / Demonstration LV Nev.

ELR,

I dare say that virtually every person reading this thread realizes that there is a "relation" between BC, and weight.

There actually are (this may surprise you) some "very definite" mathematics which describe this relationship... among others.

Nobody here has defined a "context of projectile application", but if you are suggesting that there is a "relatively meaningless" disparity in the projectiles tested, then you might reconsider contributing to this thread.

That statement is not only factually incorrect, but annoyingly distracting.
 
#224
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Mouse we tested to 1200 yards and change, everything remained supersonic as far as I know. </div></div>
I think Bryan tested to 500 or 600 yards? I confess I've no further clue on the cause of this BC discrepancy.
 
#225
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">ELR,

I dare say that virtually every person reading this thread realizes that there is a "relation" between BC, and weight.

There actually are (this may surprise you) some "very definite" mathematics which describe this relationship... among others.

Nobody here has defined a "context of projectile application", but if you are suggesting that there is a "relatively meaningless" disparity in the projectiles tested, then you might reconsider contributing to this thread.

That statement is not only factually incorrect, but annoyingly distracting. </div></div>

Just put the guy on ignore, he's a f'ing retard.
 
#226
Re: 338 Bullet Testing / Demonstration LV Nev.

We need to start some planning for the accuracy testing. The schedule here was issued today, so I know what I'm booked for right now. SHOT would be a fine spot to get together, at least those in attendance. I'd consider investing in a target cam system to make max use of time. Steel is already pre-positioned, adding some 4x8's for paper is easy. I'd like to get dates booked as far out as possible, so start looking at the calender.
 
#229
Re: 338 Bullet Testing / Demonstration LV Nev.

As the organizers consider the accuracy phase, please plan on capturing cartridge overall length for those shooters who might be considering an application in a repeater. Mile High lists the AI part that works in the AW series rifles and the AICS system as "2468 .338 Lapua 5 Shot Magazine" here - http://www.milehighshooting.com/index.cf...9&pageid=67 I don't see a listing for the 10 round version and have no idea whether the 10 round is more, less, or equally restrictive.

Also, please consider checking the cartridge case to ogive length to see whether the projectile is being pushed back into the case to allow it to chamber (that is, check it before chambering, chamber (don't discharge), eject, and check the length again). This would preferrably be done in a rifle with a factory chamber - AI, Remington, Sako. This will provide a heads-up on the impact of an application in a factory chamber for shooters that might consider using one of the longer projectiles in such a rifle.

Both the above basically looking at the "will it fit my rifle" issue. At least the results will suggest what the shooter will need to deal with to use the cartridge combos being shot.
 
#230
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ELR Researcher</div><div class="ubbcode-body">As the organizers consider the accuracy phase, please plan on capturing cartridge overall length for those shooters who might be considering an application in a repeater. Mile High lists the AI part that works in the AW series rifles and the AICS system as "2468 .338 Lapua 5 Shot Magazine" here - http://www.milehighshooting.com/index.cf...9&pageid=67 I don't see a listing for the 10 round version and have no idea whether the 10 round is more, less, or equally restrictive.

Also, please consider checking the cartridge case to ogive length to see whether the projectile is being pushed back into the case to allow it to chamber (that is, check it before chambering, chamber (don't discharge), eject, and check the length again). This would preferrably be done in a rifle with a factory chamber - AI, Remington, Sako. This will provide a heads-up on the impact of an application in a factory chamber for shooters that might consider using one of the longer projectiles in such a rifle.

Both the above basically looking at the "will it fit my rifle" issue. At least the results will suggest what the shooter will need to deal with to use the cartridge combos being shot. </div></div>

ELR you are here again and pushing your wants without helping. There are projectiles that will be tested that will shoot in YOUR rifle and others that will not. It is not up to you to make others conform to your opinions. the peojectiles that have already been tested and others that are due to be released all have diferent applications. some will be single shot only and that is fine for some and others will mag feed. also you are limiting the criteria to your chosen mag length. did you know that there is a new CIP AICS mag? it is .100" longer and designed for the 338 Lapua with 300gr projectiles so that also changes the criteria what mag do you want to be used the short AICS 338 lapua mag or the New AICS CIP 338 Lapua Mag or the mag we build all of our rifles with Seekins DBM with over 3.950" internal length?

