Can't stop my coal from lengthening when chambering in AR

[wildfowler]

I have used the sierra 110 grain hollowpoint, the Speer TNT 125, the Barnes Blacktip, 200 grain Sierra match King, 220 grain Sierra match King, and 220 grain Sierra round nose.

The only thing I have not tried to change because I haven't loaded any black out in a few years now, is to chamfer the brass with the standard angle chamfer tool instead of the VLD angle tool.

I've tried using my lee factory crimp die set to just lightly kiss the case neck, to all the way tightened down to the point where it grossly deforms the bullet, and virtually every combination between those two points with the same results.

From my observations, using the stainless steel wet tumble brass cleaning method did seem to reduce the bullet pull slightly but did not eliminate it.

I'm in the process of putting together a model seven 300 blackout, so hopefully it will be more accurate than my AR is which is not so bad that I really complain. I just know that it's happening in my AR.

My upper receiver is a noveske 10 inch factory upper receiver. I don't know off the top of my head which carrier they supplied me with.

Does anyone happen to know if the blackout was intended to be operated using an A.R. 15 carrier, or an M-16 carrier that is heavier?

Thanks.

[Bgd]

Just received the LC brass and preliminary results are. The coal does not grow with a coal of 2.0 and no crimp. Thank you everyone for your help. Now does anyone's want to buy 1000 new federal cases? Oh well live and learn. I have one of those fancy JP buffer springs coming also, and a bunch of bullets to try. This calls for a celebration. thought I was going crazy there for a while.

[xdmalder]

Glad to help.

[dellet]

Just received the LC brass and preliminary results are. The coal does not grow with a coal of 2.0 and no crimp. Thank you everyone for your help. Now does anyone's want to buy 1000 new federal cases? Oh well live and learn. I have one of those fancy JP buffer springs coming also, and a bunch of bullets to try. This calls for a celebration. thought I was going crazy there for a while.

Before you sell them, fire a few and see what happens when you load them a again.

[Bgd]

Just received the LC brass and preliminary results are. The coal does not grow with a coal of 2.0 and no crimp. Thank you everyone for your help. Now does anyone's want to buy 1000 new federal cases? Oh well live and learn. I have one of those fancy JP buffer springs coming also, and a bunch of bullets to try. This calls for a celebration. thought I was going crazy there for a while.

Before you sell them, fire a few and see what happens when you load them a again.

It will be interesting to see if the FC brass will work with the JP captured buffer spring when it comes in.

[Bgd]

Found this article where the author talks about bullet walk out. Thought it was interesting since it is what I am seeing. The LC brass helped quite a bit but the are still moving forward in the case by about .003. I haven't had a chance to reload for a while but when I can get back to it I am going to try seating the bullets to take advantage of the entire neck. In this article het says he removed the expander completely. I may try that.

The JP captured spring made no difference in bullet walk out. I just tried the standard spring.

https://www.shootingillustrated.com/art ... -blackout/

[IMGrunt]

.003? Don't start measuring and weighing your bullets...you will be admitting yourself to the nearest psychiatric ward. Honestly, at .003 you can probably make better use of your time doing other things to increase accuracy of your loads. .003 - .007 for factory is not that unusual from what I've read.

[Banjo51]

Just received the LC brass and preliminary results are. The coal does not grow with a coal of 2.0 and no crimp. Thank you everyone for your help. Now does anyone's want to buy 1000 new federal cases? Oh well live and learn. I have one of those fancy JP buffer springs coming also, and a bunch of bullets to try. This calls for a celebration. thought I was going crazy there for a while.

Before you sell them, fire a few and see what happens when you load them a again.

It will be interesting to see if the FC brass will work with the JP captured buffer spring when it comes in.

I have the JP silentspring and have the same issue. Came here looking for answers and found this thread. I am using Federal once fired brass. I also found that it happens with several other factory ammos that are 220gr. I thought about reducing the spring power to see if that would improve the bullet jumping issue,but wasn't sure if I would get cycling issues.??

Also have a issue of what I believe is the feed ramps placing to scratches on the bullet and brass, some of the brass I had to chunk it was so bad. Any ideas.

[Bgd]

Before you sell them, fire a few and see what happens when you load them a again.

It will be interesting to see if the FC brass will work with the JP captured buffer spring when it comes in.

I have the JP silentspring and have the same issue. Came here looking for answers and found this thread. I am using Federal once fired brass. I also found that it happens with several other factory ammos that are 220gr. I thought about reducing the spring power to see if that would improve the bullet jumping issue,but wasn't sure if I would get cycling issues.??

Also have a issue of what I believe is the feed ramps placing to scratches on the bullet and brass, some of the brass I had to chunk it was so bad. Any ideas.

when I have a chance I am going to seat some dummy rounds with brass seized without the expander button. I have several bullets to try. Will let you know. Switching to LC headstamp once converted 223 brass helped lots. The bullet moves out about .003 instead of .010 or more. When I load up some live rounds I am going to use 296 or lil gun and make sure it is not a compressed load. From what I have seen a compressed load causes the bullet to move out of the case even more when chambered in an AR.

As far as the scratches I have seen scratches but the are just superficial and on the bullets also. Polishing the feed ramps may help I don't know.

When I installed the JP silent captured spring I didn't notice a difference. Playing with the springs or an adjustable gas block would be fun but that will be for another day for me. I need about 2 weeks vacation to play.

I am concentrating on light supersonic loads for deer hunting with my kids. Probably why I have become a perfectionist about it. My kids will be shooting them, I want no surprises.

[IMGrunt]

Enjoy your journey. It's all fun as long as you're having fun. Some info to help with your continued journey. Neck tension, bushing dies and then...(not my words)
Bullet grip is affected by many things, such as:
1. Neck-wall thickness.
2. Amount of bearing surface (shank) in the neck.
3. Surface condition inside of neck (residual carbon can act as a lubricant; ultrasonic cleaning makes necks “grabby”).
4. Length of neck.
5. Whether or not the bullets have an anti-friction coating.
6. The springiness of the brass (which is related to degree of work-hardening; number of firings etc.)
7. The bullet jacket material.
8. The outside diameter of the bullet and whether it has a pressure ridge.
9. The time duration between bullet seating and actual firing (necks can stiffen with time).
10. How often the brass is annealed