User Panel
User Panel
User Panel
|
Posted: 3/6/2024 12:35:03 PM EDT
I posted this in GD, but someone recommended I post it here too (didn't realize there is a KAC forum).
I had a couple blown primers with quality ammo (IMI 69gr HPBT Match SMK OTM Razor Core) in my SR-15 Mod 2. I stopped using the rifle the rest of the day. I had used the same batch of ammo in 2 other ARs that day without issue. After inspecting it I found that one of the gas rings had sheared a bit and would not hold the weight of the carrier. Obviously I swapped on new rings. All that said would the inappropriate gassing cause the blown primers? If yes, what else do I need to inspect for damage before using again? Or am I completely off base and need education on what happened?  Attached File Attached File Attached File Attached File |
|
|
|
|
Posted: 3/6/2024 12:51:08 PM EDT
[#1]
My 16" SR15 hates powerful loads like 77gr.
I sent it in to KAC and they said the following:  I also saw two other SR15s punch primers with Black Hills 77gr at competition |
|
|
|
|
Posted: 3/6/2024 1:53:44 PM EDT
[#2]
Quote HistoryOriginally Posted By WhiskersTheCat: My 16" SR15 hates powerful loads like 77gr. I sent it in to KAC and they said the following: https://www.ar15.com/media/mediaFiles/425212/Screenshot_20240306_115033_Gmail-3150972.jpg I also saw two other SR15s punch primers with Black Hills 77gr at competition @WhiskersTheCat Thank you. I just ordered a go/no-go headspace kit. I'm going to see what that tells me before I go to KAC. Much obliged. p.s. since I have your attention, just thought you would like to know I now own 3 Staccatos and an Atlas Titan RDS because you talked about how 2011's make you a better shooter. I are correct, lol. |
|
|
|
|
Posted: 3/6/2024 2:07:50 PM EDT
[#3]
That looks more like a dropped primer then a blown primer to me, as in I don't see primer pocket expansion, at least from what I can see from my phone...
If it isn't expanding, try and compare similar loads with crimped versus non crimped primer pockets. |
|
|
|
|
Posted: 3/6/2024 2:18:42 PM EDT
[#4]
Quote HistoryOriginally Posted By NorCalRT: That looks more like a dropped primer then a blown primer to me, as in I don't see primer pocket expansion, at least from what I can see from my phone... If it isn't expanding, try and compare similar loads with crimped versus non crimped primer pockets. I've never heard of a dropped primer. I'll do some research. |
|
|
|
|
Posted: 3/6/2024 2:36:18 PM EDT
[#5]
Quote HistoryOriginally Posted By HBIII: I've never heard of a dropped primer. I'll do some research. Quote HistoryOriginally Posted By HBIII: Originally Posted By NorCalRT: That looks more like a dropped primer then a blown primer to me, as in I don't see primer pocket expansion, at least from what I can see from my phone... If it isn't expanding, try and compare similar loads with crimped versus non crimped primer pockets. I've never heard of a dropped primer. I'll do some research. Black Hills uses the term, see if the primer fits back in the pocket, that will tell you real quick. It's long been accepted that a primer popping out of a case when a round is fired is an absolute indication of high pressure. This is usually referred to as "blown" primer. However, it can also occur because a gas-operated, semi-automatic rifle is not properly timed. In other words, the bolt unlocks before the case releases its hold on the chamber, and the primer pops out. |
|
|
|
|
Posted: 3/6/2024 2:40:58 PM EDT
[#6]
Quote HistoryOriginally Posted By NorCalRT: Black Hills uses the term, see if the primer fits back in the pocket, that will tell you real quick. So the sheared gas ring could have caused it? |
|
|
|
FL, USA
|
Posted: 3/6/2024 3:22:52 PM EDT
[#7]
"Dropped primer" is the term used for that. Punching/piercing a primer is something different.
It's not a headspace issue, as that has pretty much nothing to do with anything that would cause a dropped primer. Leading cause of dropped primers is high pressure with insufficient staking of the primer. KAC uses a 5.56 NATO chamber and throat. It is possible for carbon and copper fouling in the throat to increase pressure and contribute to dropped primers. |
|
|
FL, USA
|
Posted: 3/6/2024 3:28:30 PM EDT
[#8]
Test some different ammo in the SR-15 and see if it is stripping/popping the primers. If it is only happening with the one load, then it's probably not the gun. If it happens with all of them, then it might be the gun.
Trial and error is really all you can do to troubleshoot without a more thorough evaluation. To be fair, it could happen on that one load only AND be the fault of the gun - but yeah, trial and error for now. |
|
|
|
Posted: 3/6/2024 4:38:36 PM EDT
[#9]
Quote HistoryOriginally Posted By HBIII: @WhiskersTheCat Thank you. I just ordered a go/no-go headspace kit. I'm going to see what that tells me before I go to KAC. Much obliged. p.s. since I have your attention, just thought you would like to know I now own 3 Staccatos and an Atlas Titan RDS because you talked about how 2011's make you a better shooter. I are correct, lol. 2011s are just cheating |
|
|
|
|
Posted: 3/6/2024 4:39:34 PM EDT
[#10]
Quote HistoryOriginally Posted By Jack_L: "Dropped primer" is the term used for that. Punching/piercing a primer is something different. It's not a headspace issue, as that has pretty much nothing to do with anything that would cause a dropped primer. Leading cause of dropped primers is high pressure with insufficient staking of the primer. KAC uses a 5.56 NATO chamber and throat. It is possible for carbon and copper fouling in the throat to increase pressure and contribute to dropped primers. This is who you want to listen to, OP |
|
|
|
VA, USA
|
Posted: 3/7/2024 12:24:51 AM EDT
[#11]
Have had something happen with my cqb mod 1, but with admittedly shitty zsr ammo. Also had an apparent issue where something like a mini oob detonation happened. Noticed nothing really different during shooting, but noticed one of my cases was bulged towards the back of the case along with a blown-out primer.
|
|
|
|
Posted: 3/7/2024 9:43:25 AM EDT
[#12]
Had that happen with a lot of CBC 77.
CBC replaced it due to it being a known issue. |
|
|
|
|
Posted: 3/7/2024 1:14:02 PM EDT
[#13]
Quote HistoryOriginally Posted By WhiskersTheCat: This is who you want to listen to, OP Quote HistoryOriginally Posted By WhiskersTheCat: Originally Posted By Jack_L: "Dropped primer" is the term used for that. Punching/piercing a primer is something different. It's not a headspace issue, as that has pretty much nothing to do with anything that would cause a dropped primer. Leading cause of dropped primers is high pressure with insufficient staking of the primer. KAC uses a 5.56 NATO chamber and throat. It is possible for carbon and copper fouling in the throat to increase pressure and contribute to dropped primers. This is who you want to listen to, OP I had been leaning toward it being ammo related. I'll give the chamber and throat a good cleaning to remove that possibility. |
|
|
|
|
Posted: 3/11/2024 6:37:30 PM EDT
[#14]
Passed the go / no-go gauges...
|
|
|
|
|
Posted: 3/12/2024 4:08:32 PM EDT
[Last Edit: coal-cracker]
[#15]
Had similar occurrence with AAC 77gr.
Contacted PSA and returned the ammo. I heard similar reports from other users. Bad batch maybe? No issues with Razorcore 77gr through over 1000 rounds. No issues with any other ammo. |
|
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
