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Link Posted: 6/29/2022 8:10:21 PM EDT
[#1]
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Quoted:



First off, that gel is NOT the same as 10% ordnance gel.  I know it is advertised as such but does not create the same wound channel as true mixed powder 10% ordnance gel.  It offers less resistance to the bullet resulting in less expansion, less bullet damage, and deeper penetration.  A considerable amount of effort was put into the realistic recreation of living tissue for terminal performance by the DoD and various LE agencies, and there is a reason the FBI uses 10% ordnance gel for their testing and does not recommend the Clear Ballistics stuff.

https://www.thefirearmblog.com/blog/2016/09/09/clear-ballistics-gelatin-not-performing-like-real-ballistics-gelatin/
https://www.police1.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-iii-IbjkEYB93TAd5o6J/


Second, that is a single bullet.  Now try the same systems with the many available expanding cup&core bullets, as well as the other monolithics, and see how it goes. Spoiler alert because I've done the testing with the proper materials first-hand: Using a 1:5" twist significantly limits bullet selection if you care about terminal performance.  This is ESPECIALLY true through barriers such as those used in the FBI protocol.

If you don't care if a bullet that was designed for controlled consistent expansion behaves like a varmint bullet, then carry on.
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In the second link the clear block in the first pic clearly shows a BB calibration of around 3.74" which in the article the guy says exceeds FBI standards. But then goes on to says 2.95" to 3.74" is FBI specs. Not sure I understand that.

I'm interested to see proof of your claim as far as 1:5 twist 300BO barrels go. You've done the testing, as you say, so show us the results.

All you've submitted is an 8 year old article about clear ballistics and another showing the difference between synthetic and organic gelatin which is very contradictory.

I want to learn. Teach me. Hell, you may actually change my mind.
Link Posted: 6/29/2022 8:54:51 PM EDT
[#2]
Or look at it another way:

A super short barreled with 1/5 is a specialized role/application.

Therefore, it is appropriate to use specialized bullets to maximize the terminal effect of this specialized weapon. Monolithic expanding/fracturing monos are just that.

1/5 wasn’t chosen randomly.

Look at the 8.6blk with the 1/3 twist; expanding monos open faster and create larger permanent cavities with faster twist rates.

There is a lot of information out there on this.

But you’re correct in that conventional cup and core bullets are not optimal in this niche; and that’s okay.
Link Posted: 6/30/2022 10:42:36 AM EDT
[#3]
Specialized application and specialized bullets is a perfectly fine approach provided you're aware of the limitations as such.
Link Posted: 7/5/2022 2:43:11 PM EDT
[#4]
Just to update my progress:

Again my barrel is the Faxon 6” 1/5.

This barrel is terrible. I have now put 14 different loads through it and it is dinner plate accurate at 40 yards. I don’t see evidence of keyhole, just garbage groups… or rather patterns…

I square every receiver before install, have assembled way over 100 uppers, 20 years experience hand-loading including wildcatting, etc etc, tried two muzzle devices, 3 different cans, and this barrel will simply NOT group. I contacted Faxon. I’m pissed.  

Could simply be a sample of one, but wow. By far the worst barrel I have experienced.
Link Posted: 7/24/2022 7:03:57 PM EDT
[#5]
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DO NOT SHOOT CAVITY BACK 195gr MKZ through a 1/5.  Obviously the centrifugal force is causing the petals to open up in flight… good thing I tested this load with the baffles and end cap out of the can (used a Form 1 can).

190gd Sub X shoot real nice, as did a 220gr ELD-X load.

110gr Tac X shot terrible (proven load in my other blks) and some 150gr FMJ loads shot very well too.

ETA: this is a KAK 6.25” “baby blonde” 1/5 barrel. I replaced the Faxon
Link Posted: 7/25/2022 12:29:44 PM EDT
[#6]
That's cool.
Link Posted: 7/25/2022 1:12:29 PM EDT
[#7]
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Quoted:
That's cool.
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Not really. Would rather have them work normally.
Link Posted: 7/25/2022 1:41:22 PM EDT
[#8]
Link Posted: 7/25/2022 9:10:42 PM EDT
[#9]
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Sweet
Link Posted: 7/31/2022 10:55:44 AM EDT
[#10]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
https://www.ar15.com/media/mediaFiles/52686/101E3D05-2636-414B-B9BD-3C27005502FE_jpe-2464395.JPG

https://www.ar15.com/media/mediaFiles/52686/E16E90B7-B1FE-456D-8EAF-97653F1D0067_jpe-2464396.JPG

https://www.ar15.com/media/mediaFiles/52686/AE0AFF0A-E10C-4F17-AFAC-8BF41884794C_jpe-2464399.JPG

DO NOT SHOOT CAVITY BACK 195gr MKZ through a 1/5.  Obviously the centrifugal force is causing the petals to open up in flight… good thing I tested this load with the baffles and end cap out of the can (used a Form 1 can).

190gd Sub X shoot real nice, as did a 220gr ELD-X load.

110gr Tac X shot terrible (proven load in my other blks) and some 150gr FMJ loads shot very well too.

ETA: this is a KAK 6.25” “baby blonde” 1/5 barrel. I replaced the Faxon
View Quote

As we spoke about on the phone we are adjusting the subs to run in a 1:5 twist.
There should be a batch out soon.
Thank you for the input.

Robert
Link Posted: 8/1/2022 1:59:49 AM EDT
[#11]
Yup. Look forward to it
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