AR15 6 ARC brass over pressure signs

[Vava]

Hi all, I am new to reload for AR15. I reload 6 ARC with LeverEvolution and 103 ELD-X, COAL 2.26" , powder charge 30,2 grain, brass is Starline. Can someone more experienced look at the attached pictures to say whether there are any excessive pressure signs?

Really appreciate, I have searched for a guidance but still will be more happy to hear some result first hand (...and not to brake the lugs )

 

[chromatica]

One of the pressure signs can be an ejector swipe. Its hard to tell this from a static photo. You kind of need to pass the base across a beam of light and look for a shiny spot in the reflection.

 

[mmcu]

It's hard to tell from the pictures, but there appears to be some minor indentation and smearing.

My eyes are not what they used to be and I agree with chromatica that light is your friend.

 

[jelenko]

My take is the primers are 'flatish' and some of the cases do look like they may have ejector smears.
As mentioned, they'd need closer inspection.

 

[mic2377]

You are hot for a bolt gun, and DEFINITELY too hot for an AR. The data you are running is "bolt gun" levels, except in an AR-15. There is different data for each of these.

AR-15's are pressure limited in the 6 ARC/6.5 Grendel due to the case head vs bolt lug dimensions. The larger case head versus a 223 means the lugs are thinner in comparison.

 

[Vava]

Thank you very much ALL for the help! I will definitelly go down with the load.

 

[243winxb]

I reload 6 ARC with LeverEvolution and 103 ELD-X, COAL 2.26" , powder charge 30,2 grain, brass is Starline.

Hornady data for BOLT GUN. Below.

Ask Hornady for auto data.

 

[DHD]

I have a couple of 6ARC AR's (16" and 20" Proof barrels) and either one would run into pressure signs at 29.7 grains of LeverRevolution using 105's. I always use thicker cup primers (Magnum if you will) and Rexus bolts for all the extra safety I can get.

FWIW, I load both of mine no heavier than 29.2 grains of LeverRevolution using 105's.

 

[Webphut]

I have always used a 1" micrometer to measure the case heads. If the heads grow .0005" larger than what they were originally then the pressure is too much. I back the powder charge down until the case head size is back to original size. If the fps deviation or the group size is so tight and I am at .0005" oversize, I might back the charge down .2 or .3 grains. I get a lot of flack for using this method, but its the only way I have ever measured for pressure. I never was able to learn the looking at the primer head method or the witness mark from ejector method.

 

[David Milisock]

Hi all, I am new to reload for AR15. I reload 6 ARC with LeverEvolution and 103 ELD-X, COAL 2.26" , powder charge 30,2 grain, brass is Starline. Can someone more experienced look at the attached pictures to say whether there are any excessive pressure signs?

Really appreciate, I have searched for a guidance but still will be more happy to hear some result first hand (...and not to brake the lugs )

AR pressures are limited to 52,000 PSI, I doubt that you'll see pressure signs in your brass at that level. At you current load pressures you risk excessive wear and bolt failure.

 

[Rob01]

Here is the page with AR data. It’s the 108 weight but gives an idea of charge weight for 103s. Also remember the Starline brass has a smaller internal capacity than the Hornady used in the data below so there will be a smaller internal capacity difference there as well.

 

[cheeseburgerblue1953]

Here is the page with AR data. It’s the 108 weight but gives an idea of charge weight for 103s. Also remember the Starline brass has a smaller internal capacity than the Hornady used in the data below so there will be a smaller internal capacity difference there as well.


View attachment 1720151

My 18" Odin barrel AR won't shoot the 108g with max pressure using LeverEvolution, the base of the cartridge begins to bulge over 28.3g. The max charge is going to give you real problems. Hornady data should be used with caution and increased slowly.

 

[Rob01]

My 18" Odin barrel AR won't shoot the 108g with max pressure using LeverEvolution, the base of the cartridge begins to bulge over 28.3g. The max charge is going to give you real problems. Hornady data should be used with caution and increased slowly.

That’s what anyone should do when loading. Never start with near max. The Hornady info is good but variables in rifles requires everyone to work up to what works in their rifle.