ar15 bolts

[BUCK29]

I read or heard that you should not swap bolts in ar15s or m16's. I am looking at buying some uppers but would like not to have to buy all new bolts for them. Is there a problem swapping bolts from a used upper to a brand new upper.

Thanks,
Buck29

 

[tommygun2000]

I've heard this also, and I think its the biggest crock of bull I've ever heard.

What I don't understand is, How can you have interchangeable parts that "don't interchange"?

If these bolts were not supposed to be interchanged, they would be sold as "matched pairs", matched with a barrel. They would be numbered so as not to get mixed up.

While in the service, we dumped all the parts(from 12 rifles or more) into a tub of solvent, cleaned them and everyone picked back out what they needed to reassemble their rifle. Nothing ever happened to anyones rifle on the range.

I say go for it. Thats the theory behind "interchangeable parts".

 

[Brian Ski]

I think the idea was not to swapp AR15 parts with Full auto M16 parts. The bolts are interchangeable. (Meaning that a M16 bolt will work in a semi, not the other way around) The difference is the AR15 bolts have the bottoms milled away so that a sear cannot engage with them.

The problem lies when you have full auto parts in a semi auto, you are starting to cross into a grey area. The ATF is trying to prosecute people with full auto parts in a semi....

The parts that are different (but interchangeable)(not legally) are the bolt, trigger, disconnector and a couple others.

 

[RoverDave]

I've heard the claim too and it's not about the legality of full auto parts. Some claim that there are headspace concerns if you start swapping bolts. I also think it's a crock.

 

[carcass]

I'm pretty sure the claim was made based on a headspace issue, however, the AR-15/M-16 headspaces based on the bolt-to-barrel extension contact. The only way to adjust the headspace is to move the barrel extension back and forth, as far as I know.

A badly worn bolt or extension, or combination of less wear on both, can cause headspace problems. I'd say just check the headspace with a go/no-go gauge; if it's go, then use it.

The only other thing I could think of was upper-to-bolt carrier wear, but since the bearing surfaces are very small, I can't see it being much of a problem. I think if your upper or carrier is worn enough that it rattles around when assembled, you have bigger problems...

 

[tommygun2000]

I think the idea was not to swapp AR15 parts with Full auto M16 parts. The bolts are interchangeable. (Meaning that a M16 bolt will work in a semi, not the other way around) The difference is the AR15 bolts have the bottoms milled away so that a sear cannot engage with them.

The problem lies when you have full auto parts in a semi auto, you are starting to cross into a grey area. The ATF is trying to prosecute people with full auto parts in a semi....

The parts that are different (but interchangeable)(not legally) are the bolt, trigger, disconnector and a couple others.

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I understand the issue you are talking about Brian but its the "bolt to barrel" ....the head space issue that is the safety thing and I don't think it has much merit myself. I have swapped bolts out in a couple of different ARs and theres been no change in function in either of them.
The carrier is the legal issue of "constructive possession"..which is in itself another crock of shit put forth by the ATF.

 

[BUCK29]

Thanks for all the responses. I thought it was B.S. myself but wanted to get some other opinions.

Thanks,
Buck 29

 

[kanewtervalve]

I've built a bunch of ARs and swapped bolts all the time(whenever an issue with FTF,FTE, etc) and never had a problem, all semi. Headspace with ARs is an old wives tale, especially since a well known gunsmith told me so.

 

[Brian Ski]

I read or heard that you should not swap bolts in ar15s or m16's.

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I understand the issue you are talking about Brian but its the "bolt to barrel" ....the head space issue that is the safety thing and I don't think it has much merit myself. I have swapped bolts out in a couple of different ARs and theres been no change in function in either of them.
The carrier is the legal issue of "constructive possession"..which is in itself another crock of shit put forth by the ATF.

TG... I took his first sentence as swapping between the AR15 and M16.

As far as the same series, Unless some custom work was done, they should interchange since they are mass produced...

 

[Deadline222]

heh

I have an M-16 flash supressor on my AR-15. :cool

 

[cookie]

I have GO, NOGO, and FIELD headspace gauges for 5.56 that I use for my ARs. Military chambers are "looser" than commercial chambers, therefore a new AR bolt & barrel combo will often close on a NOGO gauge, but it's no problem. If they eventually (after lots of use) close on a FIELD gauge, then you'll need to replace the bolt or barrel.

If your used AR bolts are OK with your old barrels, they'll almost certainly be fine with your new ones.

 

[jwp]

agree in most cases swaping doesn't hurt but checking with gages is smart ie blasting my m16 or plinking with ar15

that said i have several ar target rifles for nra hipower competition and these have the bolts lapped to the bolt extension and minimum headspace - i would never interchange these bolts