Put some glitter nail polish on. Will shoot it next week.
It’s for a .750 seat, and the LW barrel has a .625… Oh well.
my 14.5 BCM middy leaks a bit around the sight…i am not worried, just use it.
As was mentioned, aluminum blocks are trouble.
I made one for my m4gery and after 3 mag dumps my gun stopped extracting. Couldn’t see anything wrong, but didn’t have any tools where I was to troubleshoot it either, so I packed it up.
Later, when looking at it after it’d cooled down, I heard a ringing sound when handling the gun - but couldn’t figure out what was making it.
Turned out the aluminum grew faster than my stainless barrel, and walked itself off the port. The ringing was my front grip holder ring dinging around against the gas tube.
Here’s the kicker: the gas block had shrunk (all metal shrinks after it’s heated beyond a given temp), but now it was 1/4" forward of the port and frozen solid on the barrel. :eek: No amount of beating would get that thing to move. Had I known what the problem was in the field, I could’ve moved it back and that block probably would still be on the gun. Instead, I had to mill a slot in it, then split the block to get it to release.
Being somewhat lazy, and having a pinned and welded muzzle brake on the barrel - I moved it back into position and tigged the slot closed. That worked fine for another year before I decided I should really replace that ugly thing with something else.
The port was also heavily eroded from probably 800 rounds use. Not something that was going to improve with carbon build up. I won’t be using aluminum ever again. It’s simply not a good material for the application.
I think syrac is steel.
I would pull the gas block and measure the barrel to be sure it’s in spec. Once you’ve identified the gas block as being out of spec, send it in for replacement.
Did you dimple the barrel for the set screws when you installed the SYRAC? And how about loc-tite on the set screws?
Update to answer a few questions.
I loosened the gas block and it is a tight fit around the barrel.
It is not dimpled
I re-tightened it to where it sits at the shoulder of the barrel instead of 1mm forward of it.
I put some nail polish around it, gonna go to another class on Fri/Sat so we will see any thing is different.
I will not be shoot much nato this time though. The 1000 rds was almost 90% Fed m193
If you have the set screw version (like I do), it is HIGHLY recommended that you dimple the barrel so that the set screws have a place to hold on to…it is actually in the instructions IIRC.
And don’t forget the loc-tite…I used blue, maybe should have used red…but oh well. I’ve also heard to use rockset.
This is likely the cause of your problems.
Question for you…
My SYRAC was loose as well when sliding it on to the gas journal (part of barrel that has the gas port drilled). Did you find that yours shrunk down after getting it heated up like a previous poster mentioned? It’s the first I’d heard of that, so I’m curious.
I used rockset the first time but it was old so it still came loose. I used some new red this time. Im not sure if it shank. It does feel tighter than when I first put it on. However that could be cause by carbon.
When you pulled it off, could you see where the gas was blowing by?