Building a 300 upper - opinions/suggestions needed

[voodoo_man]

Isnt the whole point of 300blk so that you dont need an adjustable gas block?

[schambers]

You do not need an adjustable gas block if you have a pistol length gas system.

[voodoo_man]

You should not need an adjustable gas block if you have a pistol length gas system. With a carbine length you might.

Thats what I though.

[schambers]

Forgot to mention this in my last post. I'll be running a colt H2 buffer and Springco white spring.

That combination should be able to run supers and subs, suppressed and unsuppressed with no problems

[SINNER]

There is no doubt an improvement with adjustable gas block if you are switching from subs to supers and taking a can on and off. It will run fine with a standard block but you can definitely reduce the blowback. Being a lefty it is quite clear there is a difference.

[SINNER]

Not what I needed to read 3 days before mine is due to arrive ;P

Having seen some of your quality builds in the past I know this little blaster is going to be a beast. *sub'd*

They are a top quality block don't get me wrong. The seekins is harder to adjust because you need to access it from the front and side. I am still using a Syrac block on a new build because it's under the rail too far. Just be aware backing the screw out and cleaning it every 4-500 rounds will save you some headaches. a touch of nickel based anti-seize certainly helped on the threads.

[DutyUse]

They are a top quality block don't get me wrong. The seekins is harder to adjust because you need to access it from the front and side. I am still using a Syrac block on a new build because it's under the rail too far. Just be aware backing the screw out and cleaning it every 4-500 rounds will save you some headaches. a touch of nickel based anti-seize certainly helped on the threads.

Cool. Thanks for the pro tip :D

[SwissyJim]

Thanks... I'm pretty happy with the build myself. Only my 2nd AR build, but I could not be happier. Runs like a champ and is SUPER fun to shoot. Pretty near 'Hollywood Quiet' with the Specwar762 and my reloads.

As far as the adj gas block, to be honest - once I got it dialed in and set where I want it, I have not changed it since. In the process of testing the initial build, and some reloads, I was changing it quite a lot. But, I have it set in a position that allows my suppressed sub loads to work perfectly (BHO on last round), and the occasional super load runs as well unsuppressed. Honestly, sicne I got the Specwar, I'd say 90% of the shooting I do with this is suppressed sub loads.

Not only that, but there is less gas going thru than I think there would be with a non-adj block and therefore the recoil is less. With the recent addition of the JP captured buffer spring, the recoil is damn near non-existant. By far, my most fun gun to shoot.

If you're thinking home defense,look at the Lehigh Defense 194g projectiles... about the only subsonic bullet that will expand at sub speeds. Not cheap at $1.50 per bullet, but I tested them in gel and they do in fact expand (quite nasty I might add) as low as 900fps. They claim as low as 700fps but I only did as low as 900.

And for cheaper 'plinking' sub loads, SPS sells Nosler 190g Custom Competition 'blems' pretty cheaply - 1/2 the price of 208Amax's. And they give First Responder discounts.

[SwissyJim]

There is no doubt an improvement with adjustable gas block if you are switching from subs to supers and taking a can on and off. It will run fine with a standard block but you can definitely reduce the blowback. Being a lefty it is quite clear there is a difference.

Thats what I found... even with the pistol gas, a standard block was still overgassed. With the adj block I was able to dial it down even more, while keeping the function of both sub and super loads, suppressed and un-suppressed. To me, it was worth the extra $ for that reason -first guy I let shoot it at the range thought it was a .22 due to the almost non-existent recoil. I kinda laughed, as the suppressor was a tad bigger than a .22 version

[tact]

My 300 build is currently in parts as I wait for BDL to get up and running again for some paint.

I went with a Fortis upper microslicked inside, Battle Arms lower, Danger Close 9" 1/7 w/5R rifling, KAC rail, MVB Arc stock, St. Croix titanium BCG, 2A titanium GB, melonite gas tube, CMC flat 4# duty trigger........and a Saker762. I will most likely switch out the rail for a longer one as I've ordered another Saker so I am not worried about taking it on and off.

I don't buy the need for an adjustable GB either.

There's a dust cover on Article 15 Clothing you might like, VDM.

I am curious why you don't just buy the PWS Mk109 instead?

[DutyUse]

My 300 build is currently in parts as I wait for BDL to get up and running again for some paint.

I went with a Fortis upper microslicked inside, Battle Arms lower, Danger Close 9" 1/7 w/5R rifling, KAC rail, MVB Arc stock, St. Croix titanium BCG, 2A titanium GB, melonite gas tube, CMC flat 4# duty trigger........and a Saker762. I will most likely switch out the rail for a longer one as I've ordered another Saker so I am not worried about taking it on and off.

I don't buy the need for an adjustable GB either.

There's a dust cover on Article 15 Clothing you might like, VDM.

I am curious why you don't just buy the PWS Mk109 instead?

Wow that sounds like one HELL of a build. Have you started acquiring parts yet?

[voodoo_man]

I would buy a complete gun but ive got these parts comin in for less than retail so I couldnt say no.

[tact]

Wow that sounds like one HELL of a build. Have you started acquiring parts yet?

Yes....all here except the BCG and rail which should arrive any day.

[tact]

I would buy a complete gun but ive got these parts comin in for less than retail so I couldnt say no.

I was basically in the same situation and really wanted the mk109 but will end up with this build for now.

[voodoo_man]

...so I ran into a little snag while doing research on parts for this build.

I got a Fortis Switch rail which I posted pictures of several times, but its a little too long...



As you can see I need like 4-5 inches of muzzle device (which is eventually going to be a suppressor but that'll be a while until the stamp comes back), so I need something to put there in the mean time.

Suggestions?