Free Shipping & Free Returns*

FREE SHIPPING on Over 250,000 Products

Enjoy free shipping during the holidays! Shop now and get Free Value Shipping on most orders over $49 to the contiguous 48 states, DC and to all U.S. Military APO/FPO/DPO addresses.

Enjoy Our Extended FREE RETURNS

We want to ensure that making a return is as easy as possible! With our Hassle-Free, Extended Holiday Returns, eligible orders placed from November 12, 2025 on will benefit from an extended return deadline (January 13, 2026 or 30 days after receipt of your order - whichever is later). We'll even cover the cost of return shipping. Learn more about our Return Policy.

Shopping Cart
SLR Sentry 7 .750 Adjustable Gas Block w/ .450 in. Set Screw Spacing
As Low As $141.64 Save Up to $11.18
View Product
Compare (0)
Most Helpful Positive Review High quality adjustable gas block
This block is a bit pricey but definitely shows the quality in the craftsmanship. Really nice machining and tight tolerances. Using this on a LaRue stealth barrel which are very accurate 1/2 moa barrels but they run notoriously over-gassed so being able to use the slr block to adjust pressure is a b...
Read More...
Most Helpful Negative Review GTG GAS BLOCK
Alright, so the gas block is premium. The fit and finish is second to none. I was unsure what to expect, but it really is a manufacturing work of art. The tolerance was tight, it practically stays on the barrel without set screws. I am really impressed with the product, but SLR is a disappointme...
Read More...
Show
Sort by
Filter by

Keep it simple

by Gunner257, Verified Owner from SD, United States Written on October 2, 2025
All adjustable gas blocks (in my experience) accumulate carbon fouling. These Sentry 7s are simple and easy to service in case of excessive carbon buildup. Disassembly is straightforward, and rebuild kits are available if you call SLR.
Would recommend: Yes
Was it helpful to you? Yes | No

Got my AR10 cycling perfect

by BigCasino, Verified Owner from CA, United States Written on February 10, 2025
I had an aero adjustable block on my AR10 sniper build & t just wasn’t cycling correctly after testing everything finally broke down & replaced it with the sentry. Cycling like a dream now.
Pros:
  • Price
  • Adjustable
Cons:
  • None
Would recommend: Yes
Was it helpful to you? Yes | No

adjustment gas block

by Prith Phay, Verified Owner from MA, United States Written on February 25, 2024
Best thing ever if u like to tune your AR. Easy to tuned great quality.
Would recommend: Yes
Was it helpful to you? Yes | No

The best gas block for Larue barrels.

by Art, Verified Owner from NV, United States Written on January 25, 2024
I have a couple of these that I use with Larue barrels. The .450” spacing is dead on and you can tune the gas very precisely to your application/setup.
Pros:
  • Perfect fit on Larue barrel dimples.
Cons:
  • None
Best Used for:
  • Larue barrels
Would recommend: Yes
Was it helpful to you? Yes | No

No problems so far

by Cody, Verified Owner from TN, United States Written on November 21, 2023
Fit and finish is good. Adjustment has a nice detention feature
Pros:
  • Adjustable
Cons:
  • No cons - in my opinion!
Best Used for:
  • Tuning an adjustable gas system
Would recommend: Yes
Was it helpful to you? Yes | No

Best adjustable gas block

by Eric from MN, Verified Owner from MN, United States Written on May 21, 2022
This gas block by SLR is by far the best adjustable gas block I've used. It has a very nice retention system that is easily servicable. I use it on all my builds and my friends builds. I've never had one move the adjustment on its own. Rock Solid.
Would recommend: Yes
Was it helpful to you? Yes | No

Well built and Adjustable

by Andy, Verified Owner from VA, United States Written on October 22, 2021
Adjustable gas blocks are one of those things you don't "need" but they can definitely help take your shooting game to the next level during a competition. If you have a slightly gassed up rifle. This can help tune it in. If you have a shorter barrel and running suppressed you may also benefit from this. It can help reduce wear and tear on your internals and give you a slightly better shooting experience, but honestly how many of us outside of a trigger puller are going to use our rifles enough to justify this gas block vs wear and tear on internals? Only you can answer that.

Again you don't need this thing to shoot, or even shoot well. After you use it and setup your rifle it can help fine tune it if that is your thing.
Pros:
  • well built
  • Adjustable
Cons:
  • more moving parts than Eugene wanted...
Would recommend: Yes
Was it helpful to you? Yes | No

Best Adjustable Gas Block (AGB) Out There

by Slim, from TX, United States Written on September 25, 2021
I've had multiple AGB over the last 12 years. These SLRs have been the ones that have endured the punishment of hot loads, high pressure, and running suppressed. They are one of the few that you can take apart and service yourself. A couple of times I have put too many rounds down the barrel and an AGB's adjustment screw had frozen up. The SLRs have a head on their adjustment screw that you can clamp a vice grip on and work free. Others I have had to send back to the manufacturer for service. Remember, CLP is your friend and should be applied to the adjustment screw every couple of range sessions while you run the screw in and out.

I have found SLR's customer service to be the best. They sent me rebuild kits without hesitation. I had one gas block that would not fully close and they offered to send me a replacement.

Yes their AGBs cost a bit more but they have been well worth it for me.
Would recommend: Yes
Was it helpful to you? Yes | No

best bang for your buck

by Robert Shields, Verified Owner from CA, United States Written on July 2, 2021
Best bang for your buck, pun intended. I installed a lightweight BCG on a 300 blk out build of mine as well as this GB and this thing worked flawlessly easy to adjust and the spring detention positive click system worked amazing well done
Would recommend: Yes
Was it helpful to you? Yes | No

great gas block

by Mac, Verified Owner from MI, United States Written on February 22, 2021
I have several of these SLR adjustable gas blocks and it is one of the best. The positive response click makes them super easy to adjust. Easy to install and looks great under the hand guard. Front access for adjustment.
Would recommend: Yes
Was it helpful to you? Yes | No
There are no reviews that match your criteria. Would you like to review this product?