Mega Arms Barrel & Seekins Gas Block Install

[sentry1]

It has arrived! Took a stroke of luck, but a Hide member mentioned he saw these in stock and I snagged one just as they were down to 3 left.

http://megaarms.com/maten/maten-barrels/new-barrel/

20", 1:10 twist, rifle length gas system, medium contour, .750 at the gas block, 5/8-24 threaded with a 11 degree target crown, & guaranteed sub-MOA with match ammo.

On to the fun stuff. Stripped out the old barrel (a DPMS AP4 barrel that shot around 1 MOA with match ammo @ 200 yds, probably more limited by me than anything else), and got the Seekins adjustable gas block installed.

On a side note, the roll pin opening on the Seekins gas block is flat, not chamfered for ease of insertion like other gas blocks. After a lot of swearing and multiple hunts for the roll pin across the carpet, I just took a drill bit and chamfered one side of the hole, then hammered that fucking pin in.

On to my next woe: The medium contour behind the gas block seat makes it damn hard to adjust the brass tension screw on the Seekins gas block. I'm definitely wishing I'd waited on the Wilson Combat gas block, which features a front adjust mechanism.

At some point during the week I'll run this over to the local shop and have the AAC 51T brake mounted and timed.


For now, I just cleaned the barrel out. There was a good bit of gunk in there! I ran a few wet patches soaked with solvent, then used a nylon bore brush for a little scrubbing, and here are the 5 patches it took to get it fairly clean.

 

[sentry1]

Coming Soon: Range Report!

 

[cjlane]

tagged for results!

 

[Name Enough]

At some point during the week I'll run this over to the local shop and have the AAC 51T brake mounted and timed.

AAC 51T timed??? I have installed them myself and was not aware that they were to be timed. Please help me out and explain the timing of this brake.
thanks
Ray

 

[sentry1]

Are you thinking of the flash hider, not the muzzle brake?

 

[Ravenyzf-r6]

Eagerly awaiting range report. How are these barrels compared to Bartlein or Lilja barrels? I have a MKM set and I am shopping Thanks

 

[sentry1]

They're referred to as match grade barrels. I've heard it speculated that one of the reputable barrel makers produces these for Mega, but haven't seen any evidence to confirm that. I'm going to shoot some LC M80 147gr through it, some LC M118LR, and some hand loaded 178 AMAXs in Black Hills Match brass.

The real results will come once I have some brass fired from the new barrel, so I can make a fine tuned load.

 

[cjlane]

so how did the barrel shoot?

 

[sentry1]

Haven't been able to break it in yet. I had to drop it off at the gunsmith, since I didn't have the spacers to time the muzzle brake myself. He was supposed to have had it done in time for me to shoot this weekend, but no such luck. I'm hoping he'll have it for me early this week.

Edit: He got it back to me today. Going to get out to the range ASAP.

 

[Carphunter]

Any reports on this? How did it do?

 

[sentry1]

I posted the update somewhere else along with some other problems I ran into. Long story short, at 200 yards I had good groups with all sorts of ammo.

147gr ball ammo, unsurprisingly, was the loosest grouping at about 1.5 MOA, M118LR and 175gr SMK handloads (handloads a friend had made for his boltgun, I compared headspace and fired a few, no problems) had similar size groups at just under 1 MOA.

Caveat: This is my first .308 gas gun, so I make no guarantees as to what this setup can actually achieve with a better shooter.