What 40 cal/ 9mm Combo best? Glock/XD/M&P?

I have a M&P40 4" that I got a Storm Lake conversion barrel. I have only put maybe 100 rds. through it. No issues and POI have been the same.

I think the gun itself is something you will have to determine whether it is for you. I had to put an Apex Tactical kit in mine to make it a smoother action pistol.

I acquired a M&P Shield in 40 from a co-worker, and bought a Lone Wolf (Alpha Wolf) conversion barrel for. It has functioned well so far.

9mm M&P magazines fit the 40 styles just fine. But I don't know about the other firearm makers. Hopefully someone can enlighten us on that here.

I was not impressed with either of the M&Ps stock triggers. I don't know if the M&P 2.0s improved them or not. With the Apex, which is at $95ish now, it improved to a smooth trigger. The Shield, I have filed and stone, and made my own striker blocker plunger with a healthy radius for smoother trigger pull.

For the conversion barrels makers I listed, I would recommend them from my experience.

I have a police trade-in Glock 22. It's a good shooter and I got it for not much money (police trade-in). Just for grins I paid $120-something total for a 9mm conversion barrel and G17 magazine from Lone Wolf Distributors. It's functioned perfectly for the 100 or so 9mm rounds I've put through it. When I switched them out back-to-back the 9mm shot just a tiny bit lower than the 40, but that may have had something to do with the bullet weights and powder charges. (I was shooting various cartridges that my FiL reloaded.)

I have a full-sized S&W M&P in 45acp and perhaps slightly prefer it to the Glock.

But to me it's pretty much win/win. They're both accurate and reliable pistols.

I’m kind of confused. Wouldn’t the extractor be out too far to reliably work and the firing pin be in the wrong spot? Isn’t a slide required too?

What am I missing here?

460Shooter said:

I’m kind of confused. Wouldn’t the extractor be out too far to reliably work? Isn’t a slide required too?

What am I missing here?

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The slide is reused with the 9mm. When you manually place a 9mm Luger cartridge in the 40 slide, there is a bit of wiggle and isn't snug. There is usually enough of extractor claw to pick up on the 9 cartridge, but that may vary gun to gun. From what I have read of peoples comments, most have had no problems extracting the 9mm casing. I did read on one forum that a guy said he had 2 extractors break, I believe on an M&P.

I started with Glocks, then switched to M&PS because they felt better. Stuck with an M&P40c and a full size for about a decade.

Then went to Glock due to the G29. Got a G35 and then a G19.

Recently bought a new M&P40c with the safety in hopes that it would be the perfect carry pistol.

The Glocks are more accurate. The triggers are better and cheaper to make acceptable.

The M&P40c gen 1 is more compact than the G19. Mine with an Apex sear and some polishing is at 3.75 lbs and not bad.

It's now my official carry gun.

Thinking about getting an M&P9c barrel and magazine and seeing how it works.

Both platforms are good. Glocks are a bit more accurate and way more options for customization. M&Ps feel a little better and are a little more compact (gen 1).

It all comes down to what feels better for you and which attributes you value more.

460Shooter said:

I’m kind of confused. Wouldn’t the extractor be out too far to reliably work and the firing pin be in the wrong spot? Isn’t a slide required too?

What am I missing here?

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I have the same question...I guess I have SIG on the brain.

460Shooter said:

I’m kind of confused. Wouldn’t the extractor be out too far to reliably work and the firing pin be in the wrong spot? Isn’t a slide required too?

What am I missing here?

Click to expand...

As far as the firing pin goes, the head difference between the two cartridges is .030" +0/-.010". That gives a chance of the center of the 9x19 being off centerline at .020", taking in account of half the -.010 tolerance.
Of course one has to consider any existing weak primer hits and how well the tolerances of the slide is.

My Sig P226 shoots 9, 40, 357, and 22lr.

you can buy the slide exchange kits. Kinda pricey though.

What I find really cool is that mags made by MecGar. the 40 mags hold 9mm and the 9mm hold 40.

One mag for 3 calibers is pretty sweet.

Huntolive said:

OK, but I own a Glock 20, that apparently cant be switched to 9mm,...

So which would be better to get 9mm barrel for: 40 Cal XDm Compact (3.8") or 45 XDm full size?

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I'll suspect your Xdm 45 has the same problem as your G20, you can't put 9mm in that size gun.

