12-24-2013, 05:02 PM
6061 Aluminum is a great alloy for certain climbing components, where the ductility of the alloy does well with loads and impact, like the weight of a climber falling and being stopped by connections.
The DPMS Claw receiver insert tool was meant for their Lo-pro Classic that came out back in the day, where they were able to source cheaper alloys, low-end components, and easier tool time to offer an AR15 for $630 retail. 6061 is easier to cut, being softer, and as mentioned, it's cheaper. They also got rid of the ejection port door, forward assist, and used a bull barrel that didn't require complex and timely profiling. Slap on a 6061 gas block, and call it good.
Anyway, the 6061 will flex more, so they are less likely to break, but will still distort under torque from the tool. If you true a thick 6061 upper, preferably with a tight extension tunnel, it can make a nice foundation for a heavy barrel or lighter gun, but impact resistance can be a different ball game, and if the anodizing isn't done deeply, I have seen a lot of flaking on them.
The benefit to 7075 T6 is that it has significantly more tensile strength than 6061, and in the AR15, receiver mate-up is better achieved with 7075 versus 6061, as the pivot pin and takedown pin lugs and bosses will wear faster with 6061. Where 6061 makes more sense is in the handguards, if using aluminum.
What I have experienced with a 6061 receiver set when using dynamic tension with a 2-point quick adjust sling is that a really nice, tight receiver fit has been worn loose. The 7075 T6 billet sets from top-end manufacturers are the ones to beat in this area.
The DPMS Claw receiver insert tool was meant for their Lo-pro Classic that came out back in the day, where they were able to source cheaper alloys, low-end components, and easier tool time to offer an AR15 for $630 retail. 6061 is easier to cut, being softer, and as mentioned, it's cheaper. They also got rid of the ejection port door, forward assist, and used a bull barrel that didn't require complex and timely profiling. Slap on a 6061 gas block, and call it good.
Anyway, the 6061 will flex more, so they are less likely to break, but will still distort under torque from the tool. If you true a thick 6061 upper, preferably with a tight extension tunnel, it can make a nice foundation for a heavy barrel or lighter gun, but impact resistance can be a different ball game, and if the anodizing isn't done deeply, I have seen a lot of flaking on them.
The benefit to 7075 T6 is that it has significantly more tensile strength than 6061, and in the AR15, receiver mate-up is better achieved with 7075 versus 6061, as the pivot pin and takedown pin lugs and bosses will wear faster with 6061. Where 6061 makes more sense is in the handguards, if using aluminum.
What I have experienced with a 6061 receiver set when using dynamic tension with a 2-point quick adjust sling is that a really nice, tight receiver fit has been worn loose. The 7075 T6 billet sets from top-end manufacturers are the ones to beat in this area.