M1A barrel swap help

[weaver91]

Hi i have an M1A Scout Squad (18 inch barrel) and I would like to swap the barrel out to a standard length 22 inch barrel. Im hoping there is some one out there that can send a link to a how to guide or maybe a video link so i could do this myself.... i would like to learn this incase i desire to swap back the 18 inch barrel to shoot corrosive ammo or just play around. Thanks!

[Lethal_addict]

You need to really look into this carefully, head spacing requires precision and specific tools. If you do this wrong you could have catastrophic results. Best of luck with this!

[a308garand]

It takes a bit of knowledge and tooling to get the barrel installed right.

Mounting the new barrel is pretty much fitting the relationship between the barrel, receiver and bolt so that everything is within spec. As you shoot rounds, the parts wear into each other. When you fit another barrel, you start over again at square one with the fitting process.

There is no real guarantee that the long and short barrel will keep fitting the receiver and bolt the same way each time. Stuff wears out and dimentions change. I believe that after several swaps, you would quickly find one or more parts will require too much fitting to allow the other barrel to easily fit at a later date.

M1A and M1 Garand rifles have their barrels mounted much the same way. take a look here:

http://www.youtube.com/watch?v=jN9iSoIuUAU

http://www.youtube.com/watch?v=jbJKD0_XyrE

http://www.youtube.com/watch?v=fOfCH-XshEI

The 18" barrel is a great length, enjoy it as is.

[ar15barrels]

Hi i have an M1A Scout Squad (18 inch barrel) and I would like to swap the barrel out to a standard length 22 inch barrel. Im hoping there is some one out there that can send a link to a how to guide or maybe a video link so i could do this myself.... i would like to learn this incase i desire to swap back the 18 inch barrel to shoot corrosive ammo or just play around. Thanks!

You need a barrel wrench and an action wrench, chamber reamer and headspace gauges.
Detail strip the front half of the gun down to just the barreled action.
Un-thread the barrel from the action.
Ream the chamber of the new barrel for proper headspace.
Thread in the new barrel into proper index.
Reassemble the rifle.

[strongpoint]

The M14 Complete Assembly Guide

http://amzn.com/1888722169

[saki302]

I asked my buddy Randy @ R&D about this a couple years ago.

He could install the barrel no problem, but you need a pull-thru chamber reamer to do the final cut on the chamber which most gunsmiths do not have.

Since the M14 receiver is solid at the rear, standard chamber reamers do not work (won't fit, and you can't turn it if it did, at least not easily).

-Dave

[kendog4570]

... you need a pull-thru chamber reamer to do the final cut on the chamber which most gunsmiths do not have.

Since the M14 receiver is solid at the rear, standard chamber reamers do not work (won't fit, and you can't turn it if it did, at least not easily).

-Dave

This just ain't so. The chamber can be finish cut with the barrel either on or off the receiver, with either type reamer. As a rule, pull through reamers are armorers tools so privates can barrel M1's with a small amount of training.
Any one that really knows their way around these rifles can do it either way.

[saki302]

Don't you need to cut the chamber after the barrel is installed though, since the bolt locks onto the receiver, not the barrel?

-Dave

[ar15barrels]

Don't you need to cut the chamber after the barrel is installed though, since the bolt locks onto the receiver, not the barrel?

-Dave

You can check barrel timing into the receiver, then calculate the amount of shoulder crush for proper index, then subtract that from the gauge protrusion you need to end up at for proper headspace as measured to the bolt face from the receiver face.

[saki302]

I see now.

I forgot you are good with math, Randall

-Dave

[kcstott]

Don't you need to cut the chamber after the barrel is installed though, since the bolt locks onto the receiver, not the barrel?

-Dave

Remington
Winchester
Browning
Mauser
Sako
Savage
M1 Garand
M1A all have locking lugs in the receiver and everyone of those barrels is chambered off the receiver

See the trick to all this is the threads on these M1 and M1A receivers are timed. Something you don't se any more on production guns. So you can take a properly made barrel and install it to proper index and the headspace is correct
Little bit of math involved, and little bit of experience based on how much crush you get on the barrel steel. and how much the threads pull up tight.

These two guys just went over a longer thread about a Garand and I picked up some very valuable information.