Larry Vickers and the Centurion Arms SPR

[Ekie]

Has anyone gotten a MK12 barrel from Monty lately? I have not heard anything for awhile.

[nickh46]

I've been on the waiting list for a Mark 12 upper since April. Monty let me know that some parts are still coming in, and it should be ready beginning of November.

[Sam]

Has anyone gotten a MK12 barrel from Monty lately? I have not heard anything for awhile.

About 6 weeks ago I had exchanged emails with Monty to get a barrel. He said he was expecting some in. After being on his waiting list for a week, I found a Douglas barrel elsewhere and thus cancelled my order from Monty.

[Cuda444]

Has anyone gotten a MK12 barrel from Monty lately? I have not heard anything for awhile.

I had an email exchange with Monty the other day. I ended up putting myself on the back order list for a barrel. He didn't give an ETA. Worth the wait, though!

[texas12]

I exchanged some emails with Monty and he said it would be a few months wait on the mk12 barrel. Let the waiting begin

[grinch]

I am getting ready to put a batch out now so if your on the list already you maybe getting it soon if you are ordering now it will take me a few months to get the next batch of barrels.

Thanks
Monty

[GMZ]

Damn these look great, and here I thought I didnt want an SPR anymore. Small world I used to live down the street next to the Crown Inn & Bistro.

[Polizei]

What kind of groups with lighter (55 grain ball) rounds?

[grinch]

It all depends on the ammo and the quality of the bullets. The chamber is set up for the Sierra Match King ogive and the lightest MK bullet in 5.56 is the 69gr. Now, that is not to say that your 55gr won't shoot sub-MOA, it's just not optimized for it. Odds are, if it's quality ammo, it will run well through the upper and shoot sub-MOA. The fact that the upper has a 1/7 twist is also not an issue. I've heard lots of people say it "over-stabilizes" the bullet, but I've yet to see a bullet be "too stable". The issue would be that spinning a bullet faster could cause more "wobble" due to any minute differences in copper jacket thickness. This is why it goes back to the quality of the bullet itself since when using a quality bullet this is just a phenomena we don't see especially at the effective ranges this weapon is used at. There is absolutely no downside to having a 1/7 twist barrel on 5.56 platform. It is simply the most versatile twist rate to have and allows you to shoot all available ammo with the overall best results.

Currently, there is a lot of research and work being done in the long range field of shooting that is using faster twist rates than recommended for the bullets they are using and they are not seeing any degradation in accuracy. We are coming to the conclusion that the greenhill formula is a bit dated to an era where the bullet construction was not what it is today. There are guys shooting amazing groups out to 1500-1600 yards with barrels that have way too fast of a twist rate according to greenhill.

Thanks
Monty

[sjopling]

It all depends on the ammo and the quality of the bullets. The chamber is set up for the Sierra Match King ogive and the lightest MK bullet in 5.56 is the 69gr. Now, that is not to say that your 55gr won't shoot sub-MOA, it's just not optimized for it. Odds are, if it's quality ammo, it will run well through the upper and shoot sub-MOA. The fact that the upper has a 1/7 twist is also not an issue. I've heard lots of people say it "over-stabilizes" the bullet, but I've yet to see a bullet be "too stable". The issue would be that spinning a bullet faster could cause more "wobble" due to any minute differences in copper jacket thickness. This is why it goes back to the quality of the bullet itself since when using a quality bullet this is just a phenomena we don't see especially at the effective ranges this weapon is used at. There is absolutely no downside to having a 1/7 twist barrel on 5.56 platform. It is simply the most versatile twist rate to have and allows you to shoot all available ammo with the overall best results.

Currently, there is a lot of research and work being done in the long range field of shooting that is using faster twist rates than recommended for the bullets they are using and they are not seeing any degradation in accuracy. We are coming to the conclusion that the greenhill formula is a bit dated to an era where the bullet construction was not what it is today. There are guys shooting amazing groups out to 1500-1600 yards with barrels that have way too fast of a twist rate according to greenhill.

Thanks
Monty

Great info.

Thanks