Swapping Bolts between Uppers

[switch625]

Can you swap the b/bc/ch around between two uppers with no problems?

[RMTactical]

Yes, you can, but I wouldn't make a habit of it.

[switch625]

C'mon man, walk me through it.

[Onmilo]

Yes, no, kinda-sorta.
In theory a bolt/carrier should interchange between uppers but with sooooo many aftermarket producers out there do you really want to take the chance something may or may not work safely without checking dimensional compatability with a set of headspace guages???

[Big Bird]

99 times out of 100 it will... To be safe...spend $25 on a USGI "Field" guage and you'll know for sure...

[USMC03Grunt]

The offical answer is no. However, we have ran across some M-16A2 conversion rifles in a few mobility boxes and in the armoury that had chrome bolts and carriers. By Air Force standards, these weapons are non-deployable. However, we were able to swap out a few parts with old M-16s and M-16A1s that did have the black bolt with the forward assist serations without any problems. However, if you do this (and I'm NOT suggesting you do) be sure to re-check the headspace any time you replace a barrel or bolt.

[Sierra]

I agree. Unless you know what you are doing its bad ju-ju.

[switch625]

Saw this over at arfcom, makes the most sense of what I've seen so far. He is speaking of replacing a barrel though.



http://www.ar15.com/forums/topic.html?b=3&f=4&t=226782

"Q3. What about checking the headspace after I assemble?

A3. While checking your headspace is never a bad idea, it isn't required for this operation. The headspace of an AR is set by the bolt's fit into the barrel extension. As long as you are using a good quality bolt and barrel, that was headspaced by the manufacturer, you are good to go. If you are assembling very old/used barrel/bolt, then you might want to consider checking headspace. Changing the barrel has no bearing on headspace, because the barrel's seating in the upper receiver makes no difference, it is all in the bolt and barrel extension."


The reason I ask is I'm keeping the b/c/ch out of a NEW upper, selling the upper and ordered a different NEW upper minus b/c/ch. Since both uppers have been head spaced I'm sure I'll be ok.

I was considering using two different uppers and one b/c/ch, but I'm not anymore.

[RMTactical]

You'll be fine to keep your old B/BC for your new upper.

[OutintheWoods]

If both bolts are within spec and not excessively worn, yes.