BROWNELLS - AR-15 GAS BLOCK KIT MODULAR

This gas block kit fits great, the extra rails are very useful, thank you.

we got in the gas block - bayonet lug. went on great - fast, with a AR 15 roll pin starter. add 2 small drops of blue lock tight on all 2 or 4 Alin screws, to be safe!

Have over 4000 rounds thought this gas block at a high rate of fire without one malfunction. Outstanding part, very useful.

ejecting rounds @ 2:00, ck rings good, block is tight & level, any suggestions

The measurements, specifically the ID was spot on .750. It had a good tight fit on my barrel, with a little soap to slick it, it went on no problem. The only thing to point out is the rail on this is lower than most rail systems / hand guards w/ a rail, so you won't be able to do much with it. Make sure you measure twice and ensure this is what you need and not something with a taller tail on top. Also, ensure whatever hand guards you are using allow bottom access to tighten the three Allen screws in this block, even with the tight fit, you need to secure those screws. I would offer that this gas block would be perfect for standard old school AR / M16A2 style hand guards as they "end" before the gas block "begins" and the addition of this rail will rise above those types of guards. If your rail system covers the bottom of the gas block area, chances are you won't be able to access / tighten the set screws and this will become a useless piece of metal. Also, it does not come with a pin for the gas block, it requires a tad bit longer roll pin than the standard AR front sight base takes, while you can use a standard length roll pin just fine, it will be short on both ends if that matters to you.