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I would use a bushing die to set neck tension to about .004"
I run SAC bushing as they create a soft taper. I also think you will retain better accuracy over a crimp.
I run SAC bushing as they create a soft taper. I also think you will retain better accuracy over a crimp.
Sized a piece of Alpha brass and set the neck tension to .004. Seated a bullet in the empty case then loaded it in a mag and let the bolt go forward. The 90 grain ATIP ended up being pushed in .003 & .005”. I’m wondering if that will be mitigated by a powdered case? I’m using STABAL HD right now and per the Hogdgon load data I’m using a compressed charge at the 46 grain max. Actually it is compressed at 45 grains and up.
Measure that loaded round at the neck just to make sure you hit 004. Otherwise could you have hit the lands?
I know there is less surface area on the 22, but 004 should still hold it.
Post up your measurment and I'll run some numbers.
ETA: Going down to the 22 from say 6.5 is a 22% reduction(roughly) in surface area(holding/coefficient of friction loss).
I know there is less surface area on the 22, but 004 should still hold it.
Post up your measurment and I'll run some numbers.
ETA: Going down to the 22 from say 6.5 is a 22% reduction(roughly) in surface area(holding/coefficient of friction loss).
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Have you ever measured gas-operated chambering cartridges in non-crimped 5.56 showing a different COL after being cycled by the action under fire?
Yes I have, few thousands of an inch. Which is why, per the advice i received from the tech support guy at Berger bullets, I put an ever so slight crimp on them with the Lee factory crimp die I have.
I haven’t seen them move with 6.5.
Is that with 80s and heavier? I could see that with the mass-to-neck tension surface area ratio.
I know I’ve never crimped Grendel or 5.56, but I don’t load over 77gr in 5.56. The main concern for me if it was happening would be COL-growth inside the mag hanging up on the front magazine wall and retarding the cartridge lift.
At the time it was the Berger 77s if I remember correctly. I now use 77 grain TMKs & 73 grain ELDX with a slight crimp. ES for each loading stays under 20fps.
With 5.56 it never happened in the mag, just when chambered, inertia likely.
With the AR10 and the stronger bufferspring and heavier bullet it happens when chambering to a much more significant degree than an AR15 running 5.56. But it’s the opposite, prior to crimping the 5.56 bullet would move forward a few thousands, with the 22 CM the bullet gets stuffed into the case .003-.005”. I’m thinking it’s hitting the feed ramp pretty hard based on the denting of the aluminum tip.
Have you tried de-edging, blending, and polishing both your feed ramps on the AR-10?
GAP did my .260 Rem nicely before they ever offered the GAP-10. I used to send them all the parts minus the barrel and let them work their ways. Never had a FTFeed in either .308 or .260 Rem, and they sent back lasers.
MagpulMy next question was about visual impacts on the bullet and brass so that's answers that
What mags are you using
I have not had a chance to try that. No failure to feeds yet, just damage to the aluminum tip on the ATIP.
