An AR-15 gas block is a relatively simple part. And a gas block either works or it doesn’t. But it’s a pretty big bummer if your gas block doesn’t work when you put your rifle together.
That’s why I have a few go-to gas blocks that I trust. And I figured I’d write up a quick SLR Rifleworks Micro Gas Block review, because I’ve found it to be a trustworthy gas block.
SLR Rifleworks Micro Gas Block Review
I’m familiar with the usual suspects — BCM, Aero Precision, Seekins Precision, and some others — and those gas blocks are solid choices.
But it never hurts to have a few more options, especially if you have preferences in regard to finishes and aesthetics. Also, when it’s on sale, the SLR Rifleworks Micro Gas block comes in at a middle-of-the-road price.
So it’s a good option to have in your back pocket for budget versatility.
Fit and finish
The fit and finish of a gas block generally boil down to three things: barrel fit, smooth edges, and external finish.
The barrel fit has to be snug for a good gas seal. The edges have to be properly deburred to avoid marring the barrel finish. And the external should be consistent.
It’s nearly impossible to check the finish inside the gas tube channel. But, if the finish on the outside is clean, the finish on the inside should also be good.
The barrel fit is indeed snug. And there are no sharp edges anywhere. The SLR gas block slid over the gas block journal perfectly. Two thumbs up there.
Then, the nitride finish is excellent. Also, it looks like they honed the internal bore before applying the exterior finish and polishing the nitride finish.
If you look at the inside bore on many gas blocks, you’ll see that there’s a bit of silver metal showing. That’s because many manufacturers will hone the bore after applying the finish. This removes at least some of the finish.
Note the silver inside the BCM gas block, as compared to the black nitride inside the SLR gas block.
To be fair to these other manufacturers, it’s kind of necessary to hone the bore after applying the finish on phosphate coated gas blocks, because the phosphate finish is a bit rough.
However, SLR seems to have nitrided their micro gas block after honing the bore, which leaves a more corrosion resistant surface on all the surfaces. It’s excellent manufacturing craftsmanship.
Overall, two thumbs up on the fit and finish.
Construction
When I check the construction is usually when I install the gas tube. If the metal is poorly heat treated, a stainless steel roll pin will sometimes chip or deform the roll pin hole.
It’s not a perfect check. The metal has to be exceptionally poor to give way to a roll pin. But the gas block definitely needs to be tossed if it fails that check.
The SLR Rifleworks gas block had no issues with the gas tube installation. And there was no wobble in the gas tube that would indicate an oversized gas tube channel. Everything checks out.
Aesthetics
Up to this point, the SLR Rifleworks Micro Gas block is a relatively standard non-adjustable gas block. But I think the aesthetics give this gas block a leg up over other gas blocks.
I know gas block aesthetics aren’t really a big deal, because the gas block is under the handguard. But I’m a stickler for attention to detail. And you might be able to see your gas block if you have an especially lightweight handguard.
So the aesthetics of a gas block aren’t entirely irrelevant.
And the SLR gas block has a nice all-around aesthetic. The three indents on each side of the block are enough to add visual appeal. But they’re subtle enough not to look out of place on an otherwise standard AR-15.
Also, I appreciate that SLR didn’t laser etch their brand logo on the side or anything. Some brands do that. And I think it’s a bit over the top.
Maybe you don’t care (and many people don’t). But I think the SLR gas block looks great, without being too aggressively styled for a standard build.
Why it’s a great all-around gas block
This is my argument for using the SLR Rifleworks Micro Gas Block for everything:
It looks better than a standard gas block. The quality is higher than most budget gas blocks. And, depending on where you shop, the price is usually lower than a BCM or other high-end gas block.
I’m a fan of mid-high tier hardware. At some point, you get diminishing returns from paying more for the metal. And this gas block seems to fall into that sweet spot where you’re getting the most for your money.
It’s not an absolute budget gas block. But you’re not paying for a brand either. That’s why I think you could easily use this gas block on all your builds and be stoked about it.