M&P 40-9mm Storm Lake conversion barrel "FTE"

[drew-67]

Hi, I have been experiencing a few malfunctions using a storm lake 40-9 conversion barrel..Out of three boxes of 50 I have been getting 1 or 2 FTEs, stovepipe and or jamming.
This was with Federal 9mm 115 grain aluminum case ammo.. So then tried Remington 124 grain brass ammo and had the same thing happen after 48 rounds a FTE..
*Note so far only has happened during faster shooting!
Accuracy is awesome, but don't like having any malfuntions..Is this to be expected with the conversion barrel? any suggestions? (I am already using a factory 9mm magazine as well)
I've had well over a 1000 rounds out of the stock 40 with absolutely no issues/malfunctions..
Thanks for any help!

 

[Shield9mm]

usually those failures are not related to the barrel only, it could be some other factors, like magazine, recoil spring, extractor, ejector, ammo...

 

[GerSan69]

I just looked up cartridge dimensions. 40 S&W has a diameter of .424" at the rim, but the 9mm is .392. I'm not an expert, but it just seems to me that a breech face and ejector that's made for the larger cartridge might not always work with the slightly smaller one.

 

[Woff]

Well it looks like you have most bases covered. Try a brand new 9mm (blue) recoil spring assembly. My kkm conversion works flawlessly.

 

[drew-67]

Well it looks like you have most bases covered. Try a brand new 9mm (blue) recoil spring assembly. My kkm conversion works flawlessly.

I do already have a blue recoil spring that came with stock 40 S&W..I understood the recoil spring to be the same on both the 9mm and 40.
Thanks!

 

[Walt Sherrill]

I've had a number of different conversion barrels in a number of different guns (Glocks, SIGs, and FN), and the conversion barrels have all been tweaked/designed to assure that the extractor properly catches the rim of the conversion round.

Sounds like an extractor problem. You might try talking with the barrel maker's customer service folks and see what they say. It might also be the ejector, which probably is different in a 9mm model -- but that typically ISN'T an issue with conversion barrels, unless the ejector is damaged or gunked up, etc. Make sure the extractor or ejector are not chipped or damaged and seem to work properly.

Just manually racking the slide should show that the extractor has the potential to hold a case against the breechface as the slide goes back and that the round hits the ejector properly. The problems you describe: jams, double feeds, stovepipes are typically the problems that occur when the extractor loses it's grip on the case BEFORE the case hits the ejector.,

The fact that you're only having problems when firing rapidly is puzzling. Cycling is generally about MECHANICAL relationships, and not speed...

Aluminum case ammo is a problem for some guns -- and the cheap stuff is often problematic, if only because it tends to be less precisely made. (Rounds will perform differently as you move through a box.)

With many guns in the same model line, the recoil springs are often the same, with the slides modified (typically heavier or lighter) to control velocity; the .357 or .40 slides are heavier than the 9mm slide -- so swapping recoil springs isn't always an option.

I don't see how mags could be an issue -- as the extraction process typically doesn't have much to do with the mag... but there may be something something going that I don't understand. (Feeding problems, yes, but extraction problems?)

 

[drew-67]

I've had a number of different conversion barrels in a number of different guns (Glocks, SIGs, and FN), and the conversion barrels have all been tweaked/designed to assure that the extractor properly catches the rim of the conversion round.

Sounds like an extractor problem. You might try talking with the barrel maker's customer service folks and see what they say. It might also be the ejector, which probably is different in a 9mm model -- but that typically ISN'T an issue with conversion barrels, unless the ejector is damaged or gunked up, etc. Make sure the extractor or ejector are not chipped or damaged and seem to work properly.

Just manually racking the slide should show that the extractor has the potential to hold a case against the breechface as the slide goes back and that the round hits the ejector properly. The problems you describe: jams, double feeds, stovepipes are typically the problems that occur when the extractor loses it's grip on the case BEFORE the case hits the ejector.,

The fact that you're only having problems when firing rapidly is puzzling. Cycling is generally about MECHANICAL relationships, and not speed...

Aluminum case ammo is a problem for some guns -- and the cheap stuff is often problematic, if only because it tends to be less precisely made. (Rounds will perform differently as you move through a box.)

With many guns in the same model line, the recoil springs are often the same, with the slides modified (typically heavier or lighter) to control velocity; the .357 or .40 slides are heavier than the 9mm slide -- so swapping recoil springs isn't always an option.

I don't see how mags could be an issue -- as the extraction process typically doesn't have much to do with the mag... but there may be something something going that I don't understand. (Feeding problems, yes, but extraction problems?)

Thanks for the thoughts..
It may be just coincidence that it has happened during faster fire, than during slow,,not sure.
But I do know for sure that I have zero issues when shooting with the stock 40 S&W barrel, regardless of ammo used or how fast, one hand two hand etc.
So thinking it is most likely directly related to the difference with the conversion to 9mm.
Thanks again!

 

[Woff]

If you are not opposed to turning this into a money sink... the apex extractor is never a bad idea, and can only improve situations. M&Ps 9 and 40 extractor and ejector are the same.

 

[LoneStarWings]

I've had bad luck with my storm lake barrel until I did a lot of polishing. KKM much better out of the box. YMMV, just my experience.

 

[drew-67]

I contacted Storm Lake customer service this morning,,the gentleman I spoke to was very helpful and suggested I apply for a return label on their website and send it to them to inspect and repair etc.
After filling out and submitting the required info I was approved and emailed a label to return the barrel. Hopefully it will come back with no issues
Thanks for all the helpful replies!