All,

I'm putting together the pieces on a precision build around a .223 Wylde White Oak 20" DMR barrel. Will be using this primarily to predator/varmint hunt and improve my marksmanship (in addition to teaching myself how to shoot with milrads via a FFP mil/mil optic I'll pick up - likely the SWFA SS 3-15x). I may get into practical/tactical precision shooting with this setup if there are groups in my area.

From what I've read, for precision shooting a clamp-on gas block is basically mandantory, but there's also concerns of those clamps working loose. It's not as rough-and-tumble as a taper pinned gas block.

A. Go Adjustable?

Since I'm getting a clamp-on gas block regardless, is there a good or justifiable use case for an adjustable gas block here in addition? I don't have any plans on purchasing a suppressor for my rifles, and since it's a rifle-length gas system (and a 5.56 anyway), it's hardly going to be beating my shoulder up.

B. If Yes, What Model: JP or Syrac?

If an adjustable gas block has benefits outside of shooting with suppressors, what model makes the most sense?

On one hand, the JP adjustable model has four screws, which seems like it would provide a more secure clamp onto the barrel. But, there's no way to secure the adjusting screw. Since it's a clamp on anyway, there are potential issues all around for things working loose.



On the other hand, the Syrac has the detent system built in, but that also means you've got to use both hands to adjust the gas, which I'm fairly ambivalent about. I don't know how much of a factor that would be in the real world.

The detent and screw up front don't make much difference to me, as the gas block will be exposed with the 12" handguard I've got. Actually, I think I'd like the position on the side like the JP a little better anyway; easier to get to.



If an adjustable gas block isn't worth it, then I'll probably just go ahead and snag a VLTOR clamp on model and be done with it.

20" RLGS set-ups are very smooth-running, and rarely need an adjustable block unless the port is cut too large.

The issue with set screw chokes right above the gas port is that you create more of a blast furnace effect in the gas port, which leads to early port erosion, and accuracy will suffer earlier.

There is no need for an adjustable gas block for the set up you described.

I don't know if you "need" an adjustable GB. Just for yuks I put one, a Syrac, on my DPMS bull 20 and love it. It got rid of the "twang" from the buffer spring by not slamming it back, now I don't loose sight of the target through the scope. And the brass ends up in a nice three foot diameter spot about 12ft away.

I have the syrac on an 18" WOA.  

If you plan to shoot suppressed it's definitely a good idea.  

Just finished a varmint rig build. White Oak 20" 1x12 twist with heavy barrel upper for my North Dakota prairie dog trip next month.

I debated adding an adjustable gas block since I'll be running a SilencerCo Saker 556 can 99.9% of the time.

I added a Syrac adjustable gas block.

Love it!!!

Clamp on is bad.

I have a set up similar to what your describing, and I use a gen 2 syrac. I like the detent system, and it's easy to access. Just shoot some cleaner in it every now and then, and back the threads out and put some grease on them or keep it working smooth. As mentioned, this will one day run suppressed and that was the original intent. However, I will say this about using it non suppressed; you can dial in a softer shooting rifle for the ammo you use. This is a huge advantage for faster follow-up shots. That could be pretty handy in your competitions.