How about you the people paying for the testing and supplying the projectiles and donating their time to make the test as transparent as possible and to help people to chose the projectile that suits their end use why would you reduce the peojectile pool that people will have to chose from. also i have access to a 338 Snipe Tac with a CheyTac bottom metal and mag so i can load nearly any projectile way out in the mag so would you discount the projectiles that i might want to use?

Lets just let the people who organised th first test to follow on with their planned format and Please Keep Out Of It.

Also the reason you dont see the 10 round mag is they dont make them.

I have taken the time to look over your website and you say you have a newer chamber print of the 338 Lap improved reamer do you realise it is a match reamer for neck turned cases? If you are going to sprout all of this information and be an expert make sure you clearly tell people that you are reccomending in case someone believes they can get your print copies and then build a rifle with them.





 
#231
Re: 338 Bullet Testing / Demonstration LV Nev.

The intent is to test the projectile performance, not create load data. If we optimize a load in a rifle, we can see how the bullet performs under best conditions FOR THAT RIFLE. If multiple rifles and loads shoot well, that will suggest the bullet works well and is tolerant of load conditions, which is highly desireable. Actually publishing the specific load data is probably not a good idea, all in all. I'd be happy just stating the powder type, distance off the lands and the muzzle velocity. After that, some small experimentation on the part of the end user should be all that's required.

LL, I'm at the house headed out the door, I'll post some date options in the AM.
 
#232
Re: 338 Bullet Testing / Demonstration LV Nev.

Wild Bill:

Please re-read my last post. I'm asking that info be captured and relayed so that potential users of the tested combos will have a heads-up as to whether those combos might work in their rifle and what they might need to do to use them, e,g., operate in single-shot mode. IMHO, that is what my post conveyed.

As for the reamer drawings posted on my site, they are not mine, they are from Pacific Tool and Gage. All the PTG drawings have a double asterisk referring the reader to this footnote at the bottom of the page, "** Chamber reamer drawings courtesy of Mr. Dave Kiff, Pacific Tool and Gauge". I included my note about one of the 338 LM Imp drawings ("NOTE: This drawing is more recent than the one in the package which includes the 338 LM") because there are TWO (2) such drawings on that page -"more recent" simply means one drawing has a later date than the other drawing. The package of drawings that I received from PTG included more that 10 drawings - inseparable since the file is a single PDF. The "more recent one" was received from PTG at on an earlier date. Reamer drawing names are somewhat meaningless - unless they are CIP or SAAMI - as the same name used on multiple drawings might relate to different specs on those drawings - in particular, in regards to throat depth and neck wall thickness. Nowhere do I "recommend" that anyone have a reamer produced and used without understanding what those dimensions mean. I suggest PTG be contacted if the reader is unfamiliar with the dimensions shown and/or how they might affect their application - tactical vs benchrest, etc.
 
#233
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ELR Researcher</div><div class="ubbcode-body">
Also, please consider checking the cartridge case to ogive length to see whether the projectile is being pushed back into the case to allow it to chamber (<span style="font-weight: bold">that is, check it before chambering, chamber (don't discharge), eject, and check the length again).</span> This would preferrably be done in a rifle with a factory chamber - AI, Remington, Sako. This will provide a heads-up on the impact of an application in a factory chamber for shooters that might consider using one of the longer projectiles in such a rifle.

Both the above basically looking at the "will it fit my rifle" issue. At least the results will suggest what the shooter will need to deal with to use the cartridge combos being shot. </div></div>

Really? This is a pretty ridiculous request in my opinion. I can see measuring base to ogive and distance to lans since this is an accuracy test and that data would be relevant since different bullets like different seating depths. (Of which is fairly well known depending on the bullet manufacturer and design) However your request of measuring, chambering, ejecting, measuring again is completely absurd.

I would sincerely suggest you go and buy an OAL gauge and learn a bit more about reloading before making requests. As an "ELR Researcher" and Im using that lightly after your above post, you seem to be a bit confused about some of the foundations of reloading and precision shooting.
 
#234
Re: 338 Bullet Testing / Demonstration LV Nev.

To those whom participated, spent your own money, time, and travel to generate these results I would like to say thanks, a big thanks. For someone to chime in and be critical of this fair and objective work at least unfair. From what I see to be a stage A, or testing #1 is a bit rude. What is also interesting is that this is real world, first hand generated data that was not copied and pasted from the internet and considered the gospel.
 
#235
Re: 338 Bullet Testing / Demonstration LV Nev.