Note, .40 S&W, .357 SIG, and 9mm are all the same length, basically. If you start with a gun in .40S&W you can usually convert those to either .357 SIG and/or 9mm.

The 10mm, .45 Auto, .38 Super, 9x25 Dillon, .400 Corbon, etc., are all longer cartridges than .40S&W, .357 SIG, 9mm.

Huntolive said:

OK, but I own a Glock 20, that apparently cant be switched to 9mm, and own 40 cals already (XDM and RugerSRc) and compact 9 mms, as well as XDm 45.
So Glock conversion is out.
So which would be better to get 9mm barrel for: 40 Cal XDm Compact (3.8") or 45 XDm full size?

I'm not buying another 9mm pistol.

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Thinking off the top of my head, I would go with the .40 cal. Someone correct me if I'm wrong, but the 45 would probably require strong recoil springs and definitely a different slide.

JTQ said:

I'll suspect your Xdm 45 has the same problem as your G20, you can't put 9mm in that size gun.

Note, .40 S&W, .357 SIG, and 9mm are all the same length, basically. If you start with a gun in .40S&W you can usually convert those to either .357 SIG and/or 9mm.

The 10mm, .45 Auto, .38 Super, 9x25 Dillon, .400 Corbon, etc., are all longer cartridges than .40S&W, .357 SIG, 9mm.

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All good points!

I'm biased, but I'd go Glock. I've had a few 9mm conversion barrels over the years for my .40 Glocks and it works well.

I don't think you can go wrong with a Glock or an M&P. I like the way the M&P's feel better so that's my preference, but I think they're equally good from an objective standpoint.

Some say the M&P40 magazines work with the 9mm barrel. I haven't tried that. When I bought that barrel (Storm Lake) from grabagun.com, I was able to buy 9mm 17 rd. factory magazines at $17 each.

I like the glock combo's. Cheapest aftermarket barrels. cheap mags and holsters. i have the g22,g23 and g27 with 9mm and 357 barrels

My M&P .40 M2.0 Compact 4" NTS is a mighty soft shooter (softer than a G23) and was a great deal at $299.99 New from S.O.S. They tend to rotate which M&P they have on sale every week or two. Shouldn't be a problem getting aftermarket conversion barrels and I now the mags are in every LGS and Big Box with used ones readily available as well (or at least will be as soon as they restock from shipping them all to Cali).

The M2.0 Trigger is a lot better than the M1.0 trigger but Apex can fix the M1.0.

I think the ex-KSP G35-4 that is readily available right now makes a great conversion gun for .357 Sig. We got 1430 fps average out of factory 125 gr JHP. It would also make a great inexpensive game gun with a drop in aftermarket 9mm barrel.

Really it's not that much difference. By the one you shoot the best.

Huntolive said:

I just noticed that Springfield has a new XD Defender out in 9 m m which is going for $300 brand new and free shipping!
That tempts me to just get another gun.
About how much does a 9 mmA Barrel cost for Glock 27 (is the Glock 27 40 cal?) or barrel for an XDM 40 in 9 m m?

anybody heard anything about or have any experience with or have the new Springfield XD Defender ? if I got one it would be the 4-inch version.
How do they differ from a regular XD?

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Not sure where you are getting a barrel for the glock’s. But lone wolf can go on sale for less then 100 for a 40-9 conversion barrel

It's cool to be able to switch calibers back and forth. Conversions that work great for me:
Glock 20 10mm: Lone wolf 357 sig conversion bbl
HKP2000 .40: HK357 sig bbl
SW Shield 40: Alpha wolf 9mm conversion bbl (also changed to 9mm mag although the .40 mag will work)

When I'm done shooting, I always switch back to the original bbl.

d'zaster said:

It's cool to be able to switch calibers back and forth. Conversions that work great for me:
Glock 20 10mm: Lone wolf 357 sig conversion bbl
HKP2000 .40: HK357 sig bbl
SW Shield 40: Alpha wolf 9mm conversion bbl (also changed to 9mm mag although the .40 mag will work)

When I'm done shooting, I always switch back to the original bbl.

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I never tried the 40 mags for the 9 with the shield. I think I bought the same barrel as you for the shield.

As for replacing with original barrel after a range trip, I'm guilty of not switching back once. Took the M&P40 out once to test some 40 S&W reloads. The 1st round jammed up. I did the usual clear. 40 cal. bullet wedged in a 9mm barrel. Gotta learn from that. Besides, I don't think I would carry or depend for defence with the conversion barrel unless in a pinch.