Conversion barrel problems

[Mickeytnova]

Looking for some help from fellow calgunners as I did a search and came up with nothing relevant.

So I recently picked up a .40 to 9mm ported conversion barrel for my p226 and headed out to my local BLM over the weekend in hopes of feeling what all the hype was about (reduced muzzle rise), for some quick fast follow up shots and to break it in.

After about 2-3 shots, I started having a FTE, and stove pipes every round out of the magazine. Switched all 4 magazines I had with me and still happened. Hmm...

I went and reinstalled the .40 cal barrel and shot without a hiccup.

This leads me to believe the recoil spring could be the culprit. Any thoughts?

It is an EFK Firedragon ported conversion barrel
Federal 115 gr FMJ.
Some pics of the pistol.

[ojisan]

The .40 to 9mm swap seems to work only in those guns that have an extractor that can swing over far enough to grab the extractor groove in the 9mm case.
Sounds like your Sig extractor is not grabbing the case.
The case is being blown out of the chamber just the same way as a blowback .22L or .380 auto would, by gas pressure not the extractor pull.
The problem is that without the extractor to hold the case against the breechface until the ejector hits it, the case will just flop around in the breech and the ejector has no chance to work.

[black_pacer_56]

I have 2 P226 in 9mm & 40 SW and I think change your green recoil spring in (40cal) to use the red recoil spring (9mm) because the gas pressure are higher in 40cal loads. After you use the red recoil spring, you FTE & stovepipes should reduce but I don't think your problems will gone because the slide of 40cal pistols are heavier than 9mm slides in p226 FYI

[RoundEye]

I think it's been covered, but you will most likely need to use the corresponding SIG 9mm ejector and/or ejector, recoil spring, and 9mm magazines (if you're not already doing so) to maintain reliability.

[scoobydo]

Ejector is fine. All you need is a 9mm spring. The. 40 spring works only after being well broken in.
Edit**You do need 9mm mags. What I meant was the Ejector is fine.

Here's pics of my .40 with a sig 9mm barrel. Ejector more than clears.
Bottom pic shows the 9mm barrel/casing in the .40 slide assembly.

[003]

I would be very careful about using the same magazines. The allowable dimensions for 9mm and .40 caliber are substantially different.

Depending on your specific magazines you may very well get away with it; particularly if your .40 cal magazines are at the minimum end of the allowable dimensions.

Getting away with it does not mean it is a good idea. Keep in mind, the 9MM is .355, the .40 is a true 40 caliber.

Allowable magazine lip width dimensions are:

9MM .325 to .335
40 Cal .360 to .370
10MM .360 to.370
357 .360 to .370
45 .425 to .435

[JeremyS]

Allowable magazine lip width dimensions are:

9MM .325 to .335
40 Cal .360 to .370
10MM .360 to.370
357 .360 to .370
45 .425 to .435

Might be a rule of thumb or best practices, but different manufacturers will vary wildly from this with perfectly fine results. The part of the slide that strips the next round out of the magazine can be very narrow, and can allow for tight feed lips even with a larger round (scoobydo's last two pictures above show that very well). Some manufacturers have NO difference whatsoever between their .40 and 9mm (and other caliber) magazines. For instance, Mec-Gar mags for the CZ 75 series are COMPLETELY identical in every possible physical dimension (including followers, springs, lips, etc) between .40 and 9 and are wholly reliable in both calibers.

Here's a pic of a 9x19 loaded into a .40 S&W Mec-Gar mag and a 9mm Mec-Gar mag:



Can you tell which magazine is marked for .40? Wouldn't be possible, as they are physically identical measured down to the hundredth of an inch, at which point I assumed that differences are due to manufacturing tolerances.

Mec-Gar is one of the largest if not the largest pistol magazine manufacturer in the world, and they make the OEM mags for Sig, CZ, and plenty of others.

So.... just throwin' it out there. In the OP's case, the .40 mags might have feed lips that are too wide for 9mm rounds!!! I'm certainly not claiming otherwise. But... sometimes that is not the case.




I do start getting weary of caliber conversions when the diameter of the rim gets smaller than what the gun was designed for. You start having extractors that don't lock into the rim well enough and/or ejectors that miss or don't kick the case out in the right manner, or sometimes breech faces that aren't supporting things properly.

Anyway, assuming those things are supposed to work in this case, the .40 is a more powerful round so the recoil spring is almost certain to be stiffer. To get 9mm to reliably eject, you'll (OP) probably require a lighter recoil spring, as has been mentioned.

[Mickeytnova]

Wow, thanks a lot to everyone for all your info.
After reading up, I'm going to go ahead and order a new recoil spring. I've ordered a Wolff 15 lb reduced power spring. I went with it instead of the 16 lb factory one due to it being a .40 cal slide.

I also went ahead and ordered a 9mm 226 rebuild kit midway had for 23 bux and it included a stock 226 spring. So I figured I'd have the benefit of more ways to trouble shoot my problem.

Good stuff on the magazines. I made sure I was using the correct mags...I remember thinking to myself that the .40 and 9mm mags look quite similar when I looked at them in my safe and how I wouldn't wanna mix up the two.

I'll post updates on my situation and hopefully resolve this. From what I was able to shoot that day, it felt really soft. The recoil, quick target acquisition, it was fun! Just a bit frustrating to see a stove pipe ruin your day.