12.5 CMMG out of battery issues

Moderators: gds, bakerjw, renegade

Post Reply
mrblaq2u
New Member
Posts: 5
Joined: Mon Apr 07, 2014 2:52 pm

12.5 CMMG out of battery issues

Post by mrblaq2u » Sat May 24, 2014 12:10 am

Have a quick question...just got around to shooting my custom 300 BO and had out of battery problems with almost every round (all hand loads, 125gr SMK‘s and 150 gr). Wanted to know before I start getting pissed off, should I try some factory loads and see how they chamber? My set up is a CMMG 12.5" barrel, Spikes BCG, Quentin Defense lower, TNW upper. The few rounds I could shoot worked great but could not get all the rounds to chamber fully. If headspace was an issue, would I have been able to get those few shots off? Thanks in advance.

BulletFlight for Android
User avatar
Omega
Silent But Deadly
Posts: 494
Joined: Wed Jan 15, 2014 10:28 am
Location: Clarksville, Tn

Re: 12.5 CMMG out of battery issues

Post by Omega » Sat May 24, 2014 12:22 am

mrblaq2u wrote:Have a quick question...just got around to shooting my custom 300 BO and had out of battery problems with almost every round (all hand loads, 125gr SMK‘s and 150 gr). Wanted to know before I start getting pissed off, should I try some factory loads and see how they chamber? My set up is a CMMG 12.5" barrel, Spikes BCG, Quentin Defense lower, TNW upper. The few rounds I could shoot worked great but could not get all the rounds to chamber fully. If headspace was an issue, would I have been able to get those few shots off? Thanks in advance.
Post your handload coal, and if you noted any marks on the bullet upon extraction. Most of these issues are due to seating depth.
"Freedom is the sure possession of those alone who have the courage to defend it."
~Pericles~

takiniteasy88
Silent But Deadly
Posts: 544
Joined: Sat Apr 26, 2014 6:50 pm
Location: New Mexico

Re: 12.5 CMMG out of battery issues

Post by takiniteasy88 » Sat May 24, 2014 12:51 am

There are so many reasons this could happen. If you have a few factory rounds that would be a good place to start, shoot them and if they run fine you have an ammo issue if they do not shoot you have a rifle problem. If it is ammo the brass might be to thick or it could be the coal. If it is a rifle problem it could be the buffer, buffer spring, gas tube, charging handle. But I would say try to find a few rounds of factory ammo and see what happens, you also may want to change you coal or brass to see what happens.

User avatar
illdill
Silent But Deadly
Posts: 174
Joined: Sun Feb 23, 2014 2:02 am
Location: Idaho
Contact:

Re: 12.5 CMMG out of battery issues

Post by illdill » Sat May 24, 2014 12:59 am

Sheridan gauge. Also, what is the head stamp on the reloaded brass?
The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.
- Thomas Jefferson
That time is fast approaching.

mrblaq2u
New Member
Posts: 5
Joined: Mon Apr 07, 2014 2:52 pm

Re: 12.5 CMMG out of battery issues

Post by mrblaq2u » Sat May 24, 2014 1:36 am

The head stamp is mixed i.e. LC, PMC etc. I bought the ammo from someone and wanted to try it out. Can't do a coal until the tomorrow as someone is borrowing my calipers. Won't have any more results until I pick up a box of factory and try that. I'll post results afterwards. I'm hoping its the ammo and not the rifle.

mrblaq2u
New Member
Posts: 5
Joined: Mon Apr 07, 2014 2:52 pm

Re: 12.5 CMMG out of battery issues

Post by mrblaq2u » Sat May 24, 2014 1:39 am

Also to note, it looks like it might be the ammo because each piece of brass looks as though it was tight in the chamber. Once I figure out how to post pics I'll put some up!

mrblaq2u
New Member
Posts: 5
Joined: Mon Apr 07, 2014 2:52 pm

Re: 12.5 CMMG out of battery issues

Post by mrblaq2u » Sat May 24, 2014 7:13 pm

Okay, here's my update....after posting my dilemma last night, I decided that maybe the chamber was tight because of the finish that CMMG applies to their barrels. So I grabbed a brass chamber brush and gave it a good scrubbing. Took her to the range and bought some factory ammo and shot about ten rounds thru her. Then I grabbed the hand loads and shot about thirty rounds thru the barrel with no hiccup or problems!!! She is all good now! I kept all the brass I went through to use as reference when I decide to start loading myself. Thanks to all who chimed in and have a great Memorial Day weekend!!! Now its time to decide on a can for her..

User avatar
RAINS
Silent But Deadly
Posts: 542
Joined: Mon Sep 30, 2013 6:18 pm

Re: 12.5 CMMG out of battery issues

Post by RAINS » Sat Mar 21, 2015 2:38 pm

CMMG nitrides their barrels. There is nothing to build up on the surface. It's not like chrome lining. Nitro carburizing hardens the surface it's not a coating. Your chamber probably just had some gunk in it or a build up of lube. Could of also had a bur or something else in there. Glad you got her running right.

Nic56
Silent But Deadly
Posts: 323
Joined: Mon Mar 09, 2015 2:28 am
Location: Decatur, AL

Re: 12.5 CMMG out of battery issues

Post by Nic56 » Sat Mar 21, 2015 4:23 pm

takiniteasy88 wrote:If it is ammo the brass might be to thick or it could be the coal.
This is what I would have guessed.

I believed PMC brass is one brand that is not ideal for converting to Blackout.(?) The case thickness is too much leading to excessive dimensions when you load the bullet. I believe the maximum wall thickness is .013". PMC has thicker case walls. I had to scrap some because of that. It might work in a clean chamber, but it will most likely be tight going into battery. A dirty chamber would definitely start showing problems with it. I only use Lake City brass for brass conversion now.

I wouldn't think the COAL would be the culprit. It would probably be very difficult to load 125 and 150 grain bullets too long to cause an issue.
300BLK AR-15 with 10.5" Noveske barrel (1:7 pistol length gas)

300BLK 16" AAC Handi Rifle (1:7 twist)

300BLK 16" AR-15 with 16" PSA FN barrel upper (1:8 pistol length gas)

User avatar
plant.one
Silent But Deadly
Posts: 6695
Joined: Tue Jun 23, 2009 8:31 pm
Location: Oakland County, MI

Re: 12.5 CMMG out of battery issues

Post by plant.one » Sat Mar 21, 2015 5:23 pm

and wow talk about digging up a dinosaur lol.. thread revived almost a year later.

RAINS wrote:CMMG nitrides their barrels.
they still offer non-nitrided stainless. but for their non-stainless yes this is true :)
Reloading info shared is based on experiences w/ my guns. Be safe and work up your loads from published data. Web data may not be accurate/safe.
This disclaimer will self destruct in 10 seconds.

Post Reply