PDA

View Full Version : Bolt Swap


ky hunter
September 20, 2012, 07:35 PM
Is it OK to swap AR 15 bolt, bolt Carrier & charge handle from one upper to another? Is this common practice?

Creeper
September 20, 2012, 07:59 PM
Yes... oddly enough, it is common. Doing so however may not be very good for the locking lugs of the guns and bolt you are switching around with.
Locking lugs will "break in" and develop light wear patterns. You start swapping things out and back and forth, and you may not get a good, square and true lock-up of the bolt and barrel extension lugs. Doing so may also be detrimental to the guns accuracy and may accelerate wear on the measured chamber length.

In a high end match target AR, the bolt is matched and lapped in to the barrel extension and barrel to ensure 100% square and true lock-up... much like a 'smith would lap in the locking lugs of a bolt action target rifle. There is one that I'm aware of, and possibly more AR barrel makers, who actually sell their barrels with a new, matched bolt included in the deal.

IMO... I would suggest, at least, having a bolt for every upper assembly or barrel you use. But then of course, you now have wear issues between bolt and carrier... so where does one draw the line eh? :p

If super accuracy is not a concern, and you tend to replace bolts as a wear item anyway... nothing I've said really matters all that much.

C

greentick
September 20, 2012, 08:14 PM
If the parts are used, ie taking a used bolt/BCG from one rifle to another, you will probably want to get the headspace checked.

Creeper
September 20, 2012, 08:19 PM
you will probably want to get the headspace checked

Ha ha ha. Very good greentick... sometimes (most of the time?) I forget the most obvious and necessary things. :p

Cheers,
C

ky hunter
September 20, 2012, 08:32 PM
It was just A thought haven't tried this.

greentick
September 20, 2012, 10:08 PM
...Very good greentick...

sometimes I actually surf during normal waking hours and produce cognizant thoughts...:D

Creeper
September 20, 2012, 10:29 PM
Somebody's got to do it...

madcratebuilder
September 21, 2012, 08:54 AM
The 23&P discusses this in some length. Used bolt in new barrel, new bolt in used barrel are acceptable. Using a used bolt in a used barrel are not approved. Both the bolt lugs and BE lugs well have a established wear pattern on used parts that may not mess together well resulting in rapid wear of the lugs. Used parts that meet headspace check could wear past maximum headspace fairly quick...in theory.