M1 buffer system in a 1928

[Paladin601]

Been looking at drawing and cut up recievers for the 1928 Thompson. It got me to thinking as to why a buffer system that is on the M1 Thompson, could not be used on the'28. The pilot rod would be turned down to avoid modifying the receiver with a larger hole. Then The spring would be installed through the hole reducing the chance of kinking the spring, the buffer would be dropped right over the rod.

 

Maybe, the hole would have to be enlarged just enough to allow the spring to be inserted, hhhmmm.

[bob241]

Acording to information on Doug Richardson webb Sight, the pilot hole in a M1 or M1Al receiver is in a different position than a 1928Al receiver. it is either higher or lower, I do not remember which.

[DLansky]

a number of west hurley 28 thompsons featured an M1 pilot rod to which a small disc was tack welded. they were known to fail during fire and exit the rear of the receiver into your shoulder or chest. this is one of the reasons you see warnings to always replace west hurley parts with military parts.

[Paladin601]

the pilot slot would have to change, it is lower. But can be done, don't know if that would weaken the buffer though

[mnshooter]

One reason not to do this: The GI M1 buffer is worthless as a buffer. It has zero compressibility with the bolt forces involved, and instead transmits the shock directly to the rear of the receiver via the rigid rivets. The fact that the M1 pattern has held up so well is a tribute to the strength of the gun, not at all to the effect of the buffer.

 

Now, using the Richardson neoprene M1 buffer system or concept, maybe something could be worked out for the 28 that would install from the bottom. But, the one piece GI pilot is about as fool proof as it gets, and you'll never have to worry about it becoming part of your shoulder.

[Paladin601]

Right as rain, Should of thought that Richardson had already thought of that. This is exactly what I wanted to do. Thanks

 

 

 

http://www.thompsonsmg.com/2M2%20SPECIAL%20PARTS%20hppscan94.jpg

Edited July 5, 2015 by Paladin601

[buzz]

this sounds like a good idea

 

mnshooter -

 

what makes you say that the m1 buffer is harder than the 28 buffer?

 

the 28 buffer appears to be a phenolic resin washer, which is very hard stuff, about 55 times as hard as rubber

 

phenolic resin was around in 1921, they called it bakelite

 

did they use something different in the M1 buffer?

Edited July 5, 2015 by buzz

[Paladin601]

I was thinking originally a double spring, like the H&K USP, where all slid in through the pilot hole, but thought I was taking something simple and complicating it. I think the M1 type would be the most durable

[mnshooter]

mnshooter -

 

what makes you say that the m1 buffer is harder than the 28 buffer?

 

 

 

did they use something different in the M1 buffer?

 

I believe the material is the same in both GI buffers.

The difference isn't in the phenol material (which, as mentioned earlier can crumble to pieces and allow the parts to impact unimpeded), but is in the way the M1 buffer is constructed, with two rivets holding the assembly together.

The rivets act as rigid posts, bypassing the phenolic material and transmitting any force directly through.

My own tests involved an arbor press and gauge, compressing and measuring the additional movement of the ram after it was pushing rather hard against the M1 buffer.

Until it created enough pressure to crush the buffer a very slight but measurable amount, which meant actually crushing the rivets, -there was no measurable deflection.

In comparison, testing the hardest neoprene buffer was like squeezing a marshmallow.

This was just an improvised test, but left no doubt in my mind regarding the differences in buffering effect.

Edited July 5, 2015 by mnshooter

[buzz]

Interesting

Edited July 5, 2015 by buzz

[Paladin601]

I think we now have the technology to make a buffer without rivets, we could make it with liquid urethane

[darrylta]

D. Richardson at one time offered a two piece bonded neoprene / metal M1 style buffer. I have them in both of my M1's, they work great.

It would be great if someone would advance his design and start production.

 

PK's 21 style buffer system for the 1928's is hands down the best buffer system. It has a modern 28 style buffer disc and a 1921

style buffer tube that allows the use of the 1921 recoil spring. I have them in my 28 Hurley and both NAC-Colts.

 

Darryl

Edited July 5, 2015 by darrylta

[m60mgman]

I just got in one of PK's hybrid buffer pilots. Nicely made. Now I just need the buffers...

[Paladin601]

starting to sound like I am trying to reinvent the wheel.