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Posted: 6/23/2012 8:55:55 AM EDT
| With all the piston variants of the AR platform floating around, it got me thinking has anyone ever tried to develop an AR using the roller locker principle like the MG-42 and G3? It should be more accurate than most piston guns and it also keeps the carbon out of the action. |
| HK93 is 5.56 NATO. As stated, roller locking is a bit dirtier in the chamber area. In my experience with a HK91 (7.62) is it dirtier, hard on brass (when you can find it). That said, it runs fine with no functional issues that would choke an AR. My AR is much more accurate, the HK more reliable in dirty conditions. YMMV |
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Carbon residue inside the receiver of an HK or CETME is virtually a non issue because of the loose tolerances of bolt carrier to receiver. A toot of brake cleaner every so often followed with a shot of Mobil 1 and you're in business.
Light/Heavy, that's relative. Choose your comfort level here. |
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Quoted:
it also keeps the carbon out of the action. Roller locked rifles like the HK types are the dirtiest actions you will ever see in your life, far worse than the AR. Quoted:
A roller locked AR, would be more accurate than the HK rifles as it would not have a cocking tube disturbing the barrel harmonics. The barrel could be free floated. You're making no sense with this line of thought. For one thing, a "roller locked AR" would no longer bear any resemblance to an AR. Second, the general level of accuracy of the AR platform is partly/largely due to the consistency of the multi lug bolt lockup and compact design of the bolt/barrel/barrel extension, all of which is out the window with a roller locking (actually roller delayed blowback) system. Most roller locked rifles have free floated barrels. |
| For 9mm I really like the roller delayed blowback system of the HK Mp5. But for 5.56mm and 7.62mm I prefer a gas system. But yeah it would be cool to have an upper than could turn your AR-15 into an Mp5. Of course this would make the weapon a lot larger, since you would basically have the Mp5 receiver sitting on top of an AR-15 receiver. I think those with an M16 lower might have interest in this, but if just looking for a semi-auto you can pick up a Mp5 clone fairly cheap. |
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Quoted:
A roller locked AR, would be more accurate than the HK rifles as it would not have a cocking tube disturbing the barrel harmonics. The barrel could be free floated. Other than a heavier bolt assembly, what would make the rifle heavier than any other AR? HK roller guns (G3/HK91/HK93/HK53 etc.) are free floated. The cocking tube doesn't touch the barrel, and the handguard attaches to the cocking tube and receiver. The carrier on roller-delayed blowback guns is heavier to assist slowing unlock. |
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This is too funny. I had this exact conversation with a friend of mine concerning a roller locking AR. If roller locked, what are the rollers going to lock in to? The aluminum upper? I don't think so Tim. You could make the barrel extension extended to the rear for the rollers to lock into that. That should prevent the rollers from damaging the aluminum upper. But look at the cost you are going to add to have to have the barrels fluted. And the flutes have to be the proper number, size, length... you just cannot scratch a few lines in there, call it fluted and expect it to work. Look at the mass of an HK bolt carrier compared to an AR carrier. Not to mention the roller mechanism is considerably more complicated than the DI system and much more expensive to manufacture. Is it any wonder HK has all but abandoned the roller locking system on their new rifles? And lets not forget the timing issues that develop if the bolt gap is not correct and the damage that can happen if too large or too small. If you think replacing a gas ring is complicated just try to replace the rollers. If roller locking were a game winning platform, HK would have used it in their HK416 and 417. They did not. They went gas piston and look at how everyone has followed. HK even dropped the roller locking from their pistols in favor of the less complicated and much cheaper to manufacture modified Browning recoil operated tilt barrel system.
Can it be done, I am sure it can. But look at the cost and the engineering that is going to have to go into it. Simple it will not be and it is going to be a money pit before you get one operating correctly. Better to stick with DI or GP ARs, at least for now. |
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what Quoted:
A roller locked AR, would be more accurate than the HK rifles as it would not have a cocking tube disturbing the barrel harmonics. The barrel could be free floated. Other than a heavier bolt assembly, what would make the rifle heavier than any other AR? what is wrong with DI accuracy? how is a roller system going to improve it? really overcomplicating to solve a minor problem that is better addressed with much simpler solutions. If you want rollers, go with an HK-33. DI is the whole point of the lightweight AR-15 this is very COD 
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Quoted:
Replacing rollers is easy as hell. It mounting the bolt back to the carrier that is a bitch. It is just the opposite for me. I have no trouble at all getting the bolt back in the carrier, but the one time I have done the rollers I had a real time of it. Likely because it was my first time doing it. But I have done the bolts enough that if there is a trick I suppose I have learned it. Regardless, there is nothing hard about replacing any part of an AR carrier/bolt. I think we can agree on that. Please don't tell anyone who has a $14,000 PSG-1 that the cocking tube makes their rifles inaccurate. They would laugh in your face then shoot your eye out. 
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This would be a step back in my opinion. No advantage in accuracy dept. Overcomplicates headspace process. On the HK when you run out of bolt gap adjustment that can be done with new rollers, barrel needs to be repressed.
Long story short, if they came out with a roller locked AR I'd never touch one personally. |
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