Jump to content


Photo
* * - - - 1 votes

M1A1 blows gas out the back end into my face


  • Please log in to reply
17 replies to this topic

#1 Grease Gunner

Grease Gunner

    RKI Member

  • Board Benefactor
  • 220 posts
  • Gender:Male

Posted 09 April 2019 - 09:42 PM

Its so wierd, I have shot at least 10 thompsons, 1928s and m1a1s and only this one does that,

Its like someone blowing air into your face, not a lot but enough to make me squint as I shoot

I am going to look at the buffer. Any board members have an answer? 

Its not obvious to me

Thanks

 


  • 0

#2 BillyDixon

BillyDixon

    Regular Member

  • Regular Group
  • 155 posts

Posted 09 April 2019 - 10:18 PM

are you shooting some kind of reloads?? what powder you useing??


  • 0

#3 john

john

    Long Time RKI Member

  • Regular Group
  • 677 posts
  • Gender:Male
  • Location:Saint Paul, Minnesota

Posted 09 April 2019 - 11:06 PM

Both my '28s do that too....but I run them wet so get a mouthful of CLP fir the first couple mags after I oil them up.
Just that all the parts are snug and well-machined....add oil and they're going to seal and act like a piston compressor.
  • 0

#4 Grasshopper

Grasshopper

    Long Time RKI Member

  • Board Donor
  • 261 posts
  • Gender:Male
  • Location:Sunny Florida
  • Interests:Engines, Tractors(old, rusty is better), mechanisms, and the occasional MG

Posted 09 April 2019 - 11:54 PM

Hi, 

 

My M1's do that all the time.  More than the top-cockers.  The top-cockers have the groove in the sides of the receiver.  I leave the felt at home.  That allows the 21s or 28s to breath down the sides.  The M1/M1A doesn't have the extra vent slots.  When I oil them up I get quite a squirt of air out the back.

 

Nature of the beasts in my experience.

 

YMMV,

 

Grasshopper


  • 0

#5 jim c 351

jim c 351

    Long Time RKI Member

  • Board Benefactor
  • 2966 posts
  • Gender:Male
  • Location:Ohio

Posted 10 April 2019 - 07:01 AM

I hope you are wearing good shooting glasses. Should eliminate the need to squint. Also the need to go blind.

I notice it more with the 28. After shooting a few mags I have to clean the oil from my glasses.

Jim C


  • 0

#6 TSMGguy

TSMGguy

    Respected Member

  • Board Benefactor
  • 2439 posts
  • Gender:Male
  • Location:West of the Pecos, Texas
  • Interests:Motorcycles, old airplanes, and guns.

Posted 10 April 2019 - 09:38 AM

You're shooting left handed, huh? So do I. After my M1 has blown the last of the excess lube and CLP into my face, I hardly notice the blow-back. Shooting glasses a must.


  • 0

#7 Grease Gunner

Grease Gunner

    RKI Member

  • Board Benefactor
  • 220 posts
  • Gender:Male

Posted 10 April 2019 - 09:48 AM

Thanks for all the input.

The top cockers dont do that for me

Yes, I am wearing shooting glasses

shooting right handed 

And only factory ammo


Edited by Grease Gunner, 10 April 2019 - 09:49 AM.

  • 0

#8 Merry Ploughboy

Merry Ploughboy

    Long Time RKI Member

  • Regular Group
  • 1056 posts
  • Gender:Male

Posted 10 April 2019 - 10:45 AM

As the oil blow back is inherent to the Thompson, this may not be permissible for competition shooting in "original configuration" class shoots. On Model 1921 and 1928 sized pilots (I don't know if the M1/M1A1 pilot is the same diameter) a no. 36 o-ring stretched over the pilot protrusion out of the receiver and slid snug against the back of the receiver is pretty effective at turning much of the spray into a dribble.  The dribble can occasionally be wiped off the receiver and frame.

 

I did come up with a shield that adds even more protection from the oil, but I believe the o-ring alone is sufficiently effective for most shooting.

 

Enjoy your Thompsons, and shoot safe.

 

MHO, YMMV, etc.


  • 0

#9 DZelenka

DZelenka

    RKI Member

  • Regular Group
  • 668 posts
  • Gender:Male

Posted 10 April 2019 - 10:51 AM

As the oil blow back is inherent to the Thompson, this may not be permissible for competition shooting in "original configuration" class shoots. On Model 1921 and 1928 sized pilots (I don't know if the M1/M1A1 pilot is the same diameter) a no. 36 o-ring stretched over the pilot protrusion out of the receiver and slid snug against the back of the receiver is pretty effective at turning much of the spray into a dribble.  The dribble can occasionally be wiped off the receiver and frame.

 

I did come up with a shield that adds even more protection from the oil, but I believe the o-ring alone is sufficiently effective for most shooting.

