Modern Sporter - Build Discussions

[juancarlos]

I built it with the following parts
Faxon 18.6” Gunner .223 Wylde rifle length gas
Faxon .625” low pro gas block
Faxon G2 15” handguard
Ergo enhanced lpk
Bcm pnt trigger assembly
Used the following parts from a brand new m&p:
Buffer tube
Spring
Buffer
Bcg

The issue I was having is the bolt seems excessively tight in the carrier. Every couple round I would get a strange “twang” sound in the buffer, and there would be a round jammed under the bolt and gouged along the casing. I dumped a rediculous amount of oil into it and got the last 20 off without a hiccup. Tried Winchester 55gr bulk and hornady black 62gr. Ejection is consistently around the 3-4 position. I ran it wet to begin with, and have cleaned it, but when inserting the bolt into the carrier there still feels to be excessive force required to move it, almost like it snaps into place.

You need to isolate the problem. If you can borrow another, try changing out the BCG first and see if that works. What weight Buffer are you running?

[jmb9046]

I won’t have access to another bcg for a week or two, and was hoping to take advantage of a sale this weekend lol I’m not sure of the buffer weight, came out of a S&W m&p 15 so carbine weight I suppose? I’m relatively new to this side of things that go pew

[griffin86]

What does your brass look like? Is the rim have case head swipe and extractor marks? Do you have a slickside or FA upper?

[jmb9046]

There’s extractor marks on the rim, and there’s 2 small scratches at the neck about 3/16” apart in line with the extractor marks
And it’s a FA upper

[griffin86]

There’s extractor marks on the rim, and there’s 2 small scratches at the neck about 3/16” apart in line with the extractor marks
And it’s a FA upper

My guess is it’s probably overgassed.

I would try a heavier buffer first. I would check to see what you had, maybe try an H2.

[wolfenrun]

Which third party trigger do people recommend? I'm looking at either a Geissele Super 3 gun or some sort of Timney trigger. Cheers.

[DILLIGAF]

Ssa-e

[jiffx2781]

...

[rommelrommel]

I really like the super 3 gun for that kind of stuff, in close, shooting quick, etc but I think the SSA/SSA-E suits the 18.6+ barreled rifle more.

[scottcullen]

Brownells has the Geissele G2S -E which is identical to the ssa-e just doesn’t have the laser markings on it. It’s a brownells exclusive and I got mine for like $139 on sale.