Anyone had any issues with running Barnes Bolt Carrier Groups in their m4s? I had one new BCG that I took to the range and fired approx 300 rnds of 5.56 LC Grn tip that broke a bolt lug off. I sent it to Barnes and the owner called me and apoligised and sent me a new one. Nice guy but Ive been having issues with these BCGs. I assembled an upper with a Barnes SS barrel and BCG and have constant failure to ejects and stuck brass (really stuck). Another build that I have with a DD .625 and a Barnes BCG that has the same issues. I switch the BCGs out and no worries. Anyone else had these issues or is it just me? All rifles are running free floating handguards and LP gas blocks (.750 & .625). ALL BCGs are 5.56 auto.
Barnes Precision Manufacturing BCGs
- Thread starter Macleod212
- Start date
I would question if they are to light? Have you tried a heavier buffer? In my experience stuck cases are a sign of the bolt opening to soon and the chamber still having pressure holding the case to the chamber walls. This is normally an overgassed situation and adding mass to the BCG or Buffer usually helps. But if the gun works fine with other BCG then it would make me wonder if the Barnes are to light.
An adjustable gas block would be a better solution to this, if it is the problem. Why add more mass to the carrier if the real issue is how much gas is coming through the gas block.
The gas blocks are aligned properly (I predrill the holes for the bottom set screws). Not certain the gas is the issue though. Other BCGs seem to do just fine. I'm just going to have to flog the Barnes BCGs I suppose. Their rifles have a pretty good reputation but I've been having issues with their BCGs.
Havent really tried the heavier buffer. One of the stocks is a PRS so it uses a standard rifle buffer, the others are carbine H buffers.
Not really a matter of the port being properly aligned even though that is for sure needed. The adjustable gas block allows you to remove gas pressure and volume from the operating system. If the rifle is overgassed it can cause all sorts of issues. If the gun runs properly with other bolt carriers then I would imagine there is a design/manufacturing issue with that Barnes BCG.
For one most adjustables are just plain ugly (my opinion, Noveske is nice) and it is always a balance between gas vs mass so adjusting either one will get the same results.
Agreed, there is somthing wrong with said BCG, either they are too light, maybe they are a fraction shorter allowing the bolt to unlock a fraction of a second sooner. Either way they would seem out of spec in one way or another.
Not quite correct, If you add more mass to the bolt carrier group you have more reciprocating mass in the weapon and that will cause additional felt recoil.
Gun will still function the same, gas volume and buffer/BCG mass always have to be matched. Will a heavier buffer add "felt" recoil, sure. It also makes the gun weigh more just packing it around. Fine I give you all that, But the OP original problem was reliable operation that is what he is after. Once the gun runs 100% then he can worry about "felt" recoil.
