little gunsmith info

[haustinv]

I have a bolt carrier that I want to put a POF roller cam pin in. The trouble is I need to remove the gas key screws to install the modified gas key that the roller requires. The staking only pushed metal against the screw heads not over their edge. I thought that even though the screws were staked this way they could be broken loose and though difficult backed out. Only problem is they won't even break loose. Anyone have any suggestions.

[terrywick4]

I used a dremel to get rid of the stake and then heat to break the loc-tite

[LRRPF52]

I have a bolt carrier that I want to put a POF roller cam pin in. The trouble is I need to remove the gas key screws to install the modified gas key that the roller requires. The staking only pushed metal against the screw heads not over their edge. I thought that even though the screws were staked this way they could be broken loose and though difficult backed out. Only problem is they won't even break loose. Anyone have any suggestions.

I just started with a new carrier, a chromed one, to be exact, so it would match the POF key and roller cam. I'm not so sure the roller cam adds any benefit to the system, since you have a single point of bearing from the roller, versus a flat surface from the standard cam pin.

Colt actually was putting this on the AR-10A back in the 1959-1960 time period, and had tooled up to start mass-producing AR10A's. When they received word from their marketing partners to stop production on the AR-10A, and start cranking out AR15's, the die was cast for the future. This was in response to the reception that the AR15 was getting over the AR-10 during the world tour demonstrations being done at the time, especially in the Asian Pacific region.



Are you attempting this modification on a chrome or phosphated carrier? Doesn't really matter, just asking.

[cory]

Is a different cam pin really worth all of that trouble?

[montana]

I have read that the roller bearing prevents ware on the inside of the upper receiver camming channel but I think this would only be necessary with a gas piston set up.

[haustinv]

I have the Mega billet SBU upper, matching billet lower and am using a JP stainless full auto, full weight carrier. I want the roller for the reduced wear on the cam channel in my upper. I know with a standard cam pin there is an initial wear pattern created upon first break in and that it normally stops or slows way down from there. I got a real good deal on the roller kit. I am a little anal sometimes about things being just right and just don't want the wear when it can be prevented. I am even having my upper NiB-X coated by WMD. Just like the idea of the reduced friction and wear.

[cory]

Do you have the tools to restake the carrier properly? IMHO A loose carrier key would give you much more problems than a cam pin.

[Tedward]

I looked in my SBU uppers and others and don't notice and contact from my cam pins. I think montana might have a point. Aren't POF all piston systems?

[LRRPF52]

I wouldn't attempt to disassemble the JP carrier & key unless you have a proper staking tool, torque wrench, drivers, new Grade 8 fasteners, acetone, Red Loc-tite, and detailed knowledge of how the carrier key to bolt carrier mating is supposed to work.

The most important things about the carrier key are:

* Solid gas seal with no chance of leaking (JP knows how to get this right. They are one of the few in the industry)
* Proper alignment of the carrier key with the gas tube (Most companies haven't a clue about what this really means in the AR, and don't really care.)
* Hard chrome lining of the carrier key. Most companies are oblivious to chrome-lined keys, and almost all are ignorant of the surface hardness the outside of the carrier key is supposed to be. I was ignorant of it until last year, and it's softer than I would have thought for a reason.

If you're going to do it right, you need specific tools for it, and need to be able to clean out the threads in the carrier for the fasteners, as well as fully degrease the carrier. It needs to be bone dry before installing the new carrier key, with new fasteners.

http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/staking-tools/ar-15-m16-carrier-key-staking-tool-carrier-key-staking-tool-sku080-000-638-29337-55683.aspx

The only reason I have a POF roller cam kit is because Frank was handing them out as promotionals at SHOT a few years ago. I installed it in a Young's MFG chromed bolt carrier for one of my retro projects that is meant to be a sleeper (1963 on the outside, 21st Century on the inside). I have yet to shoot it, as the build is years in the making, and not a top priority for me.

I do find it interesting that Colt had the roller cam on the AR10A, which was really Armalite and the Dutch's combined work on taking the AR10 to the next evolution for production.

[Kohoki]

Is a different cam pin really worth all of that trouble?

Definately not! That roller cam pin is not an enhancement but a part which can brake and cause trouble.

[LRRPF52]

The thing that bothers me about the POF roller cam is the rivet holding the roller to the body. Will it hold up?

I know regular cam pins work, so...