AR15 BCG Roller Cams?

Just wondering... has anybody here tried roller cams on their AR BCG's, and if so what'd you think of 'em?

On the one hand I'm considering adding a Hydra-Fire drop-in to my DSA phosphated BCG... OTOH the phosphate was only meant to be a "basic starter" and eventually replaced with a nitrided, NiB or NP3 anyway... other than the price, the POF "Ultimate" with factory NP3, roller cam and one-piece carrier/gas-key design has a certain appeal too. POF has a bit of name reco, HF is "huh, who?"

Reference links:
Hydra-Fire drop-in Roller Cam Pin
POF upgrade kit <broken link removed>
POF "Ultimate BCG" <broken link removed>

I kind of like the idea of reduced drag and wear, but I'm not sure this $100 no-warranty-that-I-know-of BCG+CH combo is really worth the extra $35 to try to fully kit-out with every "would be nice" goodie-bag under the sun--as it is, when I upgrade unless the hand-me-downs go into a parts-box for my gal the CH latch I upgraded is getting downgraded back to as-shipped.

Any experience with these out there in TV Land? :)
Wow! Times they are a changing. So much new cool AR15 stuff. Thank you. Might be required for some low pressure sub sonic short barrel builds. That and spiral gas tubes. For an ordinary AR15? Dunno. If your weapon is subject to over function, (over gassing) then perhaps not. But ... for correcting an under gassed build? Wow!

HB of CJ hundreds of builds. uncounted rebuilds.


This is just my 2 cents and its worth at least that.

Roller cams were designed to reduce cam ware from piston systems in the upper receiver. They really do not enhance anything for a DI system. "Low Drag" is a word made to sell them to DI users.

I would never use one in a DI system as it serves no practical purpose. I run them in the piston uppers I have to prevent receiver ware.

If its not broke don't fix it.
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In a DI gun the gas uses the locked bolt as part of the piston. The pressure pushes the carrier back against the locked bolt which unlocks the bolt itself and the the momentum pushes everything rear ward, fairly fluid motion.

The piston gun uses a rod to wack the carrier rearward. Which unlocks the bolt rather forcefully. Which yanks the cam into the receiver causing wear. This part of the receiver will wear down and not effect operation much. A rolling cam pin helps make this motion more fluid like the DI gun.

Picture of piston gun cam to receiver wear.

The concern I have is with less drag it would require less gas pressure to operate and the Roller Cam Pin even claims it needs less gas pressure to operate.

This adds a whole new “can of worms” as I have seen most barrels are over gassed as it is (gas hole drilled to big) so the use of H2 or H3 buffers are required to slow cycle time and keep from beating the gun to death if you shoot a lot. Yes they will run on a lighter buffer but recoil is harsher and wears parts out quicker. In my opinion.

So less drag would mean you buy a Barrel and drill your own gas hole or you may need to run an even a heaver buffer for a smooth operation.

Lighter less drag may not be to your advantage on a stock over the counter parts gun but if you custom the whole thing to match I could see some advantages.

But I do agree if it is not broken then why fix it.
I've got a couple quibbles about it. First and foremost, I've seen that same wear on DI guns. Next, the impulse from a piston is probably sharper than DI, but significantly? I can see some difference, the DI gun has to fill more volume before achieving the required pressure to make the magic happen, but is the difference significant? Has there actually been any empirical testing on the impulse difference?

Lastly, I don't think the roller would even roll under normal operation. I can see it making a large difference when cycling it by hand, but when the gun cycles normally, seems like it would happen too fast for the inertia of the roller to be overcome and start rolling. Akin to a bowling ball, push it gently down the alley and it rolls the whole way. Give it a normal throw and it doesn't start rolling until it's almost at the pins.


Honestly I think the rolling pin is more of a gimmick purchase.

The same wear seen in piston guns is noticeable in DI guns, just happens faster.

Most who buy one are likely thinking it will reduce wear, however likely don't shoot their gun enough to even justify it.

I bought one for a piston gun. Did it need it, nope, gun ran fine before install, as did after.

There are a lot of gun owners who fear shooting their guns as if shooting them will ruin them somehow. Much like how folks ask for round count on used guns.


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