Rehardened M3 Bolts

[jim c 351]

On page 88 of Frank Iannamico's book, The US M3 SMG, it is stated that Springfield Armory rehardened M3 bolts that were not properly heattreated at time of manufacture. Does anyone know how these bolts were marked after rehardening?

Thanks,

Jim C

[jim c 351]

On page 88 of Frank Iannamico's book, The US M3 SMG, it is stated that Springfield Armory rehardened M3 bolts that were not properly heattreated at time of manufacture. Does anyone know how these bolts were marked after rehardening?

Thanks,

Jim C

 

I posted this question last Nov. and received no responce.

I may have learned something during this time.

The US M3 SMG that I bought came with a Buffalo Arms 8/44 bolt and a SWK-GL #B301479 sear.

The sear notch on the bolt was very badly battered. It was so bad that a friend standing behind me while I was shooting could actually hear me pulling the trigger.

Last Nov I bought 2 M3 bolts on Gun Broker. Both were Buffalo Arms. A 1/44 and a 7/44. These bolts were identical to the bolt in my gun with one exception. They both had a "H" stamped on the top right side of the bolt , visible thru the ejection port. I immediately wondered if the "H" might stand for heattreated or hardened.

 

I installed the BA 1/44 bolt in my M3 and fired several hundred rounds, Half of which were single taps. There was no battering of bolt but the sear was roughed up.

Next I ordered a late type, wide engagement, sear #7162774 from Numrich.

With the new sear installed I fired 600 - 700 rds and noticed no battering of the bolt sear notch or the new sear.

 

How many of you M3 shooters have a bolt with a "H" stamped on it?

How many of you have the late type sear?

What is the condition of your bolt sear notch and sear?

 

Now a change of subject. In Frank I's book an American subguns he mentions stress cracks at the rear of receiver.

Since such talk makes me nervous I tried to come up with a buffer. I ended up tracing the locater plate on the flat part of a plastic 1 gal milk jug and cutting it out with sissors. I punched 2 holes in it and installed it between the the locater plate and the receiver. I don't know how much good its doing , but after 700 rds its still intact.

 

Lets hear what you guys think.

Jim C