LoPro Gas Block Selection

[Knicks]

Im working on a buddys build. We purchased a BCM middy upper assy which came w/ a FSB installed. He's adding a free flaot rail so that FSB is being replaced with a lopro gb. Im seeing these things as low as 10 bucks and upto 100 for adjustables. Can I expect decent results from a $25-30 gasblock? Ebay seems to have decent prices well known brands and great prices on brands I've never heard of. Would it be smart to choose from a known company like YHM?

http://yhm.net/low-profile-gas-block-pinch-screw.html

I also need an adjustable for my 308 build. Leaning toward Syrac at 90-100. Are there other MFG's I should consider?

 

[Gillham]

Why a pinch design instead of one that's made to the OD of your barrel @ the gas port?
As for an adjustable for your 308 build - again, what size?

http://www.bravocompanyusa.com/Gas-Block-s/44.htm
https://www.rainierarms.com/?page=shop/browse&category=ar15/m16_replacementparts-upper_gasblocks
https://www.primaryarms.com/AR15_Gas_Blocks_s/65.htm
https://dsgarms.com/rifle-ar15-upperparts-gas-block-tubes
http://www.aimsurplus.com/catalog.aspx?groupid=590&name=Gas+Blocks

Should get you started. Those companies really only sell quality products. If you've never heard of the company - don't buy it.

 

[oilspill]

You already have one - cut down the FSB.

 

[AntiHippie]

I just tried an adjustable for the first time today when I test fired my new Blackout pistol build. Was the Syrac Ordnance Gen II. I never fired it with a non-adjustable for comparison, but I fired it with it wide open, and with minimum gas necessary to cycle.

The overall reduction in recoil and such wasn't as remarkable as I had hoped, but the difference between wide open and just enough open was VERY apparent. I'm sold on adjustables and will use them again if I build another AR, or when I replace the hand guard on my M&P-15.

 

[7.62x39]

I really like these, I have used them on 4 builds now. They are one of the very lowest available and will fit under any FF tube. They are accurately sized, use 3 set screws instead of 2 like most and priced reasonably (under $40 with C&R)

http://www.brownells.com/rifle-part...-15-m16-low-profile-gas-blocks-prod23163.aspx

 

[2nd-amendment]

The YHM blocks are fine with a good barrel (i.e., that has an appropriately sized gas port). I personally like a set screw vs clamp style, but either should work if it will fit under your chosen rail.

The best two adjustables seem to be the Syrac and SLR blocks. Both get good reviews and are designed so the adjustments will not move unless YOU move them. I have used both and would recommend both. They are more money but can be worth it depending on what you're building.

 

[exo]

Why a pinch design instead of one that's made to the OD of your barrel @ the gas port?

That's not why it's built like that. They're calling it "pinch" but it's just a clamp design. Secures to the barrel by clamping rather than by setscrew.

 

[mclina]

I've built two free-float AR's. One I just cut down the standard FSB and kept grinding until it cleared the tube. I smoothed it as best I could and blued it, but it still looked pretty rough. That particular rifle had a solid tube on it, so you can't see the gas block without removing the tube.

On the second one, I used one of these:

http://www.veriforcetactical.com/product/low-profile-gas-block-for-750-barrels-ar15-m4/

I know, $12 bucks seems way to cheap for something like this, but I have hundreds of rounds, through this rifle, and it has not given me any problems.

 

[exo]

I've built two free-float AR's. One I just cut down the standard FSB and kept grinding until it cleared the tube. I smoothed it as best I could and blued it, but it still looked pretty rough. That particular rifle had a solid tube on it, so you can't see the gas block without removing the tube.

On the second one, I used one of these:

http://www.veriforcetactical.com/product/low-profile-gas-block-for-750-barrels-ar15-m4/

I know, $12 bucks seems way to cheap for something like this, but I have hundreds of rounds, through this rifle, and it has not given me any problems.

It's $12 because it's aluminum. I personally would not use an aluminum gas block on an AR15 I might have to trust my life to; just my opinion.

 

[Mattyd7]

Just get the YHM low profile block. You can get either the clamp or the setscrew version depending on what you like better. Should be able to get them under $25 without trouble. Unless you need adjustable, I don't see much gain in paying more. All it is is a block of steel with a hole drilled in it. You're going to cover it with a handguard anyways.

If its a solid handguard and you totally won't see the block, cutting down the FSB is a great idea too. Then you don't have to remove it and have the holes in the barrel from the pins.

 

[dgrafton]

The last two builds I worked on, I used YHM with setscrew and my friend used Spike's with setscrew. I dimpled the barrel for extra security on each. No problems at all with a few thousand rounds through each.

The only difference was the finish of the parkerizing on the Spike's was a bit off from the YHM barrels. Once the handguard was on you couldn't tell.

 

[mac1911]

I used the inexpensive one from RRA. set screw style...my barrel was not dimpled and i have not got around to doing so.....still tight.

 

[hv55maxx]

No complaints with the BCM low pros I've used.

 

[dcmdon]

It's $12 because it's aluminum. I personally would not use an aluminum gas block on an AR15 I might have to trust my life to; just my opinion.

I used an aluminum JP adjustable block on my .308 build. It works great. I was trying to keep the weight out at the end of the muzzle down, and this rifle isn't something I'm going to be doing mag dumps with.

I've also got one on a lightweight .223 AR I built. Its been run hard and hot. Never had a problem.

 

[exo]

I used an aluminum JP adjustable block on my .308 build. It works great. I was trying to keep the weight out at the end of the muzzle down, and this rifle isn't something I'm going to be doing mag dumps with.

I've also got one on a lightweight .223 AR I built. Its been run hard and hot. Never had a problem.

I don't know... IIRC Supermoto had an aluminum gas block that was cut through. Granted, the gas port on that barrel was too large, but still.

 

[dcmdon]

I don't doubt that an aluminum will be cut faster than steel.

I'd be curious to see how beefy it was, whether it was 6064 or 7075, and how many rounds it had through it when it failed.

I do agree with your general point that steel is more bulletproof. But sometimes saving 3 oz way on the end of the bbl is worth it. Some times it isn't.

Don