Could the slightly lower than expected BC of the Berger 300 grain Hybrid be due to insufficient Gyroscopic stability in the first few hundred yards of their flight?
Thinking that the 1 : 10 twist barrels may not be imparting quite enough spin on these particular bullets.
 
#237
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wadcutter</div><div class="ubbcode-body">Could the slightly lower than expected BC of the Berger 300 grain Hybrid be due to insufficient Gyroscopic stability in the first few hundred yards of their flight?
Thinking that the 1 : 10 twist barrels may not be imparting quite enough spin on these particular bullets. </div></div>

We didn't use 1-10 barrels, we used Ashbury Intl Rifle with 1-9.4
 
#239
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wadcutter</div><div class="ubbcode-body">Could the slightly lower than expected BC of the Berger 300 grain Hybrid be due to insufficient Gyroscopic stability in the first few hundred yards of their flight?
Thinking that the 1 : 10 twist barrels may not be imparting quite enough spin on these particular bullets. </div></div>

We didn't use 1-10 barrels, we used Ashbury Intl Rifle with 1-9.4 </div></div>




What was the muzzle velocity?
 
#240
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: a-hull</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wadcutter</div><div class="ubbcode-body">Could the slightly lower than expected BC of the Berger 300 grain Hybrid be due to insufficient Gyroscopic stability in the first few hundred yards of their flight?
Thinking that the 1 : 10 twist barrels may not be imparting quite enough spin on these particular bullets. </div></div>

We didn't use 1-10 barrels, we used Ashbury Intl Rifle with 1-9.4 </div></div>




What was the muzzle velocity?</div></div>

Ah, every bullet type was different.

We had 3 Ashbury Rifles on the line we rotated them out per shot group.

All the loads were different, I know the Predators were around 3130fps but don't recall the rest, they hovered between 2800 and 3100
 
#241
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: a-hull</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wadcutter</div><div class="ubbcode-body">Could the slightly lower than expected BC of the Berger 300 grain Hybrid be due to insufficient Gyroscopic stability in the first few hundred yards of their flight?
Thinking that the 1 : 10 twist barrels may not be imparting quite enough spin on these particular bullets. </div></div>

We didn't use 1-10 barrels, we used Ashbury Intl Rifle with 1-9.4 </div></div>




What was the muzzle velocity?</div></div>

Ah, every bullet type was different.

We had 3 Ashbury Rifles on the line we rotated them out per shot group.

All the loads were different, I know the Predators were around 3130fps but don't recall the rest, they hovered between 2800 and 3100 </div></div>


Is it important for a person who wants to calibrate a ballistic calculator with the average b.c of a bullet in this test, to have an exact muzzle velocity for a paticular bullet tested, or is this still just some thing to get close? I am refering specifically to the berger test because it seemed to have the biggest difference between stated b.c and tested b.c.

And did they record the muzzle average velocities of each bullet group, so that it is available if someone wants it.
 
#242
Re: 338 Bullet Testing / Demonstration LV Nev.

The listed BC should be fine as a starting point for a load within a few hundred FPS of the tested velocity. The calculated values should get you pretty close, but be prepared to adjust them within any given program as much as 3-5 percent +/-.
 
#243
Re: 338 Bullet Testing / Demonstration LV Nev.

Muzzle velocity were recorded for everything but the muzzle velocity we recorded is of no use to you as it will be different in your rifle with your load.

The guys have the MV for each bullet fired, as well the information as recorded at each sets of data points downrange.

You can't necessarily use our MV for your calculations, just the BC as a started point as noted above.
 
#244
Re: 338 Bullet Testing / Demonstration LV Nev.

[/quote] Really? This is a pretty ridiculous request in my opinion. I can see measuring base to ogive and distance to lans since this is an accuracy test and that data would be relevant since different bullets like different seating depths. (Of which is fairly well known depending on the bullet manufacturer and design) However your request of measuring, chambering, ejecting, measuring again is completely absurd.

I would sincerely suggest you go and buy an OAL gauge and learn a bit more about reloading before making requests. As an "ELR Researcher" and Im using that lightly after your above post, you seem to be a bit confused about some of the foundations of reloading and precision shooting. [/quote]

Sir:

Possibly you have never tried what I suggested. FYI, I use two comparators, Sinclair's and Davidson's (Davidson's much preferred). I always check to determine if there is any push-back before loading with powder. If the bullet jams in the lands because the bullet was forced back into the case - and you have to unload during a match - there is a significant chance that you are going to dump powder. Possibly you have never shot benchrest. Quite a time consumer to clean out a load of powder if that happens. Only takes 2-3 test cases to check the actual OAL (as chambered) and adjust your seating die. Try it, you may be surprised.

