New Old Guy, with a question

[11B40]

Hello Folks, a brief Bio. New to M1s, old both in age and the use of firearms. I may get into a good story thread about headspace in M2s MGs and WWII foreign rifles, but that will wait for now. I recently bought two fine rifles from a friend. One a Smith Corona 03A3 and the other a IBM 3939xxx M1. I figure I'm the fourth owner (counting the Govt.) as I got the original paper work from the NRA when it was purchased in 1964 for $20. From what I have learned it was redone by Underwood by the stock stamps and the mis-matched parts. My plans are to slowly make it as correct as possible. My question is what material is used in making GO, NO-GO, and FIELD gauges. Since my budget is tight I would rather spend on parts and use my lathe to make the gauges.
Thanks Much
wayne

My Life, Past & Present!
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[Tired Retired]

I am not a machinist so I do not know what the standard metal content is for gauges. However, I think that it would be up to each manufacturer (forster, cylmer, etc) as to what they choose to use. I have been able to shop around and get all three gauges for about $75 total. If you want to do it yourself, I am sure that any barstock you use would work - its for your own uses.

Just my two cents worth...

[JimF4M1s (Deceased)]

Once your machine is set up, they should go fast. You might want to make a few of each. Could be trading bait for some parts.

My 2¢

[manteo97]

If you are just using these gauges for yourself, a free-machining brass would work OK. If you can't get free-machining, then a 70-30 cartridge brass rod would work too. If you want to go with steel, a free-machining steel would be best like a 12L14.

[CrossedCannons]

If your budget is tight, you might also consider buying only a chamber length gauge for about $5 at Brownells. It's like an "adjustable" headspace gage. You load it into the chamber, slowly close the bolt, remove it from the chamber and measure it. No GO, NOGO, or FIELD gage necessary, you get an precise measurement! You do need access to reloading equipment (a simple hand press and dies will due) or somebody that does though to "rebuild" the gauge each time you use it to measure headspace.

[11B40]

Thanks Folks, and Crossed Cannons gave me an idea. I will machine up a set of gauges using old (SWG) .valve stems. Now for the idea, how does this sound. I have rebuilt many engines in my life and after using a Micrometer on the crank journals I still did a final check with Plastic-Gauge. It is plastic rod that is made to flatten, you then measure the flattened piece against there paper gauge and you get the clearance in thousands. I may give that a try with a stripped bolt on my Underwood IBM rebuild and when the gauges are made see how close I come to the same result.
Quick story on head space. When I was 14 my Dad took me to a local department store for my first deer rifle. They had 6.5 Carcanos in barrels for $9.99 (ammo was $1.49). That was when NY was still part of America, I'll be 65 in Feb. My Dad picked out a good one for me but didn't like the bit of surface rust on the bolt. Yup, you guessed it He switched bolts with another rifle. I shot that rifle right up till I went into the Army, there I learned about head space and timing on the M2s. I remembered people who saw the rifle firing telling me a flame always shot out the side. After the Army I made a No-Go gauge by soldering a piece of brass shim stock to a fired case. It closed as easy as it was empty! I threw the bolt away and the rifle is inside a wall of a house I used to live in.

[USGI]

Plasti-gauge might work, but may get messed up when the bolt turns. Kind of like turning the crankshaft while checking bearing clearance. I couldn't find the Brownells gauge mentioned by Crossed Cannons - tried searching their site a couple different ways. - Bob

[CrossedCannons]

USGI, sorry about that, I thought I bought mine from Brownells, years ago, but maybe not (growing old sucks). They handle Sinclair's products. Here it is

Sinclair Chamber Length Gage - Sinclair Intl

[USGI]

CC: I think most of us here are in that same boat! Thanks for the link. - Bob