Centurions CMR's are too small in ID to work.  

There are more rails that work than don't work.  See various customer pics here:http://micromoa.com/pics/



Here is a barrel review from a member here: http://www.ar15.com/forums/t_3_4/660735_Building_SBR_and_need_advise.html

Lot of barrels out there, hopefully some more people can chime in.

Thanks for your consideration!



 

100 rounds?  You shouldn't be having that problem.  I've run over a thousand without moving the plate and while it will be stiff if I don't move it after that many rounds I don't ever need a hammer and punch.

Are you running reloads?   What kind of powder?  Feel free to send one of the setups back to me if you want me to check it out.

I advise customers to move the plate when they are cleaning their rifle.  I use Breakthrough or Firelcean on the regulator plate and that seems to work for me.

Thanks!







 

What's the new hotness in adjustable gas blocks for a 10.5" .300BLK barrel?  The intention is to primarily shoot subsonic rounds with a supressor but I want the ability to run supersonic rounds as well (with or without a can) without it being overgassed and beating my parts to death.

Have you seen our 300BLK testing here?: http://micromoa.com/300-blk-port-size-testing/

A lot of people use our blocks for 300BLK, 6.5, 6.8, 308 etc....in addition to 223/556 of course.

For a 10.5", we could do a .073/OFF/.093 for:

supersonic with and without a can/OFF/subsonic

That would work for FACTORY 300BLK ammo we have tested, standard power spring and up to an H2 buffer.  If you reload, YMMV.

You will be able to know what position the regulator is in by visually looking at it or in complete darkness by feel.  Also be able to adjust with just the tip of a bullet.

If none of those capabilities interest you, you can go with a set screw detent adjustable block.

Let me know if you need assistance,

Thanks!





 

Thank you.  Your Gov'nah is one I have been eyeballing for a while. I especially like the "OFF" position option for super-sneaky-extra-quietness, albeit manually operated.  I have a 10.5" .300BLK barrel with a pistol-length gas system so I will look at your testing link later when I have more time.



 

I do not see a listing for a Govnah with those port sizes on your site. How would I order one with those port sizes?



 

We currently only have 'ready to go' port sizes pre-drilled for the 5.56 versions since we can fall back on a milspec round like LC M193 or M855 to vailidate the testing.  There is NO 'milspec' round in 300BLK...yet.

As seen in the link above, we noticed that the older factory Remington was hotter than the newer stuff and we stopped testing as that variable was changing which is beyond our control.

In addition, many people that run 300BLK reload which introduces more variables.  However, many of those don't mind drilling the plates out on their own to tune to their own exact configuration.

All that said, that testing was just to give everyone ballpark ideas on what worked for us with the configuration outlined on that page.  I know it has worked for everyone that has used that data.



So to do a .073/OFF/.093 for a 10.5" 300BLK you have 2 choices

1.  Order the 3 position custom with the Variant 3 regulator plate: http://micromoa.com/3-position-custom-with-variant-3-regulator-plate/

and drill it out yourself and you can fine tune it to your exact configuration.  Obviously, requires work on your part and testing.

2.  Order the same thing as above and select the option for us to drill it out for you for an additional $10.  There is a box to enter the port sizes desired.  As mentioned, I'm pretty sure it will work for you as long as you're not using some xtra power recoil spring and super heavy buffer.  We used the milspec standard M4 lower configuration....standard power spring and H2 buffer.  As long as you don't go heavier it will work.  This is the fast, no hassle, no tuning option but most likely won't be perfectly tuned for you unless your variables were identical to ours including the same ammo used (which again changed on us).





The variant 3 regulator plates are dimpled in all 3 positions.  We had a Variant1 where we left the middle undrilled and the left and right pre-drilled but of course you get the few oddball customers that want OFF on the left or right so we just decided to do it like this to please everyone.  The plates are pretty hard and you really need a drill press press to get the initial hole drilled after that you can easily enlarge with a hand drill.





Thanks for your consideration!



 

The Krinkov muzzle device that I've seen called a gas booster, is called a flash hider by K-var.  I'd call that a gas booster but whatever.


https://www.k-var.com/shop/KR-007US.html








That really does add backpressure.  I've been using them for a as long as I can remember playing with some full auto 22LR guns.





Brownells adverstises the both of these as muzzle brakes:


http://www.brownells.com/rifle-parts/muzzle-devices/muzzle-brakes/ak-muzzle-brake-prod5735.aspx








They both have little expansion chambers and I'd suspect that they boost the gas some also....likewise, you would think that any muzzle break that does have expansion chambers would do the same but it may be so slight that it would not be noticeable.





The Bulgarian 4 piece 'muzzle brake' also creates back pressure for sure.  I've got some shorty 7.62x39 builds that I've validated with them.


I've been told that the ATF was going to classify them as suppressors as they are supposed to reduce the sound by some very small amount but they had already let a lot of them into the US and didn't.