I got a good price on the Geissele Super Gas Block that I couldn’t pass up. However, after doing some reading, I’m having a bit of buyers remorse. I’m wondering about how well the pin will stay in if I use the rifle heavily. From what I was reading, if you’re going to pin a gas block, it really needs to be a taper pin and not a roll pin. With that in mind, is the SGB good for heavy use, or is it more of a precision/bench type of gas block?
Well, using the proper size drill bit IN A DRILL PRESS is the key to proper pinning of a gas block. Using a handheld drill is a great way to swage out the pin hole. Roll pins are actually a great way to fasten gas blocks to barrels IF the pin hole is in spec. Even better is a spiral roll pin, like Clint at Black River Tactical uses for his MicroPin gas blocks. I’ve used those and they have no peer for price and quality.
If not, loctite green 620 sleeve retainer will hold that pin perfectly well. In fact, if you properly apply the 620, you’ll have a bitch if a time driving the pin back out should you choose to attempt that. I’ll bet you deform the pin before it begins to move. [emoji12]
But, seriously, the Geissele block is great as long as it fits under your rail.
I’m planning on having a gunsmith do the pinning for me; I don’t have a drill press or the money to screw it up.
Also, I’m putting it under an ALG EMR handguard, so i’m hoping it fits, especially since it’s the same company!
You’ll be fine then. If you’re really concerned, have them apply some green loctite 620 to the pin hole and the pin prior to installing it and you’ll be fine. Give it 24 hours to set for the sleeve retainer and you’re GTG.
The Geissele gas block uses a spiral coil pin (similar to that described above for Clint / BRT gas blocks). Properly installed it isn’t going anywhere, even without using any adhesive. I would not use any adhesive or threadlocker on it - no point and you (or your gunsmith) will not like having to remove it if ever needed.
Many rifles survive hard use with only set screws holding the gas block in place. Two set screws and the pin, properly installed, will keep it secure for anything you will do.
I have Geissele Carbon Super Gas Blocks on all my builds (four - I know it isn’t 4,000 LOL) and I haven’t pinned any of them - follow the instructions, get the drill bit they specify from McMaster and install it yourself. The only tip that I could pass on is to put the gas block on and twist it upside down so that the gas port is centered in the first set screw hole (which is the hole they use to drill the gas passage in the block) scribe locating lines and then flip it over and drill away. You don’t have to drill a bunch and I’ve never screwed up the threads.
I have one mounted under a EMR V0 Rail, fits fine!
JM .02.
When done correctly, it isn’t going anywhere. Be concerned about other stuff.
If you make a bold claim that you have tested “other top brands” and they all failed miserably, please be prepared to provide some additional information. Otherwise it’s just internet rumorville.
It would still be “internet rumorville” if I named names. That’s why I specifically didn’t. That’s also why I told the op to test for themselves. Sheesh!
Then please stay out of this thread. Thanks.
BoringGuy45,
I know of a handful of trainer types that have used the Geissele block with no issues. I have a Geissele block on my modified Colt M4 carbine. If the installation is done properly (and I would also dimple the barrel in one spot) and you use Loctite in the screws it isn’t going anywhere.
I didn’t have a problem with any of them walking. I had a problem with smaller parts not being able to handle stress. The straight up broke. The original poster, not you iraqgunz, want to know a more complete answer. Not ONLY if they would walk. As a moderator, don’t live up to the reputation of the ninney whiners so associated with this sight. I don’t see the op asking me to leave. Is this how it’s done here? Some mod swoops in, acts like an ass and tells people who are trying to help to leave?
I echo gunz thoughts. I have a Geissele with about 4k on it on an 11.5 SBR. BCM barrel with the single dimple. Red locktite on set screws and have never had an issue. Roll pin went in the trash the day I got it.
The only issue I had was clearance on a KMR rail. I did need to take a very small amount of material off the thick bottom portion for clearence. It has not effected performance and works 100%.
Just out of Total curiosity… I wonder how far the Set Screw spacing is between the two holes in the Gas Block? I have a Barrel that’s Dual Dimpled for an SLR Adj. Set Screw GB, and I’m wondering if those existing dimples would mate up perfectly w/ the Geissele?
This may be a little off topic from the geissele gas block, but since we are on the subject of pinned blocks…if a block is pinned, should it also be set screwed? I’ve got a BCM block that I had to shave down to fit under a centurion cmr. The heads of the set screws were making contact with the inside of the rail under pressure after I shaved it down so I just took them out.
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Pinning is the strongest method out there… there’s almost virtually No chance it will come unpinned unless you take a Hammer and Punch to it, and even then, some of them are super difficult to remove, without heat and some patience.
I picked up a barrel that shoots pretty well, but has no dimples for the gas block. It’s nitrided. I’ve only put a few hundred rounds through it so far, with no set screw issues, but I don’t really like not having dimples… any suggestions for type of drill bit to use for dimpling a nitrided barrel? Or is there some other reasonable option? I have a drill press but don’t have a mill.
I have and like the BRD dimpling jig. I use a cobalt tipped drill bit.
If you block is cross pinned to the barrel, then no you do not need to use the screws.
The hole spacing is a little different on the Geissele compared to the BCM for instance. The Geissele screw spacing is .056 narrower. If the closet to the shooter set screw is in the identical place on the BCM vs Geissele. The Geissele gas block would be .020 ish closer to the collar. Or less gap between the gas block and the barrel shoulder. Reason I know this is that I made a dimple jig out of a Geissele block that was laying around. After drilling the dimple holes out on the barrel, the BCM gas block screw sets would not line up perfectly. I still use the jig, but only drill one pocket in the barrel and not two.
The overall width of the Geissele is 1.000 and the BCM is 1.003 that I just measured.
Hope that helps…