1928 Thompson - The Firearms Forum

toppkatt · 10-17-2011, 11:51 AM

Got to shoot a Thompson model 1928 this past weekend. Was fun, BUT do all of them have like 8 or 10 pound triggers? Sheesh, no wonder they are full auto. Can't hit the broadside of a barn with a trigger like that

Shooter45 · 10-18-2011, 02:22 PM

The trigger is not one of the finer points of the Thompson.

muddober · 10-18-2011, 11:18 PM

The trigger on a 28 is easy to fix but you don't necessarily want a 4 pound trigger pull on any full auto gun, much less a Thompson with that huge heavy bolt that fires from an open position. As a point of interest the model 28 and the model 21 T gun uses what is called a Blish system which is two pieces of brass that fit together in such a way that as the gun fires these two pieces create a wedge that binds or drags inside the receiver causing a delayed blow back as opposed to gun just running off with itself. The only other gun that I am aware that uses a modified version of that system is the all hand made Cosmi shotgun. The later T guns of the Koren war did not use that system but rather a fixed firing pin monolithic to a heavier bolt. Additionally those later guns will not take the drum magazines. A T gun in the hands of someone who knows the gun is an awesome weapon, but as a battle gun they are the worst. The open bolt and temperature variances issues make them in my view a poor choice for a battle gun and the 45 Auto round will not shoot nearly as far as a 22 long rifle.

Ron

zant · 10-20-2011, 07:55 PM

About the "Blish Lock"-totally unneeded-does nothing in reality...same as the "cooling jacket" on a Lewis MG....Friend has a 1943 M1A1 Thompson with a 6lb trigger-what a great shooter..

Jim K · 10-26-2011, 11:16 AM

Well, not so fast. The Blish lock really does work, though not to the extent originally claimed. First, it is not "two pieces of brass", it is one "H" shaped piece of bronze. When Savage was trying to eliminate it, they found that they had to beef up the rear of the receiver because in the absence of the Blish lock, the bolt recoil momentum was considerably increased and the bolt broke out the rear of the receiver.

Another common Thompson myth is that troops took the Blish lock out of the guns and threw them away. Not true. While the 1921/28 can be modified to eliminate the lock (commonly called the "H block") just throwing it away won't work, as it is the connection between the actuator (the part with the knob) and the bolt.

The Lewis gun cooling jacket also works. The jacket itself does not cool anything, but the way it is designed, the muzzle blast pulls air through the jacket, cooling the barrel. The aircraft guns didn't need the jacket because the motion of the plane through the air provided enough cooling.

As to the .45 ACP, it might not shoot as far as a .22, but subguns are not intended for long range shooting at Camp Perry. And I know the .45 will hit a lot harder than a .22.

Regarding a trigger "fix", though, Muddober is right; with that heavy bolt coming forward, it takes a good solid sear and good engagement to stop it, so any tinkering could easily result in a gun that won't quit, a bad situation.

Jim

Josh Smith · 10-26-2011, 04:49 PM

Hello,

I do believe the Blish lock was done away with on the 1928 (or maybe 1928a1?). I know it didn't exist on the M1 Tommy.

Performance didn't suffer so far as I've been able to discern.

Regards,

Josh

toppkatt · 10-29-2011, 09:00 AM

Thanks for the info Jim K. I had heard of the Blish locking system on the Thompson but never really looked into it any deeper. Sound like you did.
Appreciate it!

deadin · 10-29-2011, 01:14 PM

I seem to remember that Thompson tried the Blish idea on a 30/06 that was submitted for the trials where the Garand was accepted. As it was basically almost a blowback, I understand that the ejection was quite vigorous. (To the point of sticking empties in a oak door beside the firing line....

)

Alpo · 10-29-2011, 02:08 PM

Kinda sorta. Thompson tried the Blish lock on a 30 caliber rifle, that's true. But it was in 1917 or 18, long before the Garand tests. He found that the government 30 caliber cartridge was too strong for the lock, and the best compromise between power and reliability, that was already in the government arsenal, was the 45 ACP. So the Thompson Automatic Rifle morphed into the Thompson Sub Machine Gun.

