Garand Barrel Timing

Howdy, new guy here with a Garand style project going on. How did the factory time the barrels on M1 and M14? Did they just leave the face of the receiver full and then mill it unitl the barrel timed correctly after torquing?

The only alternative I see is leaving the receiver face nominal and the barrel "plain", torquing the barrel, and then adding details to the barrel.

Can't comment directly on the Garand, but the link to US Rifles & Machine guns posted a few pages back shows the fixture used for milling the threads in '03 Springfield receiver rings. It has a small cutter mounted eccentrically on a master thread.

It also discusses the guaging at all stages of manufacture.

Late production No4 Lee Enfields used a small pack of peel off shims on the front of the ring to get the extractor slot to line up exactly and to allow for manufacturing tollerances, but they had the advantage of headspace / head protrusion adjustment with interchangeable bolt heads, which you don't.

hope that helps some

Keith

What kind of barrel are you putting on? I have never seen a case where anything had to be done to the face of the receiver. DO NOT touch that part.
The torque shoulder on the barrel depends on who you got it from. I am not aware of any current manufacturers that require you to set the shoulder back. It should hand tighten to within about 20 degrees or so and then you wrench it around the rest of the way. I forget the exact spec for torque but I think it was at least 80 foot pounds required to remove it.

They used gauges; on both parts. Reason for that is that you had several different manufacturers, over a period of years. A 1941 Winchester BBL would fit on a 1958 SA frame etc. Frames and barrels that were out of spec were scrapped. I'm assuming that the frame is US Surplus, if so then it was already gauged at the time of manufacture; I would not mess with the receiver face.

If you’re making a new BBL for a Garand, then thread the BBL, get proper headspace w/BBL properly torqued, and then machine the other cuts.

Mike Hunter
www.Hunterrestorations.com

Thanks for the info. Sorry, I should have clarified what I'm planning to do. The project will be a custom receiver (w/ Garand style action) and a new barrel that I will turn and thread from a blank.

I get what you're saying on the interchangeability. With the M1 and M14 receiver and barrel 100% pre-made, without matching a particular barrel to a particular receiver, I could see the need for lots of gaging. Not ony would receiver length and barrel shoulder have to be gaged, but I guess the recv and shoulder threads would have to be "timed". The thread lead-in would have to start at the same place on every part. Is that how they did it?

That would be difficult for the homebuilder to develop all those gages or fixtures, especially for the threads.

So I could either leave the recv face full, totally complete the barrel and then face off the receiver until the barrel timing was right. That would require a short-chambered barrel, of course. A similar approach would be to adjust the barrel shoulder and thread length.

Or I could leave the receiver alone and use fixturing to locate oter barrel features (gas port, op rod guide,etc.) after torquing the barrel in place.

What would be your favored method?

Ok so let me get this straight… You’ve got a custom receiver i.e. casting or machined from a forging or bar stock? But not a reweld.. is that correct?

And your barrel is a barrel blank.

True up the face of the receiver, and then figure out how to thread it. Probably the best way is with an angle plate on a milling machine, bore out the barrel hole and thread with a tap. Since I don’t know what you have, squaring the frame to get the barrel hole bored true is up to your imagination.

Thread barrel, and start measuring headspace, once you get headspace correct. Make the other cuts, holes etc on the barrel. If you have a “true” spot on the frame you can machine most of it with the receiver in place, using the receiver as a reference.

But that’s just my thoughts, I sure there are folks here with a lot more experience.

Mike Hunter

I would finish the receiver first, then thread the barrel. Screw the barrel into the receiver and use it for the fixture for the remaining barrel machining processes. You might leave the receiver with enough material for a good hold for the barrel machining process, then finish machining the receiver. Depends where heat treating fits in and what kind of tooling you have (whether you can machine the receiver in its heat treated form.)

When you fit the barrel, you should have the gas port drilled already and use its location as an index point. The best results are with the gas port centered in a rifling groove. If it is in a land or on the edge of a land, you will end up with copper fouling in port and faster port erosion. We use a borescope in our shop to help center the port.