As for the possiblility that Chandalar's last post referred to my recent posts, please reread those recent posts - none on them addressed Stage 1 (the already-concluded tests), only the next round, which appears to be the accuracy round. If you were not referring to my posts, please excuse my comment.
 
#245
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Muzzle velocity were recorded for everything but the muzzle velocity we recorded is of no use to you as it will be different in your rifle with your load.

The guys have the MV for each bullet fired, as well the information as recorded at each sets of data points downrange.

You can't necessarily use our MV for your calculations, just the BC as a started point as noted above. </div></div>


So the b.c. will change a little either way if the muzzle velocity is faster or slower, So start with the reported b.c's and adjust accordingly. Got it thanks.
 
#246
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wadcutter</div><div class="ubbcode-body">Could the slightly lower than expected BC of the Berger 300 grain Hybrid be due to insufficient Gyroscopic stability in the first few hundred yards of their flight?
Thinking that the 1 : 10 twist barrels may not be imparting quite enough spin on these particular bullets. </div></div>Here is my theory. Keep in mind that I'm quite novice in the designing projectiles, and not an ELR researcher in any way.

I think the lower B.C's seen from this test is because the B.C. was averaged over 1200 yards. As the bullet slows, the ogive profile may become less efficient as it was near say 3000 fps. If the test was conducted with the traps set at 100, 200, and 300 yards, I'm betting the values would have been higher. I also think this may be why (I think) the ZA projectiles did quite well for their weight. If they are running a true Von Karman Ogive, which is very efficient at high subsonic, and lower supersonic speeds, then their b.c. may not have fallen off as much as the others as they slowed down.

Like I said, I don't know too much about bullet design, or aerodynamics, I'm sure at this point Noel Carlson is miles ahead of me, but that's my swag.
 
#247
Re: 338 Bullet Testing / Demonstration LV Nev.

a-hull, every muzzle velocity recorded is listed in the PDF I posted, along with some basic statistics. I posted the link in my second post after the results post, it is there for everyone who wants to see it. Here is is again since you missed it.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ply1951guy</div><div class="ubbcode-body">Thanks for the nice words everyone.

I also put together a PDF with all the information about the fired rounds. It includes the atmospheric conditions for every shot, as well as the recorded muzzle velocity. I do not have any load data, but this shows more of the conditions of the testing.

Muzzle Velocity and Atmospheric Data from Test </div></div>
 
#248
Re: 338 Bullet Testing / Demonstration LV Nev.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ply1951guy</div><div class="ubbcode-body">a-hull, every muzzle velocity recorded is listed in the PDF I posted, along with some basic statistics. I posted the link in my second post after the results post, it is there for everyone who wants to see it. Here is is again since you missed it.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ply1951guy</div><div class="ubbcode-body">Thanks for the nice words everyone.

I also put together a PDF with all the information about the fired rounds. It includes the atmospheric conditions for every shot, as well as the recorded muzzle velocity. I do not have any load data, but this shows more of the conditions of the testing.

Muzzle Velocity and Atmospheric Data from Test </div></div> </div></div>





Thanks alot. I totally missed that.
 
#249
Re: 338 Bullet Testing / Demonstration LV Nev.

Makes the decision to go with the 300 SMK's very easy (at least BC/Price wise).

Very curious to see how the accuracy stacks up against the Berger.

Thanks for the test guys.
_DT
 
#250
Re: 338 Bullet Testing / Demonstration LV Nev.

Lowlight:

My belated Congratulations! You guys did a great, unbiased job. Fast and right to the point.

Going forward into the Accuracy phase, will you be opening up the field for more projectiles? I note that you mentioned - in response to a reader’s inquiry – that you could have also shot some of the Lapua scenars. Plus, sure there’d be interest in Noel Carlson’s latest design (he notes what you tested was an April 2009 version).

There are a lot of possibilities – see http://elr-resources.com/ELR%20Bullets_Projectiles%20Matrix%20338%2011132011.pdf

Might you consider posting an “open casting call” to other players?

Best regards and God Bless!
 
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