Mega Arms MATEN MKM w/ Mega match barrel range report

[sentry1]

Hardware:

• Mega Arms MATEN MKM receiver set
• Mega Arms .308 barrel, 20", 1:10 twist, rifle length gas system
• JP BCG w/ enhanced bolt
• Seekins adjustable gas block
• Geissele SSA-E trigger
• Magpul CTR stock
• Battleline SAPR
• ADM Recon 34mm mount
• AAC 51T muzzle brake
• Atlas bipod
• Bushnell ERS 3.5-21x50 G2 reticle

Ammo

• M80 147gr ball, LC brass
• M118LR 175gr SMK, LC LR brass
• Handloads, 178gr AMAX, Black Hills match brass, CCI BR primer, 42.4gr of H4895
  (these were loaded by a friend for his bolt action, so they're not tweaked to perform for the MATEN)

All shots were taken at 100 yards, from the bench with the Atlas bipod and a rear bag. 91 degrees outside, heat index of 105. Day started off poorly, turns out I somehow lost the tensioning screw on the SAPR, so I couldn't get a proper cheekweld. Then it turns out the gas block wasn't pushing enough gas to fully cycle the bolt (even fully open). It would eject the spent case, but not chamber the next one. So I had to take the damn thing apart (thankfully I had some tools in my range bag) and adjust the gas block placement.

Anyway, barrel round count prior to this firing was 0. I took 2 rounds to zero the scope, and put some more through it in the process of getting the gas system running, so I guess the barrel isn't technically broken in yet. Keep in mind, I'm not a seasoned shooter, and the SAPR stock was flopping around, so the group sizes are more representative of my fingerfucking than the final performance of the barrel.

I'll get everything fixed up, put some more rounds through it, and try some handloads tweaked just for this gun, and update.

 

[kvwpwr]

Be careful shooting some one else's hand loads in your rifle. Especially of they were developed for a bolt gun. Bolt guns can typically be loaded hotter than a semi. Also, its possible they are only neck sized or the should hasn't been bumped back enough.

Nice looking rifle though. I have a maten in 6.5 creedmoor but I wish the mkm was available when I built it.

 

[sentry1]

Too late now! The rounds have been fired, and fortunately, I have not blown my face off.

Funny story: Last year, the first time I shot my own reloads, I did it with my head down, wearing a Kevlar helmet and flak jacket. Y'know... just in case.

 

[biner626]

Sentry, I put my first rounds through mine today. I swapped my 2.5-10 from my .223 AR on the MATEN dialed for 800 and damn if it wasn't POA within .2 MILS. Happy camper. I was cheap and went with the Rainier "select" barrel.
ETA: Is yours beating the crap out of your brass?

 

[sentry1]

No, but I have an adjustable gas block, and I cut the ejector spring down by 2 coils, so it chucks the brass out rather gently, relative to a typical setup.

 

[biner626]

I'm kinda reluctant to cut coils. I may try that DA7 gas block.

 

[sentry1]

Replacement ejector springs are pretty cheap if you take off too much.

 

[problemchild]

Let the barrel "season" with some copper. I would try this load........

42grs XBR, Benchrest primer and a 155gr hornady match projectile.

 

[sentry1]

I'm going to break it in with Varget, CCI primers, and 147gr FMJ bullets. Can't be picky nowadays!

 

[cjlane]

Anyone else have experience with these barrels? I picked one up but I am debating forking up the cash for a JP supermatch with matched bolt or a Lilja

 

[InTheHills]

Sentry - Is that the extended length upper?

 

[sentry1]

Yup, it sure is.

 

[LawnMM]

Where did you buy the mega barrel?

 

[mavrick10_2000]

I'm kinda reluctant to cut coils. I may try that DA7 gas block.

The one I have works well.

 

[sentry1]

Where did you buy the mega barrel?

I don't remember. Someone on the Hide mentioned they found a place with them in stock. They only had 3 left when I placed my order, I got very lucky sourcing these parts.

 

[LawnMM]

The image links are broken, what kind of accuracy have you managed from the mega arms barrel?

 

[cjlane]

The image links are broken, what kind of accuracy have you managed from the mega arms barrel?

I have a similar set up to sentry1's with a 20" mega barrel. I am getting little over 1-2 moa. I am new to shooting and am pretty sure the gun is more capable than that. I have had groups under 1moa when I am doing everything perfectly.

 

[sentry1]

With 147gr FMJs, mine will shoot 1 MOA groups. I didn't measure exactly, but out of a 4 round group, 3 holes were all touching, and the 4th was a little bit off.

I haven't taken out the 175gr match ammo yet, will post new updates after my next range trip.

 

[biner626]

I'm reconsidering cutting coils from the ejector. I was having major issues last time out. My brass was being slammed into the barrel extension causing a lot of brass damage and FTE.
I went ahead and ordered the adjustable gas block and will try that first. Then cut coils.