New 1927 Thompson jam-a-matic?

[JSnover]

Bought new in October, made by Auto-Ord/Khar. Took it to the range last weekend and put four boxes of factory hardball through it. Failure to feed about every 5th round. I made sure the stick magazine was fully seated, the action was clean and lubed. Is this common? My first thought is to polish the feed ramp but I don't want to start off in the wrong direction. Can I expect it to improve after it's broken in or are there some known issues with these?

[GabbyM]

I know nothing about the 1927.
But for half the auto pistols I've purchased new they needed a good cleaning with full disassembly.
My worst was a S&W 659 with lots of aggregate from the grinding on stainless steel parts. Could not even get a case to slide up under the extractor.

So I'd say take it apart then scrub with stiff bristle brush and solvent. Magnifying glass to look for burrs.

Next thing is you said “the “ magazine. If you've only tried one mag then that could be where your problem lies.

[Ben]

I'd try a 2nd magazine.

Wouldn't be the 1st time I've seen a bad mag cause a semi auto to behave in this manner.

Ben

[Bret4207]

The only guy I know with a Thompson is Starmetal Joe. You'll find him over on Accurate Reloading, probably in the Cast Bullets section. He might be able to help you.

[SPRINGFIELDM141972]

Jsnover,

Is the bolt difficult to open? I had a similar problem with a M1 version from auto ordinance. Mine came from, believe or not, the rear sight screws bearing down on the bolt and slowing the return of the bolt to battery. My failures to feed were not consistent like every 5 rounds as you described, but it might be a place to look. I this helps.

Regards,
Everett

[leadeye]

I had one of those 27 years ago and it jammed all the time as well. Tried a variety of things but finally sold the gun. I was amazed that it was as bad as it was considering how reliable the full auto Tommyguns are.

[JSnover]

I'll break it down and check the screws, look it over for any debris. It only came equipped with one magazine and I decided not to buy more new ones since a friend of mine has a stockpile of them, already 'field-tested.' Thanks guys!

[rockrat]

On my semi-thompson, I actually had to grind the feed ramp a bit, as the front edge of the cartridge would catch on the edge and not feed. Worked fine after that.