Blank Adapring 1928

[beltfed 30]

ive already made a fake cutts to thd in 12x20 allen plugs do i need to use an m1 bolt so it runs or can i leave 28 bolt assm. in and also any recomendations on orifice sizes thanks bob b

[TheGunny]

ive already made a fake cutts to thd in 12x20 allen plugs do i need to use an m1 bolt so it runs or can i leave 28 bolt assm. in and also any recomendations on orifice sizes thanks bob b

 

The only 1928 I've seen that was blank adapted, the guy had a spare Blish Lock, with the lugs ground off and he was using a 3/16 orifice with Swanson Blanks. As far as the orifice, always start big and work your way down until the gun runs like you want. Get it to work reliably in semi auto, then test your orifice size on FA.

 

I have a M1, so I can't swear by the blish lock lug mods.......! The one I have seen seemed to work pretty well!

 

[Tman]

Bob,

I have a WH 28 that is blank adapted. I had Paul (PK) set me up with a quick change system so I can swap out the barrel to go from blanks to live. I will have to break out the measuring tools to see what orifice size I use. When I shoot blanks, I use a Blish lock that has the ears removed in a '28 bolt. Search the site for pics of my gun with the barrel change system. You may want to go that route.

[Jay Baker]

Why do you use a Blish lock that has its ears removed? I ask because my '28 is blank adapted but I use the stock lock and Swanson blanks. I haven't had any issues that I recognize but I am curious.

[PhilOhio]

Jay,

 

What you say is even more interesting, using the stock lock. Of course, the Swanson blanks are considered to be rather powerful, I believe. What is the exact diameter of your restrictor?

[rjb1]

Before this topic gets too outdated, I wanted to add that I blank-adapted my 1928 and it worked fine with the Blish lock still there and unmodified. I used it at two WWII reenactments and fired about 200 rounds with no problems.

 

I used blanks made by a local individual who used them in both M1 and 1928 guns. They don't seem as hot as Swanson's. (subjective opinion)

 

Joel

 

(The "orifice size" is not a relevant bit of information since I used a special "no-drill, no-tap" blank adapter that I designed and built myself.)

[Jay Baker]

Well Phil, I don't know what size the aperture is. I'll have to ask the fellow who installed it. He's a well experienced reenactor and has blanked a wide variety of weapons.

[Sarge]

Hell, why not just remove the blish lock completely? I've heard that the Brits did so with many of their Thompsons.

I had a friend many years ago who blank adapted a 21 Thompson. As far as I know all he did was install a BFA.

I have 2 M1A1s and the hole size is different for each one because of the difference in recopil springs. The holes are drilled with #19 & 22 drill bits.

I Do NOT reccomend swansons blanks as they are loaded hot as hell and at least some have flash powder to give a good muzzle flash for the movies.

I reccomend Richard Satterfield - Blanksguy2001@chartermi.net. I've used his blanks for many years.

Sarge

[PhilOhio]

Sarge,

 

Why not just remove the Blish lock completely? You can't, because something has to connect the bolt and the actuator in a '28. A Blish without ears does that. I have a couple, made from steel, which I call "Blish unlockers".

 

But if you are using blanks so hot that they overcome the restraining functions of an operable Blish lock, that is hot enough to send the bolt back very smartly...against the buffer and the rear of the receiver. The rear of a '28 receiver does not have the same strength to resist this battering, as does the Blish-less M1 and M1A1 models. With even hot blanks, this may or may not be a problem. But it's a factor to keep in mind. This prompted me to ask the initial question of Jay.

 

Regarding the hot theatrical blanks which are used to get all that great white flash we see in the movies, it is the characteristic color of burning aluminum or magnesium powder. It is great for movie making and very bad for guns. The heat of combustion is dramatically higher and more destructive than smokeless powder of any kind.

 

Remember, this type of powder is the main heat raising component of the military thermite grenades used to weld the actions of enemy artillery pieces into uselessness during wartime. Of course, the proportions and oxidizers are a little different, but the temperatures are somewhat similar.

 

This is part of the reason why people don't use their good barrels for firing blanks. The other part is damage caused to the throat, the rifling lead, when a typical star crimp opens under high pressure and with sharp shock.

 

A couple years ago, I got all set up to begin shooting blanks. I put the project on hold, as I began to develop an appreciation for some of the downside factors involved. I may still do it, if and when I get an expendable barrel. But then there would be the temptation to use even that for another caliber conversion, with liner.

 

Joel,

 

Diameter of the hole in the muzzle restrictor is ALWAYS a critical factor with blanks. It must be tailored to the blanks used, as there seems to be a lot of variation among the commercial ones, as some of you note. That little hole determines the pressure available to operate the action, and the energy with which the bolt moves to the rear...just enough, or with too much battering power left at the end.

