Adjustable gas blocks

[montana]

Having used and evaluated many adj gas blocks through out the years I have a pretty good perspective on their strengths and weaknesses. I take a different approach from many by preferring to monitor the gas to control BCG velocity, while using the lightest buffer possible to mitigate recoil impulse. The common opinion is to use an H or H2 buffer, but the down side is the heavier the recoiling mass, the heavier the recoil impulse.. I have my favorite adj gas blocks as others, but my opinion has always been based on the quality, performance, ease of maintenance, ease of repair, ease of adjustment and effectiveness..My favorite for a long time has been the SLR, but they are not perfect and have the same weakness as the others I have tried. The common weakness has always been the springs, accessing the adjuster with a tool and the ability to repair and replace parts. Every gas block I have used that has a spring will eventually fail, including the SLR leaf spring..The SLR leaf spring has held up great compared to the coil spring designs I have used, but they will fail with a high round count. SLR has always replaced their parts and even the entire block for free when this happens, but I always wished there was a better option.. I have recently discovered a new design I'm going to be testing called the Rifle Speed that looks like a game changer..It is quite expensive and needs a proprietary straight gas tube, but takes a different and a better approach to adj gas blocks in my opinion. The simplicity of the design and maintenance may well be the adj gas block I have been looking for..With the Rifle speed adj gas block, there is no need to carry an allen wrench or other tool for adjustment. With this design it is easy to access for quick adjustments for ammunition changes, cold weather or when using a suppressor.. Of course when using any gas block the importance of the QC and fit with the barrel journal is a major concern, so I will be testing this new adj gas block this year and will give a summary of my findings...

https://www.riflespeed.com/RIFLESPEED-Ga..._p_12.html

https://www.youtube.com/watch?v=NR7Mr8MB9Tc

[mtnlvr]

Damn! Pricey is right. Gas tube sold separately I presume. If it works as good as it looks I suppose price is a little less critical. Looking forward to your report.

[Happy2Shoot]

Every gas block I have used that has a spring will eventually fail, including the SLR leaf spring.

https://www.riflespeed.com/RIFLESPEED-Ga..._p_12.html

https://www.youtube.com/watch?v=NR7Mr8MB9Tc

After watching the video I feel this may sill be a concern for you. That wavy washer is a spring is it not? The part that goes on at the 30 second mark.

[montana]

After watching the video I feel this may sill be a concern for you. That wavy washer is a spring is it not? The part that goes on at the 30 second mark.

This spring is not buried inside the gas block like other springs but is on the outside with limited contact areas. Here is the information from their sight regarding replacement of the plunger and spring...

Inspect the Plunger for erosion when conducting the 1500-round cleaning process detailed above
or each time the plunger is removed during disassembly. Some erosion is normal. The Plunger may
be rotated in varying orientations during reassembly to limit erosion in any one portion of the
Plunger. Replace Plunger if more than 50% of the plunger’s diameter has been eroded, if function
changes, during barrel replacement, or during up-echelon maintenance. Plunger-replacement
interval, like barrel-replacement interval, will vary according to firearm configuration, chambering,
firing schedule and can be between 10,000 and 25,000 rounds. Replacement of the Wave Spring is
recommended any time a Plunger is replaced. Wave Spring and Plunger replacement are user-level
tasks.

That said, this is why I want to test this adj gas block myself..Every latest and greatest doodad means nothing until proven..If I can get 5000 rounds without any broken springs let alone their claim of 10,000 to 25000 rounds will be a win for me...

The other positive point of this system I forgot to mention is the ability to exchange different size plungers to fit the caliber and gas system..https://www.riflespeed.com/RS-Replacemen..._p_14.html

[Klem]

If I can get 5000 rounds without any broken springs let alone their claim of 10,000 to 25000 rounds will be a win for me...
.https://www.riflespeed.com/RS-Replacemen..._p_14.html

Montana,

That round count would be the life of most AR's which is more than reasonable. If a recoil spring can last that long there's no reason why a gas block spring can't do the same.

