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My 458 socom does a lot of denting. I use it to tell how many times I have reloaded since it’s usually a scratch in the brass.
 

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Or could be to much sizing lube/lube build up.


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While over lube will dent cases the dent will press out upon fireing . What happens is as the case is being extracted it is also being pushed towards the right and hits the side of the upper right after the neck clears the chamber . Cases from bolt action hit things on the way out also just not with as much force .

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While over lube will dent cases the dent will press out upon fireing . What happens is as the case is being extracted it is also being pushed towards the right and hits the side of the upper right after the neck clears the chamber . Cases from bolt action hit things on the way out also just not with as much force .

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Yep. If they come out of the gun like that, what he said. Even Mini 14s will hit the charging handle and do that as "open" as they are.

Out of the die, other than lube, really fine media will stick via static and sometimes cause that. Used small corncob blast media and it did that a lot.
 

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Yep. If they come out of the gun like that, what he said. Even Mini 14s will hit the charging handle and do that as "open" as they are.

Out of the die, other than lube, really fine media will stick via static and sometimes cause that. Used small corncob blast media and it did that a lot.
Adjust your gas volume if its an issue. Those dimples are nothing.

AKs are way over gassed and usually produce a crease. We have a Vepr 308Win that was way over gassed, and more than half of the brass was mangled so badly I would scrap it. The recoil was bad enough enough that I worried the gun was being damaged. Accuracy wasn't very good either. So I shortened the barrel by 4 inches to 19.75" with a Supercomp Brake and installed a KNS adjustable gas piston.

Since I was spending money on it l also installed a recoil absorbing IMI DMR stock. Now the Russian inards are Power Custom so the trigger is sweet, and the safety is a Krebs Enhanced. The piston tube and scope mount are from CSS. Basically because of dented brass I rebuilt it. Now it is all non Russian except for the receiver w/cover, barrel, gas block, and BCG.

The result was the profound. It is now the softest recoiling 308Win we have. The brass barely gets a scratch and is often unmarked, depends. Now you can even see hits.

You won't have to spend that kind of money start with an adjustable gas block we are using Superlatives on our ARs.

@ThELioN70x7 has done quite a bit of work figuring out how to maintain reliability while reducing gas volume and recoil by using light BCGs and playing with spring strength and buffer weight with adjustable gas blocks.

You could avoid the rabbit hole completely and glue some sort of case bumper on your deflector and shoot on. 😉
 

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Yep. If they come out of the gun like that, what he said. Even Mini 14s will hit the charging handle and do that as "open" as they are.

Out of the die, other than lube, really fine media will stick via static and sometimes cause that. Used small corncob blast media and it did that a lot.
My Ruger Ranch Rifle in 6.8 SPC (some call it the mini 6.8) has the same type of dinging, so it is and can be a normal issue.
 
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Discussion Starter · #11 ·
Thanks guys, I wasnt to concerned, never reloaded the 5.56 just shoot and let brass lie. This 6.8 I started reloading and just noticed the dimple and was curious.
 

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That’s a very stiff charge for a 120. Your cycling is off timing. Try 27 gr with a couple loads and see if the dent goes away.

Regardless, I am an advocate for using an adjustable gas block so your cycling can be tuned for any given load, resulting in a nice 3 o’clock ejection.

Also check your bolt for over-travel by pulling your charge handle as far rearward as possible and look through the ejection port to see if your bolt retracts beyond the rear edge of the ejection port. If it does, you will need to add some spacers inside your buffer tube to correct this. The old-school method is using quarters, but 2A Armament makes some nice delrin spacers.

A properly tuned rifle won’t exhibit case dents. However, with a charge that hot, your primer pockets aren’t going to last long anyway.
 

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That’s a very stiff charge for a 120. Your cycling is off timing. Try 27 gr with a couple loads and see if the dent goes away.

Regardless, I am an advocate for using an adjustable gas block so your cycling can be tuned for any given load, resulting in a nice 3 o’clock ejection.

Also check your bolt for over-travel by pulling your charge handle as far rearward as possible and look through the ejection port to see if your bolt retracts beyond the rear edge of the ejection port. If it does, you will need to add some spacers inside your buffer tube to correct this. The old-school method is using quarters, but 2A Armament makes some nice delrin spacers.

A properly tuned rifle won’t exhibit case dents. However, with a charge that hot, your primer pockets aren’t going to last long anyway.
Are you saying a properly timed rifle holds the case straight and doesn't push it towards the opening until the neck has cleared the receiver ? Or are you saying a properly timed rifle moves the case rearward so fast it is past the receiver opening before it has time to hit the side of the receiver ?

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No matter what you do accept the fact semi auto guns are rough on brass . The softer the brass and hotter the load the more it is going to get beat up. As 1 boyouboy noted you are loading hotter than most . Cutting back may make the dents more or less prevelent but I think you are worried about the wrong end of your case . Primer pocket wear would be my main concern as far as the cases go . Also I noticed the case in the picture is shiney and seems to have circular rings on neck . Did you polish it before taking the picture or is that how it came out of the gun ? I would be curious to see what the primer / head looks like also .

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That's a good point @ozarkpugs. Even though it's blatantly obviously now that you point it out, it almost looks as if that neck is scraping against the chamber (being pulled out under pressure) or there's an abnormally tight fit there. I've not seen that on either my 16" ARP 3R barrel nor the current DD 16" 5R on any brass. I've shot Hornady, PPU, Wilson Combat and a few others using starline.
 

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Discussion Starter · #16 ·
No matter what you do accept the fact semi auto guns are rough on brass . The softer the brass and hotter the load the more it is going to get beat up. As 1 boyouboy noted you are loading hotter than most . Cutting back may make the dents more or less prevelent but I think you are worried about the wrong end of your case . Primer pocket wear would be my main concern as far as the cases go . Also I noticed the case in the picture is shiney and seems to have circular rings on neck . Did you polish it before taking the picture or is that how it came out of the gun ? I would be curious to see what the primer / head looks like also .

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Yes this just came out of the tumbler and was cleaned since firing.I was wiping off the brass when I noticed this. I had been doing a ladder test of loads. I do have odin adjustable gas block and loads eject consitently at 3-4 oclock within inches of each other. This is a spcll chamber also.
 

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Yes this just came out of the tumbler and was cleaned since firing.I was wiping off the brass when I noticed this. I had been doing a ladder test of loads. I do have odin adjustable gas block and loads eject consitently at 3-4 oclock within inches of each other. This is a spcll chamber also.
If primers look good and case extracts good and clean keep shooting . Out of curiosity have you measured your bore length . A longer than usual bullet jump may be why you have not ran into problems with your load .

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