 

It seems to me that there are more opportunities to make damaging mistakes when setting up to shoot blanks, than when selecting published live round loads for the Thompson. The gun is very rugged, but blanks are quite a different animal. It takes a little thought and preparation, and I have not worked my way completely through it, to decide if the input is worth the result. For reenactors, certainly it is.

[rjb1]

Phil,

 

You are 100% correct.

 

I certainly concur that the pressure bleedoff opening *area* is crucial when blank adapting, and that typically that area is expressed indirectly by specifying the orifice size (diameter). However, the reason that I didn't include any specifics concerning orifice size, and said that they wouldn't be relevant in this case, is that in this special gadget that I designed/built there is more than one hole and they are not all the same size.

 

It would be too prone to misinterpretation to just throw the numbers out there. It was too finicky to build and test this gadget to take a chance on someone misinterpreting the numbers and messing up a good Thompson.

 

Which leads me to concur with you again and agree that it's easier to shoot officially-published "real" loads than to try to get any firearm (Thompson or other) to reliably operate with blanks.

 

It's sufficiently nerve-wracking that after only two reenactments I took the 1928 out of service (even though it was working fine) and went ahead and did a convention blank-adapting job on the WH M1A1.

 

Joel

[Jay Baker]

Well, you guys have raised some good points. On Swanson blanks, I was unaware of the flash component and since we don't reenact night fire fights for safety reasons, I will make my next blank purchase elsewhere. Of course, I used an old WH barrel for my 28's blanking so as to not ruin a good WW2 vintage barrel. Moreover, I'm very conservative when shooting blanks during a reenactment because I pay for everything. I've never broken the 200 round mark in a single weekend event. There's no use blasting away just to make noise if the other side won't take a hit unless its delivered point blank(no pun intended.)

[PhilOhio]

I don't want to have the effect of warning anybody away from Swanson blanks, which I have never personally used. By all accounts they are excellent. We just need to understand that there are some special considerations in using any of these high powered flash bangers with the aluminum or magnesxium powder mixed in. You have to consider some of your hadware components to be at least a little bit "sacrificial", and plan accordingly.

[Reenactor]

I've used Swanson blanks 3 to 6 times a year for 18 years on two rebarrelled 1921s. I tried to shoot 200 blanks in one show once, and jamming because the gun got dirty was my problem. It went semi-auto at about 190 rounds.

 

I remember once asking Joe at someone's urging, if he included flash powder or some other magic ingredient in his blanks. His answer was No. His blanks are excellent. I scrub and oil everything well between each show, and probably have to replace one blank restrictor--the hole does get burned out to a bigger size over time--about each 18 months. I also don't shoot over 150 shots before cleaning any more, no matter how many gangsters/coppers are still standing as potential targets.

[PhilOhio]

I've used Swanson blanks 3 to 6 times a year for 18 years on two rebarrelled 1921s. I tried to shoot 200 blanks in one show once, and jamming because the gun got dirty was my problem. It went semi-auto at about 190 rounds.

 

I remember once asking Joe at someone's urging, if he included flash powder or some other magic ingredient in his blanks. His answer was No. His blanks are excellent. I scrub and oil everything well between each show, and probably have to replace one blank restrictor--the hole does get burned out to a bigger size over time--about each 18 months. I also don't shoot over 150 shots before cleaning any more, no matter how many gangsters/coppers are still standing as potential targets.

 

That's very good news. It means your flash and noise is only coming from the powder, not from something with more corrosive potential.

[Sarge]

This is the first time I have heard this info. Also a good posibility that he got enuf unhappy responses about the flash powder that he quit putting it in his reenactor blanks?

He still loads his blanks way hotter than necessary on everything, as far as I know. The BFA hole size for all of his blanks that I'm familiar with is larger than for anyone elses blanks. I know of guys who have had problems with their weapons after using his blanks for a while. I have only bought 45 blanks from him, but have gotten them from else where for the past 3+ years.

Sarge

 

I've used Swanson blanks 3 to 6 times a year for 18 years on two rebarrelled 1921s. I tried to shoot 200 blanks in one show once, and jamming because the gun got dirty was my problem. It went semi-auto at about 190 rounds.

 

I remember once asking Joe at someone's urging, if he included flash powder or some other magic ingredient in his blanks. His answer was No. His blanks are excellent. I scrub and oil everything well between each show, and probably have to replace one blank restrictor--the hole does get burned out to a bigger size over time--about each 18 months. I also don't shoot over 150 shots before cleaning any more, no matter how many gangsters/coppers are still standing as potential targets.

 

That's very good news. It means your flash and noise is only coming from the powder, not from something with more corrosive potential.