It looks like a good idea.

Klem

[myrifle]

This spring is not buried inside the gas block like other springs but is on the outside with limited contact areas. Here is the information from their sight regarding replacement of the plunger and spring...

Inspect the Plunger for erosion when conducting the 1500-round cleaning process detailed above
or each time the plunger is removed during disassembly. Some erosion is normal. The Plunger may
be rotated in varying orientations during reassembly to limit erosion in any one portion of the
Plunger. Replace Plunger if more than 50% of the plunger’s diameter has been eroded, if function
changes, during barrel replacement, or during up-echelon maintenance. Plunger-replacement
interval, like barrel-replacement interval, will vary according to firearm configuration, chambering,
firing schedule and can be between 10,000 and 25,000 rounds. Replacement of the Wave Spring is
recommended any time a Plunger is replaced. Wave Spring and Plunger replacement are user-level
tasks.

That said, this is why I want to test this adj gas block myself..Every latest and greatest doodad means nothing until proven..If I can get 5000 rounds without any broken springs let alone their claim of 10,000 to 25000 rounds will be a win for me...

The other positive point of this system I forgot to mention is the ability to exchange different size plungers to fit the caliber and gas system..https://www.riflespeed.com/RS-Replacemen..._p_14.html

I will be ordering 24 of them very soon.

[LRRPF52]

OK, that’s actually really cool.

The problem with tiny coil springs in gas blocks is the thermal cycles they are subjected to.

Tiny springs don’t handle radical thermal gradients well at all, which contributes to them failing quickly.

As everyone knows, gas blocks get really hot, really fast.

This exposed leaf spring should mitigate a lot of that since it is in ambient atmosphere and has a lot more mass to it.

[Bonas]

That does look like it has potential. It's kind of surprising no one has really nailed an adjustable gas block for ARs. I recently put a Strike Industries collar adjustable block on a build. I like it it. It's too new to say how it will hold up. It's easily adjusted through the handgaurd with any sort of punch, allen wrench, etc. It's not perfect, but I like it better than screw adjustable blocks.

[LRRPF52]

I’ve always liked the FAL’s adjustable gas, which is an adjustable bleed system, rather than a more enclosed choke.

[Harpoon1]

I’ve always liked the FAL’s adjustable gas, which is an adjustable bleed system, rather than a more enclosed choke.

Exactly. It’s always baffled me too! No pun intended.

[montana]

I’ve always liked the FAL’s adjustable gas, which is an adjustable bleed system, rather than a more enclosed choke.

I had a full auto dealer sample FN FAL in the early 80's that started short stroking and finally quit as the adj gas system loosened up and needed replacement.. There are pro's and cons to any adj gas system and all adj gas systems need maintenance..

[PNWTargets]

Interesting post. I use Superlative Arms adjustable gas blocks all suppressed. The 6.5 Grendel’s I have work good with a red Sprinco Spring and H2 buffer.

[IlliniFan]

I shoot my 12.5", 16", and 20" 6.5 Grendel ARs suppressed with Dead Air Sandman-S. All run great with an H2 buffer (12.5" and 16" with Geissele Super 42 Spring, 20" with JP SCS H2). Fixed gas block on the 12.5", SLR Sentry adjustable gas blocks on the other two.

When initially test firing the 12.5" pistol without a suppressor the H2 buffer was a bit too much for it to cycle reliably. H1 buffer worked great without a suppressor.

[TruLbrt]

Happy with SLR 100%. I can have quick access to the adjustable gas metering screw by choosing a rail length that leaves the screw at the open end of the rail. I would build a lightweight rig with intention to save weight everywhere, lw bcg included, and not offset with a fat rail or gasblock, etc. The collared adj gas block will just make the build muzzle heavy too.

[Growler]

Hey Montana,

Curious what your experience with this product has been. How many rounds do you have through this system? Any surprises?

