Modern Sporter - Build Discussions

[Shorerider]

the Bev block does lock in into the extension;
Will any Barrel Torque tool and vice block work with these receivers?
Will the Magpul Bev block work with these receivers?

Thanks

Barrel torque rods work. The Bev block does work but needs to be modified since the location of the front pivot pin isn’t in the same location as an AR pivot pin.

[Sluggo_m14]

Thanks!- what about "standard" vice blocks like the Brownell's version?

[alberta tactical rifle]

Thanks!- what about "standard" vice blocks like the Brownell's version?

Use a reaction rod, better tool for the job and works with all AR and AR style uppers.

[K9CEL]

Or just clamp the barrel between 2x4 in a vise with leather strip to make sure you don’t damage the finish. I was going to buy a reaction rod but 150$ for a one time tool is too much.

[impactthunder]

...

[Sluggo_m14]

Great-thanks alot for the help!

[Philosoraptor]

I've heard the Midwest Industries Upper Rod is the cock for dolly. Too bad they haven't been in stock for awhile now.

[auracle]

What's happening is the bolt doesn't travel far enough past the bolt catch to allow the bolt catch enough time to come up and engage the front of the bolt. Instead it gets caught on the front of the carrier.

When I put a rifle length buffer tube on one of my second batch lowers I ran into the same "issue". They shortened the rear of the receiver so that rifle length tubes would catch the buffer retainer pin. I noticed right away that the bolt only went past the bolt catch by a little bit and figured this could be problematic. Before I even fired it I shortened the rear of the buffer pad by a good 1/8" to regain some of the lost bolt travel. The rifle works perfect.

Basically everything at the rear of the MS lower is moved forward the same distance as what the bcg sticks out the rear of the upper receiver. So yes, depending on what receiver extension you use the bcg isn't going to travel rewards as far in comparison to what it would on an AR.

So this only happens with a rifle buffer tube? If you are using a carbine buffer tube this shouldnt happen? Is there anyway to test if you have enough bcg travel without shooting it? Thanks

[Betty-Lou]

So this only happens with a rifle buffer tube? If you are using a carbine buffer tube this shouldnt happen? Is there anyway to test if you have enough bcg travel without shooting it? Thanks

It's the same for carbine length. You can pull the charging handle back and check that the bolt face clears the catch but this is no guarantee that it will catch on the bolt face when fired. I swapped out the buffer spring on his gun and that was all that was need for the rifle to function correctly.

We did trim back a buffer, which also worked but he didn't want to have the MS using a "special" buffer.

[Rayf01]

With the talk regarding buffer tube length and cycling, am I going to run in to an issue using a standard mil spec tube, buffer and spring? I was trying to budget a little less and found a set from True North, but want to make sure it will work. Unless I need to go with the PWS tub which is substantially more.