BETH · 10-29-2011, 03:21 PM

can i seea picture please

Alpo · 10-29-2011, 05:42 PM

Blish lock, bolt apart

Blish lock, bolt together

Blish lock by itself, taken off the bolt.

Good article explaining the theory. You want about 1/4 of the way down the page. Sunday, August 22. The Blish Lock.
http://firearmshistory.blogspot.com/...1_archive.html

Alpo · 10-29-2011, 05:44 PM

As you can see, the bronze piece holds the two pieces of the bolt together, and (as Jim said) if you were to "take the lock out and toss it", the gun could not work.

Alpo · 10-29-2011, 05:46 PM

If you were asking for a picture of the Thompson rifle - I don't think any exist.

Although I do have a picture of an experimental machinegun.

deadin · 10-29-2011, 11:52 PM

Well, you made me go dig in my library. You're right, but so am I. The Thompson Blish lock .30 cal rifle was submited for trial in 1920 (or so) at the same time as Garand submitted a primer actuated design. Neither worked out but Garands was promising enough that he was retained by the government for further designs, one resulting in the M1.

FWIW there is a picture of the Thompson rifle in W.H.B. Smith's "Small Arms of the World". It is on page 85 of the 10th Edition.

10-17-2011, 11:51 AM	#1
toppkatt Member Join Date: Jul 2011 Posts: 34	1928 Thompson Got to shoot a Thompson model 1928 this past weekend. Was fun, BUT do all of them have like 8 or 10 pound triggers? Sheesh, no wonder they are full auto. Can't hit the broadside of a barn with a trigger like that -->

10-18-2011, 02:22 PM	#2
Shooter45 Administrator Join Date: Feb 2001 Contributor Posts: 8,755	Re: 1928 Thompson The trigger is not one of the finer points of the Thompson.

10-18-2011, 11:18 PM	#3
muddober Advanced Senior Member Join Date: Sep 2008 Posts: 1,436	Re: 1928 Thompson The trigger on a 28 is easy to fix but you don't necessarily want a 4 pound trigger pull on any full auto gun, much less a Thompson with that huge heavy bolt that fires from an open position. As a point of interest the model 28 and the model 21 T gun uses what is called a Blish system which is two pieces of brass that fit together in such a way that as the gun fires these two pieces create a wedge that binds or drags inside the receiver causing a delayed blow back as opposed to gun just running off with itself. The only other gun that I am aware that uses a modified version of that system is the all hand made Cosmi shotgun. The later T guns of the Koren war did not use that system but rather a fixed firing pin monolithic to a heavier bolt. Additionally those later guns will not take the drum magazines. A T gun in the hands of someone who knows the gun is an awesome weapon, but as a battle gun they are the worst. The open bolt and temperature variances issues make them in my view a poor choice for a battle gun and the 45 Auto round will not shoot nearly as far as a 22 long rifle. Ron

10-20-2011, 07:55 PM	#4
zant V.I.P. Member Join Date: Sep 2009 Location: S.Al Posts: 249	Re: 1928 Thompson About the "Blish Lock"-totally unneeded-does nothing in reality...same as the "cooling jacket" on a Lewis MG....Friend has a 1943 M1A1 Thompson with a 6lb trigger-what a great shooter..

10-26-2011, 11:16 AM	#5
Jim K Advanced Senior Member Join Date: Dec 2009 Posts: 6,408	Re: 1928 Thompson Well, not so fast. The Blish lock really does work, though not to the extent originally claimed. First, it is not "two pieces of brass", it is one "H" shaped piece of bronze. When Savage was trying to eliminate it, they found that they had to beef up the rear of the receiver because in the absence of the Blish lock, the bolt recoil momentum was considerably increased and the bolt broke out the rear of the receiver. Another common Thompson myth is that troops took the Blish lock out of the guns and threw them away. Not true. While the 1921/28 can be modified to eliminate the lock (commonly called the "H block") just throwing it away won't work, as it is the connection between the actuator (the part with the knob) and the bolt. The Lewis gun cooling jacket also works. The jacket itself does not cool anything, but the way it is designed, the muzzle blast pulls air through the jacket, cooling the barrel. The aircraft guns didn't need the jacket because the motion of the plane through the air provided enough cooling. As to the .45 ACP, it might not shoot as far as a .22, but subguns are not intended for long range shooting at Camp Perry. And I know the .45 will hit a lot harder than a .22. Regarding a trigger "fix", though, Muddober is right; with that heavy bolt coming forward, it takes a good solid sear and good engagement to stop it, so any tinkering could easily result in a gun that won't quit, a bad situation. Jim

