21 replies to this topic

[Sgt]

Sten Guy and I took my sick Thompson out today. We used both Winchester ammo and also the South African stuff called, Denel PMP. As you may remember from previous reports, the bolt intermittently failed to seat the round, resulting in light primer strikes. Sten suggested that I hold the grip firmer. Sure enough, it fired flawlessly, both with bursts and also with a drum dump. He then showed me how to make it malfunction. When he held it looser, the gun would misfire. So have you guys ever exprienced this kind of thing?

We continued to burn about 400 rds that day, with no problems and with pretty decent accuracy. Actually there was a minor situation with the drum, It would sometimes not fire on the last round.

[Grey Crow]

That's odd never heard of such a thing. But hey if it werks, hang on to her tight!

[catnipman]

I've had the exact same experience with my TSMG.
Firm grip and it shoots fine; weak grip and it behaves exactly like yours. Misfeeds not fully chambering and light primer strikes. The light primer strikes are basically a form of not chambering all the way.

I figured this out based on the fact that when I shot it, no problems, but when others would shoot it, it wouldn't shoot worth a darn. I finally guessed that newbies were being very tentative in holding onto the gun. When I tried a loose grip, then I had the chambering/light strike problems too. When I instructed them to take a firm grip, then their problems disappeared.

[Sgt]

Catnipman--
I was wondering if this could be caused by weak recoil spring as others have mentioned. In other words, maybe a stronger spring makes the forward momentum of the bolt to be less dependent the otherwise neglible buffering of the shooters grip.

Hey, I'm just happy it works. I even improved my accuracy with the better technique.

[SecondAmend]

While not with the Thompson, I have seen a number of shooters, experienced as well as new, have failures to cycle properly with the Luger and with the Glock 36 (compact .45 ACP). When told to tighten up their grip, the guns cycled properly.

As Newton's Second Law says, every force has an equal and opposite action force. Unless there's something (i.e., the grip of the shooter) to act against, the internal force of the gun can not react properly hence can not cycle properly.

[catnipman]

I'm certainly not an expert, but I suspect several things can contribute to this problem based on my own experience with my TSMG. The basic issue seems to be the amount of force needed to chamber a round vs. the amount of force the bolt has coming forward.

Several things were contributing to my problem, including an undersized chamber on a NAC barrel, as well as a weak recoil spring. However, even with these two fixes, a firm grip is still required for trouble-free shooting with my TSMG. So there may still be some other issue remaining. BTW, I think another thing that could contribute to the problem would be underpowered loads.

However, when you think about what happens with a loose grip, you can see that if a TSMG was right on the edge of required chambering energy vs. forward bolt energy, then a loose grip stance causes enough of the bolt recoil energy to be consumed by propelling the entire gun backwards, that the forward bolt energy will be reduced enough that it might not have enough energy to fully chamber a round.

I'd be very interested in people apparently without this problem performing some loose-grip experiments with their own TSMGs and reporting the results.

BTW, the problem seems to be worse with box magazines than with the drums, as it seems like it takes more energy to push a round out of a fully loaded box magazine than a fully loaded drum.

[Sgt]

Guys, thanks for the comments. That inertia thing does make sense. What still confuses me is that more don't complain about it and mention this as a possible solution. Maybe you guys have stronger fingers from all those years of choking the Thompson.

[sten guy]

SGT,

Thanks for letting me shoot the Thompson. A drum dump is a lot of fun..

The Sgt. has a really nice Savage '28 ( that I tried to buy from him at least twice yesterday)..

I think the Thompson does require a little different technique than other more modern weapons. I seem to have the best luck shooting from the hip.

The range time re-kindled my lust for the Thompson. I hope P.K. sends mine home soon....

