chris1977
.40 S&W
Ok I am having an issue with my latest build. Maybe you guys can help me out. I give details in the video but if I missed something ask and I will get the info.
Try describing the problem in type. The 10 seconds of the video I looked at, seems like the bolt is not locking back.
Q: Are you using factory or reloaded ammo?
Both factory and reloads.
Q: Do you have an adjustable gas block?
No I do not.
Q: What size is the gas port in the barrel?
It is .076 on my crappy calipers.
Q: Are you sure the gas block is aligned properly.
There is an even ring along the outer edge showing where the hole on the gas block is and the port hole on the barrel is in the middle of it.
Q: What weight buffer are you running in your lower with the problems?
It is coming in at 3oz exactly.
Are you using a gas block that was made for use with a standard military hand guard end cap? That could make it not line up without it, I think.
Black buffer.
DING DING DING!!!!!
Winner! Buy a new american made buffer. Gold anodized color. I have them. This will solve your problem.
I would agree with you but, since it is doing the same thing on the other lower that uses a rifle buffer and spring I am leaning towards gas issue. That is not a black buffer.
A new buffer was already ordered so no worries there. Just because I wanted a better one. I knew what I had was a cheapo but got a good deal on the setup. Also I am pretty sure I can handle putting a gas block on so no need to ship it out, but thanks for the offer.
You are within the .074-.086 range for mid length, on the low end but in the range. If you are losing any gas pressure (being on the low end) it would result in what you are experiencing. Once you get on the high end of the spectrum you would have over pressure problems. If it were my gun, I would put a Seekins adjustable gas block on it and tune it from there. If you get to wide open on the Seekins and still have cycling issues your problem is either in the buffer system or the gas port not wide enough for your system.Everything I have read, the port size is within the range for that gas length.
no not having the brake would not effect it.So here at the range and have adjusted every which way with both lowers and still doing the same. Could not having a brake or flash hider on and only having a thread protector cause this? I am not buuing that it is the buffer since the first lower I built has a rifle buffer in it and does the same damned thing. Really getting annoyed.
A no name brand adjustable gas block? In your case you probably should have started out with it wide open and worked your way closed in 1/4 turn increments until it stopped locking back.I got one from joebob. I adjusted in 3/4 turn increments.