Hello. I have been looking here and on ar15.com for about 2 years. I am not much of a forum guy anymore, but they are good sources of information. I have built 4 AR’s and none of them have had any trouble. This is my first post though, and I think I am making it a good one.:fie::fie::fie:
My father has a KAC SR-15 match. He had the muzzle threaded and recently got a Gemtech G5 with a quickmount.
He has been running it without the can for quite some time and has never had a problem with it. Since he has installed the G5 there is a bit of a problem.
He will shoot it a few times and let it rest. At this point if you try to remove the unfired round in the chamber it gets stuck to the point that when you do get it out the bullet head remains lodged in the throat and you literally pull the casing off it.
I removed the barrel and placed a round in the chamber and seems to fit fine with no binding. I removed the gas block and mesured the gas port (.091) and the gas key mushroom is a little worn on one side, like it was mis aligned. Sweets 7.62 cleaned the chamber and was then liberal with the miltech. I greased the bolt and carrier and hand cycled a complete magazine through it cold with no problems. None of the rounds bound up. I cycled Lake City M855, but he is using hand loads that a gunsmith friend of ours made up.
I had them install the G5 on an old colt ar 15 they had and it cycled fine.
I know that the information is incomplete, but I am trouble shooting this via text. They are bringing all the stuff down to me tomorrow, but I wanted to see if you guys had anything I might have missed.
I am going to try it on my new 20" rifle length franken gun with an A2stock similar to the SR-15 in set up and my 16" mid length.
I would contact KAC and see if they have any ideas first.
I wouldn’t function test a weapon with handloads that someone “made up”.
My first thought is that his handloads may have a long overall length and poor neck tension, and the additional fouling from the suppressor is making it an issue.
The rifle functions with no problem without the suppressor. I have yet to get a hold of it and the suppressor and rounds to check OAL and such. I will have to verify all that tomorrow.
These are not loads that were assembled out of hat, but made for the rifle.
Do not use handloads. Also, I would be willing to be that if you have a baffle strike and you tell then handloads were involved your warranty will probably be voided.
Also, there is no need to use grease. Get some Froglube or Slip2000 and lube it so it is wet.
To check for gas key misalignment, you need to disassemble the BCG, take the carrier only and slowly feed it into the upper. If you feel binding as the carrier meets the tube, then the tube is slightly out of alignment or the carrier key is slightly off. You should be able to look at the tube and eye fuck it for alignment.
First off what bullet is in these reloads? It sounds like others have stated they are a little long on OAL. And coupled with a dirty chamber and hotter gun due to the suppressor and a poor or no crimp and you are getting the bullet to pull out and its dumping the powder into your lower. But if the bullets fit and function in the magazine they can not be too far off.
I have not read up on Knights Armament and also wonder about the chamber size if it is a true 5.56 or something tighter for their match guns? The bullet should not be pressing into the leade of the barrel to the point that it could even pull the bullet out. And a properly crimped bullet with a cannelure should never pull out of the case. The free bore or leade before the rifling is very short or the ogive is unusual on the bullets and is a very heavy bullet.
I would quit using the reloads and clean the chamber with a good brush, and use some ammo of know quality. I think that will take care of any problems you are having, but first could you post what bullet you have in your reloads?
And did I miss something what would make you think their was a baffle strike Iraqqunz?
A-max bullets. No baffle strike, since that is the first rifle the suppressor was attached to and no one said anything about a baffle strike. The rifle is an older one. The bullets fit and feed correctly from the magazine. I was wondering about the chamber also. I will have to see about the OAL like I said. I think that you might be right with that, need to try it with M855 or XM193. The A-maxes don’t have a cannelure.
I used Wilson Combat grease. It looks like a really thick oil more than a grease. Seems to be really nice.
I checked the alignment. The BCG drops in nicely. Better no that there is some lubrication.
