1928 west hurley 22's observations

[deerslayer]

I have seen 4 different varieties of bolt used in the 1928 west hurley 22 machine guns.

 

1.  An actual hammer and moving firing pin basically like a .45 acp thompson.

2.  Fixed firing pin (machined or possibly welded steel) on the bottom of the bolt

3.  Fixed firing pin on the top of the bolt face that is pinned in place

4.  Flush fit, no actual firing pin.  The bolt crushes the whole case rim which pops the primer.

 

3 and 4 never work well in my experience, and are the ones that I have modified the most to function.  I follow the pattern of number 2.

Number 3 with the firing pin on the top of the bolt face has problems as the round gets caught sliding up into place as it chambers.

The gun can take the 30 ceiner mags with adaptor, the pps50 modufied drums, and the 22 insert 45 acp magazines.  

They will not work with the blackdog magazines.

 

Also the magazines for the 1927A3 are the same except the fit is 1/10 height difference.  (This can be adjusted if needed).

 

Bad fitting extractors are common.  Also rough chambers can be encountered also.  I had one gun here that the inner steel barrel liner had slipped forward thus the headspace was long and you didnt get a primer pop.

[dalbert]

Thanks, Dan, for this information.  We are lucky to have you documenting this, which should prove helpful to someone in the future.  Your observations will help us better understand why the .22 WH Thompsons have varied reputation for reliability.

David

[deerslayer]

I received a handwritten communication that a 5th variation occurs.    A small piece of metal is fixed into the barrel right at the chamber rim to cause a primer hit on the front/top edge of the rim when pushed home by a flat faced bolt.  So a number 4 (flat faced bolt) but an enhanced chamber.  The idea is intriguing enough to perhaps try building an open bolt full auto that functions that way.  

Edited November 10, 2025 by deerslayer

[anjong-ni]

 

The author claims that this is a "full-auto made from a semi".

Interesting design.

Which one of the "bolt-possibilities" it this?   Phil

 

https://www.gunbroker.com/item/1134809945

Edited November 10, 2025 by anjong-ni

[deerslayer]

Number 4 remade into number 2, i did the work on it.

Edited November 11, 2025 by deerslayer

[68coupe]

4 hours ago, deerslayer said:

Number 4 remade into number 2, i did the work on it.

Laughs hysterically....

[Doug Quaid]

On 11/9/2025 at 8:40 AM, dalbert said:

Thanks, Dan, for this information.  We are lucky to have you documenting this, which should prove helpful to someone in the future.  Your observations will help us better understand why the .22 WH Thompsons have varied reputation for reliability.

David

This website is a fantastic source of information.

I actually do not know that much about Thompsons.  I'm continuously amazed at how much information the members here know and share.

Also, you guys are very sober-minded about digging up new facts, as opposed to pushing favorite opinions.  It's not common to find a large group of collectors that have that skeptical, careful, information-seeking attitude. 

A lot of people out there resist new information if it contradicts their existing knowledge.  Almost like it is an affront to their expertise.  I rarely see that attitude here.

Well, done guys.  You are the gold standard.

 

[deerslayer]

I just happened to have a customer send me a gun with the pivoting hammer and moving firing pin.  Thought id add it to the database here!  This of course is reminiscent of how the actual 45 caliber Gun Works. One warning on testing this gun with Winchester Wildcat just the impact of the bolt will detonate the round without the firing pin actually hitting the rim. I have found Wildcat ammo is very primer sensitive and this proves it.

[TD.]

Dan,

I believe this is variation #1, above. Can you describe the problem with this WH, and how you are going to correct it? I was thinking this early variation worked best. 

Thanks for all you do.

[deerslayer]

So the potential problem with the moving firing pin is that the design of the bolt is different than a 45 caliber. When the bolt is slamming all the way forward the firing pin is also moving forward Beyond the Edge of the bolt face. In both guns. In a 45 caliber the round doesn't seat fully against the face of the bolt until the bolt goes closed. At which point the primer is hit by the firing pin. In the 22 the case is sliding up against the face of the bolt as it Chambers. Therefore if the firing pin is protruding a little bit right before the bolt fully slams home the rim can catch on the edge of the firing pin at the top of the bolt on the 22. This can lead to failures to fire.

 

 

[deerslayer]

This particular gun came in so I could build an extra magazine for it and troubleshoot why it didn't work very well. Existing magazines were not fitted well. And as mentioned above it would have failures to fire due to the firing pin design. I have changed it to number three.

[68coupe]

On 11/11/2025 at 9:17 PM, 68coupe said:

Laughs hysterically....

That doesn't read like I intended it to. My apologies. I WAS laughing, but because you made a poor design function, NOT because I think poorly of your work. Quite the contrary.

V/R, Karl, 68coupe

[deerslayer]

No worries!