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Posted: 2/5/2009 5:52:49 AM EDT
| Please help me remember-what's the rule on switching BCG's from one upper to another. Can I put a slightly used(less than 100rnds.) BCG that I had in one upper into another new upper. Or is that a no no. Thanks! |
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Bolts SHOULD have the headspace checked when being exchanged. Bolt carriers don't effect headspace one way or the other.
You'll probably never find a bolt that's out of spec, but they are your eyes. Me, I check headspace whenever I change bolts, like the TM says. I've never found one that was out but there is always a first time. BSW |
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Who made the parts doesn't matter. Any manufacturer can have a bolt that, in combination with another manufacture's barrel assembly, will be out of spec.
Why headspace is important. 
How to check it. Yes, you need a FIELD gage. Someone in your hometown forum probably has one already. 
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| As stated, you should be GTG, though I respect BST's statement of caution. My problem with guages isnt the do or dont, rather the difficulty in finding actual 5.56 instead of the much more common .223 such as Brownell's sells. If you have access to the correct guages, by all means use them. |
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Quoted:
You'll want one bolt for every barrel. As you shoot the rifle the bolt and the barrel will wear together, more or less making a matched set. Swapping a carrier is fine but keep the bolt and barrel paired up. This is what I have seen posted by those who would know. |
| Thanks again for all the reply's. The LMT bolt I have will be only used with this new upper. It was on a new Sun Devil upper i had(100 rnds shot) until I got lucky and grabbed one of the BCM uppers that went up for sale this morning. I didn't want to let the LMT go with the Sun Devil being their so damn hard to find these days. |
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Quoted:
Bolts SHOULD have the headspace checked when being exchanged. Bolt carriers don't effect headspace one way or the other. You'll probably never find a bolt that's out of spec, but they are your eyes. Me, I check headspace whenever I change bolts, like the TM says. I've never found one that was out but there is always a first time. BSW Ding ding ding! This is the only correct answer to the OP's question. I always check headspace, and I have found one brand new bolt that would not work on one occasion - it was an LMT  . Fortunately, it would not close on a "GO" gauge which is probably less dangerous than the other way around (too much headspace) - although I suppose firing slightly out of battery might have been a risk.
Check headspace. Shit, this comes up way too much around here and people get the "You're good to go" answer way too many times. Bushmaster sells proper sets of 5.56 headspace gauges. It's expensive, but if you do it enough I won't be surprised if you find one that is off. |
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