Look at these!

[George]

Ok guys I loaded some 300blk out and got my cycling issues straight(gas block was not flush and hand to get rid of handguard cap) I shot about 8 rds of my loads (17gr h110 lc and fed brass trimmed to 1.360 seated and crimped lightly 125gr Sierra mk.

Look at the pics and you can see there are flat spots on the top of the mouth. I believe this is being caused by the ejection of the brass because if you look at the pic of the brass deflector you can see how hard the spent brass is hitting it. Now this brings me to the buffer. I think the buffer might be too light (3oz) because it is slinging the brass so hard plus when it locks the bcg back it hits pretty hard. Let me know what yall think.

Sent from my SAMSUNG-SGH-I727 using Tapatalk 4

 

[noylj]

Your analysis is probably correct--or an extractor/ejector problem.
If the buffer is the same as for .223, then it almost certainly is too weak.

 

[NIGHTRODDER07]

are u using an adjustible gas block or shooting suppresed?

 

[George]

Nope

Sent from the bunker.

 

[jgreco15]

The dents you see in the case mouth a perfectly normal!!! This is from the mouth of the case hitting the shell defelctor. The dents are easily popped out when resizing. Some have worried that the continual denting and dent removal will work harden the brass in that area causing it to become brittle but I have put brass through 6 firings without a problem. Nothing at all to worry about, keep shooting!

ETA: Some people have also tried to create a "fix" to this problem that doesn't exist by putting a square of velcro (soft side) on the deflector. I just pop the dent out when resizing and go about my business unworried.

 

[George]

Yes I know. Ive just gone with the soft sided velcro on the deflector. Going to test it today

Sent from the bunker.

 

[Emperor]

Your gun is performing normally. My SIG 516 shell deflector is almost completely scarred to bare metal. Hell, those spent cartridges come out of it so fast and hard, I am actually shooting twice each shot!

Sig told me that is exactly how it is intended.

 

[George]

Thats about right. The bokt is moving pretty quuckly

Sent from the bunker.

 

[George]

And im on the low end of powder

Sent from the bunker.

 

[asianpersuasion]

Adjustable gas block for the mfw

 

[George]

Dont need one with a 16" barrel.

Sent from the bunker.

 

[gunner_lee]

I had to install a tuneable gas block to get my subsonics w/ suppressor to function realiably as well as the supersonics with my 18" bbl. I just had to find the tuned "sweet spot" so that both loads cycled the action and locked the bolt open on last round. The brass is fine- just resize it as stated.

 

[George]

Hats cause you used a 18" barrel the length on the gas hole is longer

Sent from the bunker.

 

[lickx]

ouch

 

[George]

Put on some soft sided Velcro on the brass deflector and that issue is gone

Sent from the bunker.