40sw conversion barrel experiences

[ethib]

For those that have or do shoot 9mm through conversion barrels how is the reliability? Would you trust it for home defense? What guns have you converted, with what barrels manufacturer, and have any been better than others?

[Monkeywrench]

I have .40 to 9mm conversion barrels for my P226, P229, M&P compact and XDM full size. Reliability is ok, not perfect. I wouldn't recommend them for home defense. A 9mm in a .40 breech face is not ideal. If you get the correct recoil springs and magazines you may well get as good reliability as you would from the factory barrel. If you shoot it a bunch and it works well for you and you're comfortable with it then you can make a decision from that. My barrels are Sig factory, Storm Lake, and Lone Wolf.

[Waffleobill]

I use a Sig P226 .40 exchange kit, of course it came with the slide and barrel. I have never had any issues.

[71MUSTY]

I bought a 9mm slide and barrel for my M&P 40c. Have never used it, just keep it on the safe just in case I someday run low on 40 cal ammo.

[Bill Steele]

I have run a lot of rounds through my G35 with a Lonewolf 9mm conversion barrel. I use a lighter recoil spring and G35 mags, with this combination I would say it is every bit as reliable as any of my stock 9mm Glck guns I have owned.

I think KKM makes the best aftermarket barrels, but the Lonewolf I have used seem to work fine and offer great value.

I would use an aftermarket barreled gun in SD if circumstances required it, but I certainly wouldn't plan on it. But then, a handgun is pretty low on the list of weapons I would bring to a gunfight, if I had the luxury of time to choose.

[JTROKS]

Lone wolf 40-9 with my G35 and it runs just fine with factory ammo. The chamber was a bit tight for my regular reloads and suffered failure to fully chamber. I reamed the chamber with a standard reamer and run my brass though a small base die. Problem solved.

[Divehobo]

Efk Firedragon 40 to 9mm conversion barrels work fine. No issues, run great. I have used them in Sig's and Springfield Xd's. I have noticed with my Sigs that 9mm and 40 S&W ammo run same sight picture but .357 Sig rounds impact about 1" high at 15 yards

[smak28]

There are folks that have zero problems and there are folks that have encountered problems. The thing to realize is it multiple factors can come into play:

1) Barrel - Does it fit? 9mm slides usually are different size than 40 slides
2) Extractor - Sometimes the extractor is built to extract 40 casing but may not hit the 9mm casing at the sweet spot to eject correctly
3) Magazines - Use 9mm mags and not 40 mags
4) Recoil spring - the 40 spring may be too strong so a lighter recoil spring can help the lower powered 9mm round
5) Ammo - Conversion barrels can be picky with ammo

If you have issues, it may be at least one of these possibilities indicated. Only way to really tell is trial and error.

[JTROKS]

With the long slide of the G35 and heavier barrel of the 40-9 conversion barrel the recoil and cycling was a bit sluggish. I wanted it tuned to 125 power factor reloaded ammo. I ended up with a 13# recoil spring with a recoil rod I machined from a steel rod. I also tuned the striker spring to prevent partial unlock of battery problem induced by the lighter recoil spring vs striker spring weight. The result was a 2.5 lb trigger pull and it cycles softly with 125 PF loads. I did install a 9mm extractor and ejector for more consistent ejection.

Efk Firedragon 40 to 9mm conversion barrels work fine. No issues, run great. I have used them in Sig's and Springfield Xd's. I have noticed with my Sigs that 9mm and 40 S&W ammo run same sight picture but .357 Sig rounds impact about 1" high at 15 yards

There are folks that have zero problems and there are folks that have encountered problems. The thing to realize is it multiple factors can come into play:

1) Barrel - Does it fit? 9mm slides usually are different size than 40 slides
2) Extractor - Sometimes the extractor is built to extract 40 casing but may not hit the 9mm casing at the sweet spot to eject correctly
3) Magazines - Use 9mm mags and not 40 mags
4) Recoil spring - the 40 spring may be too strong so a lighter recoil spring can help the lower powered 9mm round

If you have issues, it may be at least one of these possibilities indicated. Only way to really tell is trial and error.

[RR.44]

I run a Lonewolf 9mm conversion barrel on my G35, no issues whatsoever, I use G17 mags as recommended by Lonewolf.


The stock spring weight on a G34 and G35 are the same 13# spring, so I didn't have to change anything other than the barrel and the mags, oh yeah I put a fiber optic front sight on.

[k1dude]

I have a G35. I bought a Storm Lake 9mm conversion barrel for it, but it shot 2.5" high and right at 10 yards. Thinking it was a problem with the barrel, I sent it back and Storm Lake sent another. It too shot 2.5" high and right.

So I thought it was a problem with Storm Lake. I then bought a Lone Wolf 9mm conversion barrel. It too shot 2.5" high and right.

Obviously the problem isn't with the barrels. It's with my gun. But the stock .40 barrel shoots dead nuts on.

Bottom line is I've spent a ton of money on conversion barrels that don't work in my gun.

[S.P.F.]

There are folks that have zero problems and there are folks that have encountered problems. The thing to realize is it multiple factors can come into play:

1) Barrel - Does it fit? 9mm slides usually are different size than 40 slides
2) Extractor - Sometimes the extractor is built to extract 40 casing but may not hit the 9mm casing at the sweet spot to eject correctly
3) Magazines - Use 9mm mags and not 40 mags
4) Recoil spring - the 40 spring may be too strong so a lighter recoil spring can help the lower powered 9mm round

If you have issues, it may be at least one of these possibilities indicated. Only way to really tell is trial and error.

Exactly my experience, too.

I had to change the recoil spring on my G-27, to shoot 9mm without stovepiping. It still sends a lot of BTF. I may change the extractor and/or the ejector to make it extract to the right of my face.

[pdoggeth]

I have Sig P226 in 40, and I bought a Bar-sto 9mm conversion barrel + lighter recoil springs + 9mm mags. The barrel itself is quite picky with ammo. It had pretty tight tolerances, and certain lower quality ammo just kept producing failures to feed reliably. For instance, when shooting my surplus Tula Brass Maxx -- which has a case that often is over the OAL case length -- I encounter these failures. But using good ammo or my own reloads, it could run reliably. Other barrel makers may have looser tolerances, but I haven't tried them.

It is fun to be able to switch calibers, and this way I can allow less experienced shooters to still enjoy my Sig without them having to suffer through 40 recoil snap.

[wurger]

Zero issues with a Lone Wolf 40/9 barrel in my Gen 3 G35.

No mods to the gun, only shoot factory ammo.

[uechikid]

We have conversion barrels (Factory) for a full size and two compact M&P40s. We have put a couple thousand rounds through them with no issues. Accuracy is as good as the ammo we shoot. I'm glad we bought the 9 barrels, it makes it easier for new shooters.