STEN

[21 smoker]

Hey,join the club...sten guy...mine is due back anytime now...then I can give you guys a range report...
what is being discussed here is called `limp wristing`...that is what instructors actually refer it to...there are a lot of pistol automatics that won`t function if not held securely when fired,so it is probably possible with a thompson...me,I was always afraid of dropping it so I would squeeze the dogs##t out of it.just my .02,

[The1930sRust]

I've always heard it called "limp wristing" when shooting pistols. Having a light grip lessens the pistols ability to chamber rounds by robbing its momentum. Guess the same thing could happen in a TSMG...

[Norm]

Whatever you do, DONT' "LIMP WRIST" THIS!!!

[SecondAmend]

"Mad Max" special.

[Sgt]

Sten--
Yea, thanks for the great shoot. We'll do it again with the M1s.

[sten guy]

I can't let off the trigger until I change magazines.

STEN

[OldFalGuy]

Real common occurence just like the described limp wristing with about any automatic-semi or full, with the small exception for those made to go on soft tripod mounts.
Been a long time since I fired a Thompson (mine is on the way) and good to read about the "squeeze it like you mean it" method and not to tickle the trigger as some (moi) are want to do.
Should the heavy trigger pull ever be reduced? Or is the heavy trigger an integral aspect for the Thompson to function?

Mark

[PK.]

I’m not buying it.

The limp wrist syndrome is an accepted phenomenon in handguns- recoil operated especially. To apply it to SMG’s is a stretch at best.

I can read the Tec Manual now “while the enemy is trying to kill you, be sure to hold your TSMG just so…..”

For one thing, most all SMG’s are not recoil operated but blow back or retarded blowback and weigh (in the case of a Thompson)10 times what a pistol does. Some of us don’t have arms that weigh as much as a TSMG.

Any respectable SMG will work one handed, two handed, and in many cases, no handed.

Trigger control is one thing- base function is another.

Ralph is not a liar or embellisher (as far as I know) and I believe him when he says he can make his otherwise unreliable gun work by manipulating the way he handles it. That only means that he has found a way to address a symptom- he has not solved the problem.

I felt the need to write this because the idea that the TSMG is not reliable in less than perfect circumstances or requires special consideration in handling simply is not true, and I could not allow that premise to stand.

Respectfully submitted, IMO

[Sgt]

PK--
Even though the characteristics of this Thompson improved 99.9% with a firmer grip, I was also thinking along the same lines as you, that something is causing the phenomena. In other words, its probably not a normal thing to happen. If you noticed in several of my posts, I was probing whether this was a standard occurrance. What confused me is why I didn't hear of more cases of this, if it was indeed a typical characteristic. Glad you jumped in to confirm my nagging doubts.

[bug]

I have a Savage '28 that would not run with Fiocchi ammo. It consistently would yield light primer hits every 3-5 rounds. Followed with S&B the gun ran flawlessly. Another mag of Fiocchi and the problem recurred. I stopped using Fiocchi.

When I have the gun running well and switch to my left hand, it just plain will not function. If I had to defend myself left-handed with this gun I had better swing it at the bad guy.

Some of the things I tried were new recoil spring, new firing pin, new hammer assembly but the Fiocchi would not perform for me.

I shot mostly wheelguns and my 1911. I have a tendency to let the recoil take my hand back and up when shooting them. My first experience with a Glock 23 was a disaster. Every round was a misfire untill I learned to hold it firmly. The owner of the gun could not believe his eyes as the gun ran perfectly for him. There is something to this recoil/inertia thing.

Just for kicks, try shooting your TSMG with your weak hand and see what happens.

Bob D

[PK.]

Phil,

The line “Trigger control is one thing- base function is another.” was intended to separate the two issues- I did not address the trigger control issue at all. It’s apples and oranges to me.

[Grey Crow]

PK,

I envisioned a similar thought.

A wounded solder not being able to defend himself because he can't hold the gun firm enough.

There must be more to it than that, but at least it's firing at the present time.

My Colt Defender functions no matter how you hold it, my 14 year old daughter gets quite a wrist twisting from it.

I think it was discussed earlier that accuracy was less when one had a bulls grip on the gun.