need help with a gas block

[Lars]

I need your opinion. I have a Dpms in 6.5 Creedmoor and I'm putting a suppressor on it. I want to put an adjustable gas block on and want some insight into what you guys recommend. Thanks for the input.

[Marine24]

I used JP Enterprises low profile adjustable gas block on my heavy barrel .308 AR. Bore diameter was .936

[Lars]

Thanks for the input. The JP is what I've been looking at. I need the .936 dia. as well. Has it helped your rifle function any better?

[MarkCO]

Since Syrac does not make one in the larger diameter yet, the JP is your only good choice.

Here is the rub...JP blocks are INTENDED to be adjusted and then flooded with locktite. If you are shooting a few rounds here and there, not a big deal. Otherwise, you will have some issues. You could always machine an intersecting hole and thread it with a brass set screw if you want to be able to adjust it. The other option is machine a shoulder into the block at the adjustment screw and use calibrated washers and a lock washer.

[Marine24]

I don't run mine suppressed, so setup was pretty straightforward for me. I like the ability to tune the rifle to ensure reliable operation but reduce the amount of recoil. My loads are pretty consistent, so I don't have to deal with the variations that different bullet weights/velocities can introduce but still pretty easy to adjust in the field if you are feeding your rifle different ammo.

[Lars]

I will be going back and forth between suppressed and not, will I have issues getting it to run consistent either way?

[MarkCO]

I will be going back and forth between suppressed and not, will I have issues getting it to run consistent either way?

Suppressed needs less gas, so you will need to set up it for non-suppressed to ensure reliability in both configurations.

[Lars]

Here is the rub...JP blocks are INTENDED to be adjusted and then flooded with locktite. If you are shooting a few rounds here and there, not a big deal. Otherwise, you will have some issues. You could always machine an intersecting hole and thread it with a brass set screw if you want to be able to adjust it. The other option is machine a shoulder into the block at the adjustment screw and use calibrated washers and a lock washer.[/QUOTE] If I set it up with the washers is it then just a matter of removing or adding washers to set it for either configuration? Thanks for the help Markco

[DangerLee_Industries]

I've never had any problems with a Noveske switchblock. If you can track down a 6.8 it might work but you will most likely need to cut your hand guards as well..

[MarkCO]

If I set it up with the washers is it then just a matter of removing or adding washers to set it for either configuration? Thanks for the help Markco

Yep.

[Lars]

So I finally shot my rifle after putting on the adj. Gas block. I set the set screw so my action will just stay open after the last round and everything seems to be working great. Here's my question. Before the adj. Block my velocity was 2648, and after installing I am now averaging 2830 fps. Is this due to more gas going down the barrel or is something off with my chrono. The load is the exact same, and the powder I'm shooting is supposed to be temp insensitive. Any ideas?

[MarkCO]

Something is off with your load or Chrono.

You want to set it where you have it...PLUS 1/2 turn out...or when it cools down...you might have a single shot.

[Lars]

The load came from the same lot that I reloaded when I shot it with the original gas block. The chrono was throwing some fits today. I finally took off the sun shades and it started working so maybe that had something to do with it. I'll just have to try again I guess and see what I get.

[Lars]

So I finally got my suppressor and everything seems to work. I adjusted the gas block down for use with the can and everything works great. I have the set screw completely buried and I'm still getting blowback in my face. It's turned down enough that the gun will not cycle without the suppressor but after what I spent and almost a year waiting, why would I shoot it without. I'm getting gas blowing out where my gas tube pins to the block as well. Any suggestions for that.

[MarkCO]

Most gas blocks leak there, loose fit between the tube and block.