AR Sponsor
Posted: 12/23/2004 2:00:56 PM EDT
|
Hello everybody! How dangerous is bolt/bolt carrier swapping between different ARs? When they sell complete uppers without bolts they say that upper has been head spaced…. I think I understand what that means … and ‘put your bolt in, attach to lower and rock-n-roll’.. Now , on the other hand when they sell uppers with bolts they say that bolt has been head spaced for this upper…. So…. Bushmaster web site says that they do not recommend swapping bolts…. I am confused… Is it safe to buy separate uppers and bolts and then join them with lowers into complete rifles? Thanks, Tim |
| Here's how it works: they put the barrel extension in, and headspace it to something akin to a bolt. Then they pin it and do the next barrel. Since they make all their bolts, and their headpacing tool, to the same dimensions, you're good to go. To BFI it is a liability issue, in case their rifle blows up. Some barrels are headspaced to the actual bolt you get, for accuracy. Compass Lake Engineering (MSTN SPR barrel supplier, IIRC) sells them like this. |
|
Read the tacked threads, they're there for a reason: Headspace, Torque values, and Barrel Break-in |
| The bolt will lap it's self to the extension. I would say if your concern is about accuracy, then stick with the bolt that you've been using with the barrel. If you have a head space gauge then you can put the bolt in another barrel and check it. You should be ok. Again if you shoot the bolt alot with one barrel, it will be mated to that barrel. If I needed to shoot a different barrel, in a pinch I would do it. I would however check the head space with a tool. Just my .02 worth. |
| The bolts and barrel extensions develop wear patterns to each other. Fitted bolt just means minimum or a set headspace for each individual bolt head. If you have a fitted bolt/barrel, then keep them together because the next bolt head might be tight enough to cause functioning problems. It was put together that way for accuracy with reliability. Standard barrels are chambered looser for reliability and so you could put any bolt in them and have it headspace correctly. Basically, unless you have a fitted bolt, you can switch bolts out. I wouldn't do it because it would accelerate wear, but it is doubtful that you would ever have a safety issue. |
AR Sponsor