Round Nose Lead Ammo? Work Ok In My M1 Thompson

[v188]

I haven't gotten around to reloading yet, but with the price of ammo, I'm guessing a Dillon is in my future. That said, I've found some good prices for RN lead 45. I've only ever shot FMJ 230 grain, and wonder if some of your RKI's, could opine on whether I should buy the RN Lead for plinking ammo?

 

I hate to buy more than a case the first time, until I know whether it'll work ok.

 

Thanks in advance.

[v188]

I guess rereading my post, I wasn't clear. I don't reload. I want to know if I buy loaded RN lead ammo is if will work in my M1.

[FireMerc]

As far as I remember the consensus here is that RN Lead is the premium fuel for the Thompson. If the lead is hard enough it won't foul and because it is softer than Copper it will put less wear on your barrel.

 

I personally have only reloaded 230 Gr. JRN for the pistol and Thompson, however PhilOhio has almost convinced me to start forming and loading my own lead bullets.

 

There however has not been a consensus on the type of press to use for reloading...however once again I'll state that I have a Dillon 550B and could not be happier. I load my own 9MM, .44Mag, .45ACP & .450 Marlin and once you start you'll find that the quality is far superior to any commercial ammunition. The reloading becomes almost as enjoyable as shooting.

[PhilOhio]

v188,

 

Yes, by all means shoot the RN lead. Ditto to what FireMerc said. If you search the archives here, you will find tons of really useful info on various loads preferred by board members, including me. It's much easier on your gun than hardball, and it is reliable and accurate.

 

The rule of thumb is, if it runs in a 1911 pistol, it will run in a Thompson. That's the way it was designed.

 

My only caveat is that if you are not going to make your own bullets, and buy them or the reloaded ammo at a gun show, you are rolling the dice on what lead alloy was used. Too many of these guys are cheating on the expensive part of it, the tin. You may get soft bullets which lead your barrel or compensator, and then incorrectly conclude that this is the nature of lead bullets in Thompsons. It ain't. So if you buy at a show, cross examine the seller rather closely.

 

On the other end of the equation are such commercial products as the LaserCast brand of lead bullets, containing a small percentage of silver. The ore is from mine tailings out in Colorado which just happens to contain the silver. The maker unconditionally guarantees that these will not lead a barrel, even at centerfire rifle velocities.

 

I've been loading nothing but my own bullets, cast from roughly the Lyman #2 alloy, for 39 years. They can't be beat. I would use nothing else in a Thompson. But if money is no object, a guy could buy Sierra or Hornady jacketed bullets and keep installing new barrels every now and then. The shooting results would be about the same; they do a great job penetrating paper targets and watermelons, also.

[Shattered]

The shooting results would be about the same; they do a great job penetrating paper targets and watermelons, also.

 

Zombies... don't forget the Zombies.

 

Be aware of too hard a lead bullet. Too hard will lead the barrel from the chamber up a few inches then be clear on out the barrel. Reason is the super hard lead won't form and allow jet hot gases up the sides of the projo melting from the chamber up a bit. Too soft will lead the barrel about halfway down the barrel to the bore.

 

You need a good middle ground casting and then it's a matter of not over loading which will also cause excessive leading.

 

Like Phil says, if done correctly, you can keep leading to an acceptable minimum.

 

[Whiskey Brother]

The shooting results would be about the same; they do a great job penetrating paper targets and watermelons, also.

 

Zombies... don't forget the Zombies.

 

Be aware of too hard a lead bullet. Too hard will lead the barrel from the chamber up a few inches then be clear on out the barrel. Reason is the super hard lead won't form and allow jet hot gases up the sides of the projo melting from the chamber up a bit. Too soft will lead the barrel about halfway down the barrel to the bore.

 

You need a good middle ground casting and then it's a matter of not over loading which will also cause excessive leading.

 

Like Phil says, if done correctly, you can keep leading to an acceptable minimum.

 

I've never had any problems with leading in my Thompson, and cast lead handloads are all I ever shoot in it. I prefer the Lyman 200 grain semi-wadcutter myself, as the velocity and accuracy out of my gun is just a tad better than the 220 grain roundnose, but both function flawlessly thru my gun, and handloading them myself only costs about 2 bucks for a box of 50. (If that...)

[Shattered]

I've never had any problems with leading in my Thompson, and cast lead handloads are all I ever shoot in it. I prefer the Lyman 200 grain semi-wadcutter myself, as the velocity and accuracy out of my gun is just a tad better than the 220 grain roundnose, but both function flawlessly thru my gun, and handloading them myself only costs about 2 bucks for a box of 50. (If that...)

 

I did.. for a while. I had a bunch pretty much over the limit for bowling pin matches. The rounds were too hard first off. Didn't think you could ever be too hard on the lead. I was getting leading in the first 3 inches of the barrel. Then, on top of that I tipped the can a bit on the powder charge. Excellent in a 1911 for bowling pins, but streaked the hell out of the M1 barrel.

 

Pretty much squared away now, just thought I'd put that lil' warning out.

 

[PhilOhio]

...Like Phil says, if done correctly, you can keep leading to an acceptable minimum...

 

What Phil says, is that you should be able to keep leading to zero, if you have the right alloy, lubricant, loading, and know what you are doing.

 

[Shattered]

What Phil says, is that you should be able to keep leading to zero, if you have the right alloy, lubricant, loading, and know what you are doing.

 

Ha! What Shattered quoted was that zero leading is acceptable. :agree:

 

[PhilOhio]

What Phil says, is that you should be able to keep leading to zero, if you have the right alloy, lubricant, loading, and know what you are doing.

 

Ha! What Shattered quoted was that zero leading is acceptable. :agree:

 

Well, I guess I'll drink to that. Whatever Phil says, I usually go along with it.

 

[mike in pa]

Did anybody chrono their 230 LRN loads out of their Thomson to see what velocity it takes to fully cycle the action?

[PhilOhio]

Did anybody chrono their 230 LRN loads out of their Thomson to see what velocity it takes to fully cycle the action?

 

Functionality depends upon recoil energy, not velocity. You can somewhat reduce powder charges with the 230 grainer and it should still function O.K.; even more so with the M1 or M1A1, which have no Blish locks.

 

And you can use a clipped, reduced strength spring, if you want to shoot even milder loads at a low cyclic rate.

 

Or shoot a heavier bullet with a reduced charge, using the standard spring...also getting a lower cyclic rate.

 

You can make the Thompson do just about whatever you want. All it takes is a little experimenting. But don't experiment with the loads themselves; i.e., stick to the powder charge/bullet weight recommendations of reputable reloading manuals.

 

Once again, a good rule of thumb is that if it is an acceptable load for making a 1911 pistol function as a semi-auto, it is fine for a Thompson. And as for safety, vis a vis pressures and so forth, the Thompson is far stronger and safer than the 1911.