When the rebate started I got a 40 for 344.00 before
the rebate. I don't stock 40 S&W. Just for S&G's I
loaded up a K of 180 gr lead flat points. the gun loves
it. With rebate the gun'll be 269.00

Today I got notified the bay had a 9mm barrel, I bought it.
When that one comes in I'll shoot 9mm. it cost 150.00.

When it's all said and done I'll have another dual caliber
pocket pistol. That will give the Glock 23/19's company.
I just wish SIG's were as easy.

And I still won't have to stock 40 S&W.

I hope you've done your due diligence on putting a stock 9mm barrel into a Shield mean't for a .40 caliber. In a FS M&P there is a slight difference in the barrel hood which could cause the barrel not to lock up. It might be the same in a Shield.

And different magazines? (Don't know if the Shield 9 and .40 use the same type.)

__________________
Alan
SWCA LM 2023, SWHF 220

Do you have to change the recoil spring?

__________________
"He was kinda funny lookin'"

My Glock 9mm conversion barrel is a bit thicker than the stock barrel to account for the wider barrel of the 40. Also, the ejector may need to be changed for proper action. Especially, if you are going to carry it as a 9mm.

Looks like it'll work just fine.

Well, there must be a problem with my M&P 40 full size. I have over 55k 40 through it and about 20k 9mm through it and it hasn't blown up yet. Maybe I should send it back to S&W and say "whaddup"?

In my research on this with the 40 S&W Shield:

The magazines are physically the same dimensions
between the 9 & 40 with the exception of the creases
on the 9mm magazine that preclude using the 40's in
a 9mm mag. You can use 9mm in a 40 magazine
but not the other way around.

Recoil spring assemblies are the same.

The barrel hood on the 40 is about .02" wider than the 9.
This means you can use a 9 in a 40 but not the other way
around with stock barrels. At practical ranges that slop
doesn't make a difference.

FWIW Remsport mfg. makes a couple drop in barrels for the 40
to 9 conversion, click the link below:

Other Barrels

If I had known this I might have gotten the threaded one to
use with the 9mm SWR can the Glocks use.

The zeros will be a little different because of bullet weights
& velocities (usual stuff you see due to bullet weights
within a caliber.)

When It comes down to it I "might" get a threaded barrel
from Remsport and I'll probably get a few 9mm mags
once I wring out the use ability of this set up.

Let me play with this a while and I'll let ya'll know what
I find out.

All 40-9, unless specifically a conversion barrel, will have the barrel hood clearance issue. My 40SW Sig 2022 has 500 rounds through its 9mm barrel, but if I want to shoot 9 I bring a P320.

There are many here who've done the Shield-specific 9mm barrel in the 40 without issue, that I considered doing the same when giving my first Shield to my gf. A competitive shooter with an M&P (non Shield) 40 and 9mm barrel reported changing the extractor (due to chipping) 3 times, about 1-5k rounds per change, til leaving it chipped and still functioning as an extractor. He concluded it's an issue for high-volume use and wouldn't do it again.

Barrel to slide lock up I don't think is a big issue (on my Sig 40 w/ 9, accuracy did not suffer) as much as chipping the extractor.

My Sig's extractor is thick, my Shields... not so much. You're right almost everything is the same between the 40/9 slides, except the barrel hood width and therefore the extractor will be grabbing with "nails vs fingers."

Took pics of my 40 SP2022 slide with the 40 barrel and 9mm barrel.

40 barrel, slide, snap cap.


9mm barrel and snap cap, 40 slide


Shield 40 vs 9mm barrel




Debating on this very conversion, I ended up with a PC Shield 9 instead of a 40, but due to aftermarket barrel options now (Remsport, as 'serger' mentioned, and True Precision) I still consider trading my PC Shield 9 for a 40.

My last last concern is damaging the puny extractor on the Shield.

EDIT: Took these earlier.

Shield 9mm extractor:


Sig P320 9mm extractor:


Sig SP2022 40S&W extractor:


If the 40SW Shield extractor was as beefy, I may have given the 40-9 conversion a go, but from what I read they have the same part number.

greeenteeee,

My shield 9mm barrel and 40 barrel are the same width as yours. I ran a Winchester 115 grain white box thru it yesterday. Not a problem. But that's a pizz poor sample.

What I would like is to see the slides depth of cut for the 9mm slides extractor. If they have the same PN then why aren't there reports of chipping with the 9mm Shields and not the 40's. If the extractor is the weak sister here then Smith's engineers must have compensated some how with the extraction process between the 9 & 40. Otherwise we are back to the chipped extractor.

I will say when I did the Glock 19/23 conversion I replaced the extractors and ejectors with 9mm parts. And on one of them I also did the whole striker assembly and spring. (That was over kill).

I haven't really looked at my SIG P229's set up yet but all the 9mm barrels are in SIG's price range (high out of sight).

I don't see why the 9 and 40 Shields would have extractor issues. Having the same part number doesn't mean that they are getting the same grip on the casing.

The extractor in the 40 slide is trying to grab a 9mm casing that is smaller in diameter.

9MM is .355/.356 dia.
.40 is .401

Say you're doing parallel bar pull ups (40 slide/barrel/casing). The distance btwn parallel bars moves inward slightly but your hands stay where they are at (hands:extractor:arallel bars:casing).

I'm not against the conversion, I'm neutral to it because I picked up a second Shield due to the rebate and I was torn between the 9mm or 40+9mm barrel.

That Sig 40SW I posted has 500 rounds of 9mm through it as of that photo. Say it had 5k rounds of 9mm through it, maybe THEN there may be an issue... I have never swapped an extractor which is my hesitation on the conversion. Maybe I should just learn.