100,000 Rounds thru a Thompson

[reconbob]

I was just talking to a guy that does gun rentals - he "caters" machine gun shoots

and customers get to shoot guns and have a little of the Band of Brothers experience.

This guys keep detailed records of the ammo and the guns. I built his Thompson some

years back I asked him how it was holding up. He said that according to his records he

will shortly have shot 100,000 rounds thru the Thompson (M1928A1). I asked if the

barrel was shot out and he said no, it looks like new. Of course, there has to be some

wear and I have seen guns with a mirror bore that had no rifling left. But the guys shoots

only jacketed ammo and gets the cheapest factory ammo available at any given time.

He says they don't clean the guns until they stop working. Is the compensator clogged?

Not al all.

I think one thing in this guys favor is that he only brings 4 mags to a shoot, and the

customer loads them. This limits how hot the barrel can get.

I always thought that jacketed ammo would provide a longer barrel life because

lead bullets get tiny pieces of dirt, sand, metal, etc. that stick to the lube or become

imbedded in the soft lead and - again, on a microscopic level - scrape the bore and

thousand od rounds later you have excessive wear of the bore.

I conclude that shooting your collector grade Thompson - assuming its not #167,

will not harm the gun as long as you shoot ball ammo and do not overheat the barrel.

 

 

Bob

[timkel]

Good to know. I typically take 2 sticks to work with. Sometimes plus a drum. Any round count, after 37 years, would be a wild guess. The only wear is bluing wear in the bolt channel.

Edited November 24, 2015 by timkel

[bug]

Plus 1 on heat and overzealous cleaning as barrel killers..

[buzz]

I never considered that lead ammo might lap the bore with grit. That's an interesting idea.

 

They used to sell this product for "fire-lapping" your bore by firing lapping-compound covered bullets through it.

 

Be interesting to test the theory out.

 

Roll a bunch of lead bullets in vacuum cleaner dirt and then see if they wear the bore faster than copper jacketed bullets.

 

My understanding is that most barrels bite the dust because of cleaning rod wear at the muzzle or throat erosion in front of the chamber.

 

I don't think I've ever see a barrel worn smooth of rifling from ammo going through it.

Edited November 24, 2015 by buzz

[Grasshopper]

Hi,

 

Good to know a Tommy will hang in there with minimal care. I'm all for not cleaning unless necessary. I do add oil from time to time. IMHO, guns get more wear from "care" than shooting.

 

Just as an aside, I've got an Uzi with about 54,000 rounds down the tube over the last 16 years. All cast lead. Last 6000 were "coated". Barrel land diameter hasn't enlarged yet. I never clean the bore as it looks clean all the time.

 

I do stay away from WW-231. I've seen and felt what appears to be sand in the powder residue. It sparkles in the sun when rinsed off with brake cleaner from the gun. I shot WW-231 for awhile with a can and it was eating the first baffle. Just saying.

 

As usual, YMMV,

 

Grasshopper

[cubguy]

I suspected that 50 round drum mag dumps were harder on barrels than 20 round sticks

and have been using this procedure as well (most of the time). Is there a method of downloading

a drum with 20 +/- rounds? This would allow friends to shoot it with a drum & not be able to shoot

more rounds at one time than you choose. Or is this over thinking it?

[brazos609]

I suspected that 50 round drum mag dumps were harder on barrels than 20 round sticks

and have been using this procedure as well (most of the time). Is there a method of downloading

a drum with 20 +/- rounds? This would allow friends to shoot it with a drum & not be able to shoot

more rounds at one time than you choose. Or is this over thinking it?

Load a dummy round halfway through the drum.

[mnshooter]

If you have 20 round magazines handy, I think downloading a drum is overthinking it.

 

More important:

Merle Bitikofer says that you should never attempt to partially load/wind a drum,

as it's the surest way to a broken spring.

Edited November 25, 2015 by mnshooter

[bug]

That would surely be true IF you loaded 20 rnds and wound the drum 9 Clicks. I often shoot sub-50 rnd loadings but wind the drum accordingly.

[reconbob]

Years ago it was thought that rifle cleaning rods should be made of brass so as not to

harm the bore. Over time it was learned that grit and filings became imbedded in the

rod causing harm to the bore and the rods were switched back to steel.

Of course we have all seen the brass Thompson rods but the bore is bigger and

shorter and it is unlikely that the rod will contact the bore as in a small 24" rifle barrel.

 

Bob

Edited November 28, 2015 by reconbob

[john]

When I bought my '28 it had a Numrich replacement barrel on the gun. That was near new and only had a few hundred rounds through it.

I proceeded to shoot several thousand rounds over the next several years, cleaning the gun every few hundred rounds....you can hear them slow down when they start to get dirty. I dribbled CLP between the fins on the barrel and after 100, maybe 150 rounds the oil would start to smoke, telling me to let the barrel cool off.

 

I started to have trouble at the last TCA shoot at Tracy's Pre-TATA) as the bolt would click forward but no bang. Primers were dented but not enough to fire. I figured that the headspace must have been worn just enough to cause the problem as the bolt needed to be rapped back with a mallet to yank the cartridge out of the chamber.

This showed up after my second win at the steel shoot and I was really doing well, but when the gun won't fire, well, two malfunctions and I was out!

I tried to blame the ammo but after checking the chamber later the front edge of the chamber appeared to have worn and since the cartridge headspaces on the front of the rim, well, it just wasn't gonna be reliable anymore (and my .22 kit wouldn't fit that barrel anyway) so I put a new one on and it took care of all the problems. Runs like a swiss clock now (a loud one!)

 

I suspect, as with other guns I have shot a lot, that the carbon in the ash residue is a bit abrasive andeventually will cause headspace to increase (I have a Remington .223 that exhibits excessive headspace (primer backs out.015" but no pierced primers yet) after 6,000 plus rounds, but when the prairie dogs are up, who wants to clean, right?

 

I also suspect that those Numrich barrels were probably not the same quality of steel as the USGI barrels so that would maybe explain the wear.

 

WIth a good bench vise and a barrel wrench, though, a barrel is an easy thing to swap out.

 

john

[Black River Militaria CII]

While the bore of a vintage Thompson might not show wear and tear with occasional shooting or more, the number of squib rounds from all types of .45 should give pause to any one shooting a vintage gun. Thompson barrels are easy to bulge and it only takes on squib to do it. At Knob Creek over the years, there have been quite a few Thompsons, including Colts, offered for sale with one or two rings in the barrel, and every once in a while an owner who claims to not have known about the rings! One very well known collector and former CEO of a major gun manufacturer had a lovely 21AC he was carrying round showing off and taking bids and unknown to him, the barrel was ringed. Not a happy fellow once he learned that it was........

[james m]

I can tell you about my experiences in gunsmithing at our club several years ago. The club had a 28 and M1 as rentals. Since these were rentals no customer ammunition was permitted and the club at that time used MAGTECH exclusively which as I remember it had plated bullets. The guns were cleaned and maintained at least twice a month or more frequently depending upon conditions. Barrels would last between 100,000 and 200,000 rounds