10-26-2011, 04:49 PM	#6
Josh Smith V.I.P. Member Join Date: Nov 2009 Location: Wabash IN Contributor Posts: 66	Re: 1928 Thompson Hello, I do believe the Blish lock was done away with on the 1928 (or maybe 1928a1?). I know it didn't exist on the M1 Tommy. Performance didn't suffer so far as I've been able to discern. Regards, Josh

10-29-2011, 09:00 AM	#7
toppkatt Member Join Date: Jul 2011 Posts: 34	Re: 1928 Thompson Thanks for the info Jim K. I had heard of the Blish locking system on the Thompson but never really looked into it any deeper. Sound like you did. Appreciate it!

10-29-2011, 01:14 PM	#8
deadin Senior Member Join Date: May 2006 Posts: 858	Re: 1928 Thompson I seem to remember that Thompson tried the Blish idea on a 30/06 that was submitted for the trials where the Garand was accepted. As it was basically almost a blowback, I understand that the ejection was quite vigorous. (To the point of sticking empties in a oak door beside the firing line....)

10-29-2011, 02:08 PM	#9
Alpo Advanced Senior Member Join Date: Feb 2007 Location: NW Florida Posts: 8,662	Re: 1928 Thompson Kinda sorta. Thompson tried the Blish lock on a 30 caliber rifle, that's true. But it was in 1917 or 18, long before the Garand tests. He found that the government 30 caliber cartridge was too strong for the lock, and the best compromise between power and reliability, that was already in the government arsenal, was the 45 ACP. So the Thompson Automatic Rifle morphed into the Thompson Sub Machine Gun. __________________ Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297 I always take precautions. Beware the Evil Bullet Fairies.

10-29-2011, 03:21 PM	#10
BETH Advanced Senior Member Join Date: Jul 2009 Location: naugatuck,Ct. Contributor Posts: 6,676	Re: 1928 Thompson can i seea picture please

10-29-2011, 05:42 PM	#11
Alpo Advanced Senior Member Join Date: Feb 2007 Location: NW Florida Posts: 8,662	Re: 1928 Thompson Blish lock, bolt apart Blish lock, bolt together Blish lock by itself, taken off the bolt. Good article explaining the theory. You want about 1/4 of the way down the page. Sunday, August 22. The Blish Lock. http://firearmshistory.blogspot.com/...1_archive.html __________________ Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297 I always take precautions. Beware the Evil Bullet Fairies.

10-29-2011, 05:44 PM	#12
Alpo Advanced Senior Member Join Date: Feb 2007 Location: NW Florida Posts: 8,662	Re: 1928 Thompson As you can see, the bronze piece holds the two pieces of the bolt together, and (as Jim said) if you were to "take the lock out and toss it", the gun could not work. __________________ Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297 I always take precautions. Beware the Evil Bullet Fairies.

10-29-2011, 05:46 PM	#13
Alpo Advanced Senior Member Join Date: Feb 2007 Location: NW Florida Posts: 8,662	Re: 1928 Thompson If you were asking for a picture of the Thompson rifle - I don't think any exist. Although I do have a picture of an experimental machinegun. Attached Images __________________ Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297 I always take precautions. Beware the Evil Bullet Fairies. Last edited by Alpo; 10-30-2011 at 09:44 AM..

10-29-2011, 11:52 PM	#14
deadin Senior Member Join Date: May 2006 Posts: 858	Well, you made me go dig in my library. You're right, but so am I. The Thompson Blish lock .30 cal rifle was submited for trial in 1920 (or so) at the same time as Garand submitted a primer actuated design. Neither worked out but Garands was promising enough that he was retained by the government for further designs, one resulting in the M1. FWIW there is a picture of the Thompson rifle in W.H.B. Smith's "Small Arms of the World". It is on page 85 of the 10th Edition. Last edited by deadin; 10-29-2011 at 11:54 PM..