Jump to content


Photo
- - - - -

Weight variation for M1 Bolt?


  • Please log in to reply
9 replies to this topic

#1 imageaudio

imageaudio

    Long Time Member

  • Board Benefactor
  • 54 posts
  • Gender:Male
  • Location:Texas
  • Interests:I enjoy collecting WW2 guns, original period literature and memorabilia.

    I reload ammo and participate in competitive shooting. I also do very minor gunsmithing.

    My primary objective in all things is safety first.

Posted 30 October 2019 - 12:02 PM

Wondering if anyone has the specifications for what the mil spec weight range would be on an M1 bolt?    Or stated another way, what's the acceptable level of weight variation?    I think the average bolt weights approx 1 pound and 12 ounces.   How much could that be varied plus or minus before you would begin to damage your receiver?

 

I went to the NFAtoys sight but unfortunately, they don't have a diagram for the M1 bolt.

 

Im not trying to create a speed bolt here folks.  600 Rounds Per Minute makes me happy.

 

 


  • 0

#2 Bridgeport28A1

Bridgeport28A1

    Respected Member

  • Board Benefactor
  • 1284 posts
  • Gender:Male
  • Location:USA

Posted 30 October 2019 - 05:41 PM

Some reading for you until someone weighs their M1 bolts.

http://www.smallarms...idarticles=2163

Only variation in a USGI M1 bolt would be a sand/mud cut bolt versus a standard M1 bolt. I wouldnt think there would be any weight difference between a bright versus blue versus parkerized finish bolt.
  • 0

#3 imageaudio

imageaudio

    Long Time Member

  • Board Benefactor
  • 54 posts
  • Gender:Male
  • Location:Texas
  • Interests:I enjoy collecting WW2 guns, original period literature and memorabilia.

    I reload ammo and participate in competitive shooting. I also do very minor gunsmithing.

    My primary objective in all things is safety first.

Posted 30 October 2019 - 07:17 PM

Thanks for info Bridgport28A1.    Great read.   Isn't it awesome that so many of the Small Arms Review articles are now online.  While no specs are given in Frank's article, the weighing of his bolts seems to indicate the Military Specifications need to be 1 pound 11.5 ounces.    

 

Quote from Frank Iannamico Article

 

"I used a recently calibrated postal style scale calibrated in ounces. Surprisingly, every M1 and M1A1 bolt checked weighed almost exactly the same at 1 pound 11.5 ounces. The only variation was that two of the M1 and M1A1 “bright” bolts were 0.25-ounce lighter than the others."

 

I have weighed the 2 bolts I own.   One is an M1 parkerized bolt which weights in exactly at 1lb, 11.5 ounces.    The other bolt is an M1A1 bolt with fixed firing pin in a blued finish.   It weighs in at 1lb, 12.3 ounces.    This bolt is an interesting example because it does not have either a Savage nor an AOC stamp on the rear flat.    My best guess is that it is a West Hurley bolt?    

 

I'm wondering if this heavier unmarked bolt could damage my M1 if fired extensively in the firearm?

 

The other question I have is regarding the cuts in the M1 parkerized bolt.    Is this what you are calling "Sand" or "Mud" cuts?   Or do you think the milling was done to get the bolt to the correct weight of 1lb, 11.5 oz?    See attached pics.

 

Would appreciate others weighing their M1 bolts and adding to the data.

 

 

Attached Files


  • 0

#4 Bridgeport28A1

Bridgeport28A1

    Respected Member

  • Board Benefactor
  • 1284 posts
  • Gender:Male
  • Location:USA

Posted 30 October 2019 - 07:23 PM

The bottom bolt in your photos are what are referred to as sand-mud cut bolts. Not a USGI term but one that seems to be used by collector to identify that style of M1 bolt.
  • 0

#5 PK.

PK.

    Technical Expert

  • Board Benefactor
  • 1578 posts
  • Gender:Male
  • Location:CO, USA
  • Interests:Full time gunsmith who loves Thompson's, 43+ years experience.

Posted 31 October 2019 - 09:03 AM

Your unmarked bolt may well be a WH, in which case you do not want to run it; cut it in half.


  • 0

#6 Bob

Bob

    Long Time RKI Member

  • Board Benefactor
  • 733 posts
  • Gender:Male
  • Location:Wa. and AZ.

Posted 31 October 2019 - 09:14 AM

This is what I get on my postal scale. All are "S" bolts top to bottom, "sand cut", "sand cut" bright, M1A1, M1.

Attached Files


  • 0

#7 imageaudio

imageaudio

    Long Time Member

  • Board Benefactor
  • 54 posts
  • Gender:Male
  • Location:Texas
  • Interests:I enjoy collecting WW2 guns, original period literature and memorabilia.

    I reload ammo and participate in competitive shooting. I also do very minor gunsmithing.

    My primary objective in all things is safety first.

Posted 01 November 2019 - 12:15 AM

Thanks for the weights Bob.

From the small data set thus far, looks like 1 pound 12 oz may be the Sweet Spot, + or - 1/2 an ounce

PK, anyone who has frequented these forms knows you are one of the main experts here, especially related to West Hurley issues. Could you enlighten the rest of us with what the potential problem(s) with a West Hurley bolt would be? And why I would not want to run it in my original savage M1?

Edited by imageaudio, 01 November 2019 - 12:49 AM.

  • 0

#8 PK.

PK.

    Technical Expert

  • Board Benefactor
  • 1578 posts
  • Gender:Male
  • Location:CO, USA
  • Interests:Full time gunsmith who loves Thompson's, 43+ years experience.

Posted 01 November 2019 - 09:05 AM

To many to mention, i don't have time to write a paper on it, as interesting as that might be. 


  • 0

#9 TSMGguy

TSMGguy

    Respected Member

  • Board Benefactor
  • 2547 posts
  • Gender:Male
  • Location:West of the Pecos, Texas
  • Interests:Motorcycles, old airplanes, and guns.

Posted 01 November 2019 - 09:38 AM

Thanks, TD:

 

https://www.smallarm...?idarticles=224

 

The WH bolts can be badly out of spec. Measure the length of one vs. original GI. The WH bolt is too long.

 

PK rebuilt my WH M1. Today it's beautiful, and almost all GI except for the receiver and frame. At first I retained the WH parts just as curiosities. Later I put them on a concrete slab and pounded them to scrap with a 10 lb. sledge hammer. There's no way they'll end up on someone's gun.

 

Parked original M1A1 bolts have been refinished. All were blued when produced.

Attached Files


Edited by TSMGguy, 01 November 2019 - 11:25 AM.

  • 0

#10 Adg105200

Adg105200

    RKI Member

  • Board Donor
  • 847 posts
  • Gender:Male
  • Location:Eastern USA
  • Interests:Ww2, Thompsons & many other guns, hunting, fishing, tools, woodworking

Posted 06 November 2019 - 08:22 AM

Just got around to weighing my "nickel" M1 bolt and it came in at 1lb 12.2oz on my postal scale.

Andrew
  • 0