This seems like a very smart design in the tool-free adjustment space. If one expects to be using a wide range of bullet weights or both suppressed and unsuppressed, this would be very helpful.

Interested in the gas control. Given the wavy spring loaded pin is a unique design, did it give predictable control over gas as you made adjustments to dial it in?

Any assembly issues?

Thanks

[montana]

Hey Montana,

Curious what your experience with this product has been. How many rounds do you have through this system? Any surprises?

This seems like a very smart design in the tool-free adjustment space. If one expects to be using a wide range of bullet weights or both suppressed and unsuppressed, this would be very helpful.

Interested in the gas control. Given the wavy spring loaded pin is a unique design, did it give predictable control over gas as you made adjustments to dial it in?

Any assembly issues?

Thanks

I haven't put enough rounds through it to even see any significant erosion on the plunger. Been busy with my business and a shoulder surgery. I can say I'm happy with the fit and quality of the barrel journal bore. The design is by far the easiest adj gas block to disassemble and maintain I have ever used. The parts are simple to access and replace if needed.I want to test the plunger range with and without my suppressor using different types of ammunition.There are different plunger lengths to fit different calibers and needs if required. I don't see any negatives to this adj gas system other than needing a proprietary straight gas tube, but until I get some actual time and rounds through it, I'm going to hold off on any real judgments. That said, it looks very promising..

[keystone183]

I too love SLR. Their customer service is simply unbeatable. No company across any other industry has better service than they do! HOWEVER....the problem with their blocks is if you don't maintain them regularly, especially if shooting suppressed....the will carbon up and then are a pain to clean/replace parts. I have been moving to using Rubber City's adjustable gas key. It has its drawbacks, but it also has advantages i like. Now, i only have one of these, but....so far it has been great, and i don't know how long the detent spring will last....but i would guess its pretty robust? This design to me has legs!

https://www.strikeindustries.com/si-ar-cagb.html

[montana]

I too love SLR. Their customer service is simply unbeatable. No company across any other industry has better service than they do! HOWEVER....the problem with their blocks is if you don't maintain them regularly, especially if shooting suppressed....the will carbon up and then are a pain to clean/replace parts. I have been moving to using Rubber City's adjustable gas key. It has its drawbacks, but it also has advantages i like. Now, i only have one of these, but....so far it has been great, and i don't know how long the detent spring will last....but i would guess its pretty robust? This design to me has legs!

https://www.strikeindustries.com/si-ar-cagb.html

A lot of excellent looking designs on the market these days. Making adj gas blocks more bullet proof, user friendly and having more choices is always a positive..When adding any non mil spec part to an AR rifle system, it can have a ripple effect with the rest of the rifle system, especially if the builder doesn't understand the dynamics of the AR platform..Any adj gas block- bolt carrier group will leak more gas than mill spec and a rifle already running on the edge can have negative consequences. Adding the tolerances of the parts to the system also adds another part to the equation that can have positive or negative effects.. Basic understanding of this process can prevent a lot of headaches if a problem arises..

[montana]

Just an up-date on the Rifle Speed Adj gas block.https://www.riflespeed.com/RIFLESPEED-Ga..._p_12.html

I can say without hesitation this is the best adj gas block I have ever used. It is a game changer..I'm in the process of replacing my other adj gas blocks where warranted.

The only criticism I have is the tension spring is a little weak for my taste, but was easily rectified by adding a second spring. It is so easy to adjust the gas in the field without searching for allen wrenches and fumbling with the weak adjuster screws. I have not oiled or serviced one adjuster for over a thousands rounds on one of my 5.56 rifles and it has been working perfectly..

With certain length gas tubes and hand guards it would be necessary to modify the hand guard to have access to the adjuster..Not a problem if done correctly..
I also had to modify the Picatinny Accessory Rail's screws on two of my carbon fiber Faxon hand guards for clearance reasons which was an easy fix.

If you want a bomb proof adjustable gas block, then the Rifle Speed is the one you should get..Ill say it again, the Rifle Speed adj gas block is a game changer..