 

Enjoy your Thompsons, and shoot safe.

 

MHO, YMMV, etc.

Have you tried to put the O ring inside the receiver?


  • 0

#10 Merry Ploughboy

Merry Ploughboy

    Long Time RKI Member

  • Regular Group
  • 1056 posts
  • Gender:Male

Posted 10 April 2019 - 03:50 PM

IIRC, I did look and it appeared that the o-ring would likely get chewed up if put inside because it would probably have to be placed between the buffer and the receiver wall to be effective.  Perhaps I made too many or incorrect assumptions.  One could try, though I don't plan on doing so.


  • 0

#11 john

john

    Long Time RKI Member

  • Regular Group
  • 677 posts
  • Gender:Male
  • Location:Saint Paul, Minnesota

Posted 10 April 2019 - 08:06 PM

An o-ring ...What a great idea - that is, if ya don't like the taste of Breakfree in the morning!
I say that because most folks shooting Thompson's always wear the same grin!
  • 0

#12 1921A

1921A

    Respected Member

  • Board Benefactor
  • 593 posts
  • Gender:Male

Posted 11 April 2019 - 06:46 PM

I think you guys might be putting to much oil in your guns. We shoot 21s, 28s and M1s on a fairly regular basis and the only time I see this happen is when somebody gets a little over zealous with the oil. When I clean my guns I put a very small dab of lubricant on each face of the bolt and wipe it with my finger to spread a thin film where the bolt slides against the trigger frame and receiver. 21/21 actions also get a drop of oil on each pad after cleaning.

My trigger frame components are usually left dry. You can use a cloth with a very small amount of oil to wipe lubricant on trigger frame components when you disassemble for cleaning. Excess oil here just creates gunk from powder residue and carbon.
  • 0

#13 ppgcowboy

ppgcowboy

    RKI Member

  • Board Donor
  • 883 posts
  • Gender:Male
  • Location:South West Montana
  • Interests:Guns, aviation, didgeridoo, banjo, metal detecting.

Posted 11 April 2019 - 07:55 PM

They say shoot am wet.
  • 0

#14 NFA amnesty

NFA amnesty

    Regular Member

  • Regular Group
  • 142 posts
  • Gender:Male
  • Location:Oregon

Posted 11 April 2019 - 08:48 PM

Can you use gun grease on the bolt or do you guys recommend oil?  I someday will receive my M1A1 when the ATF NFA Branch decides I am worthy enough to have my stamp.  Of course at almost 10 months and not assigned to an examiner yet, could be in for a very long wait. 


Edited by NFA amnesty, 11 April 2019 - 08:49 PM.

  • 0

#15 StrangeRanger

StrangeRanger

    Regular Member

  • Regular Group
  • 220 posts
  • Gender:Male
  • Location:Ohio

Posted 11 April 2019 - 09:11 PM

On my M1 I grease the recoil spring and add oil, smear a little grease on the top, bottom and sides of the bolt and add oil, oil the hammer and firing pin.  Lately I've been using CLP.  Yes, I wear shooting glasses and yes, they get wet.


  • 0

#16 NFA amnesty

NFA amnesty

    Regular Member

  • Regular Group
  • 142 posts
  • Gender:Male
  • Location:Oregon

Posted 13 April 2019 - 03:03 PM

On my M1 I grease the recoil spring and add oil, smear a little grease on the top, bottom and sides of the bolt and add oil, oil the hammer and firing pin.  Lately I've been using CLP.  Yes, I wear shooting glasses and yes, they get wet.

Thanks SR.


  • 0

#17 reconbob

reconbob

    Technical Expert

  • Board Benefactor
  • 2482 posts
  • Gender:Male

Posted 14 April 2019 - 07:52 PM

    For what its worth, do not use grease on/in the trigger frame. The disconnextor (the little lever

that fits in the trigger) spring is a very weak spring since all it is designed to do is flip the disconnector

out from under the sear lever. It is not strong enough to overcome grease. We recently had a gun

in here that "didn't work" and the owner had loaded the trigger frame with thick white moly grease

which completely clogged the disconnector. All we had to do was degrease it and it worked fine.

 

Bob


  • 0

#18 NFA amnesty

NFA amnesty

    Regular Member

  • Regular Group
  • 142 posts
  • Gender:Male
  • Location:Oregon

Posted 14 April 2019 - 09:56 PM

    For what its worth, do not use grease on/in the trigger frame. The disconnextor (the little lever

that fits in the trigger) spring is a very weak spring since all it is designed to do is flip the disconnector

out from under the sear lever. It is not strong enough to overcome grease. We recently had a gun

in here that "didn't work" and the owner had loaded the trigger frame with thick white moly grease

which completely clogged the disconnector. All we had to do was degrease it and it worked fine.

 

Bob

Great info on what not to do.  Thanks Bob.


  • 0