new 300 WTF

[ds762]

I have been acquiring parts to build another upper. Finally got it together a couple weeks back and since the forum is back up I figured I'd throw out a little eye candy!

Parts are:
a3 upper
RRA chrome BCG
Troy TRX HG
Pac-Nor bbl
Badger Ordnance lo pro GB
Nikon M223 1-4
Burris PEPR
SAS 30 cal suppressor
F1 SBR recvr
MagPul CTR

[ds762]

I do have a quick question. When I finally got over to my brother's to machine the barrel .. his DINOSAUR CNC mill that he used to drill it had too much run out and instead of having a gas port of .118 I ended up at .125.

Any foreseeable problems with the larger gas port?

[sha-ul]

While I am not an expert on ar- gas systems, I don't think there would be any problems that could not be resolved with an adjustable gas block, or adjustable tube.

[ds762]

thing is most adjustable blocks (tp555 design) don't jive well with handguards (at least in my experiance - LaRue and Troy TRX).

The gun cycles supers suppressed and unsuppressed .. now I just need to get some more projectiles and load up some subs and see how it goes.

[sha-ul]

what about the gas tubes with the allen screw adjuster?

http://www.brownells.com/.aspx/pid=9...LATED-GAS-TUBE

[dick]

I have tried the adjustable gas tube, you may have to relocate the valve that requires another gas tube. In my experience the valve will start to loosen up after a while. I would take a look at JP or PRI for an adjustable low profile gas block. You may need to modify your hand gaurd to access the adjustment screw, hand drill a small hole or open up with a dremmel tool, if real tools are not availible.

[ds762]

loaded up some subs .. gun cycles fine. switched back to supers and I noticed a considerable more amount of recoil. overgassed?

took the BCG apart and the cam pin exhibits some wear (only shot 100-200 rds of supers before today) ... sign of overgassed?

talked to a couple friends and they suggested a heavier buffer. will this in and of itself help cure an overgassed gun??

looking for an easy fix here. short of that I may have to get a new barrel as I don't want to beat the gun up with it cycling to harsh.

[dick]

ds762 You have different options, heavier buffer, carrier weight, hydraulic buffer, adjustable gas block. An adjustable gas block would fix your over gassing problem. I have a 300/221 16" with pistol gas system opened to .120 I only run subs with a Enedine hydraulic carbine buffer to slow the action. You would have to experiment with weights and heavy buffers, to find the right combo, and still be able to run your sub loads. The cam pin wear is normal, just keep it lubed, I like Tetra lube, good stuff in AR's.

[ds762]

[QUOTE=dick;36147]
The cam pin wear is normal, just keep it lubedQUOTE]

I guess I mis worded this .. the cam pin has a groove cut into it that will stop a fingernail when run across. I've shot quite a few AR's and never had this before.

due to most adjustable gas blocks having issues going under railed handguards my options are limited. Know of a gunsmith that will drill out and tap my Badger lo pro to turn it into an adjustable?

[dick]

I doubt the gas block that you have has enough material to do so. The JP and PRI blocks have a little extra where the adjustment screw penatrates the block.