any body have problems with 40-9mm conversion kits?

[bczrx]

I'm thinking of a .40 M&P and getting a conversion kit to 9mm for long range sessions.

StormLake and BarSto have barrels available. I understand it is almost entirely just a barrel and cartridge swap.

Have any of you done it and, if so, how has it worked?

[Meztiso]

I dont think 40cal ammo is that much more expensive than 9mm nowadays is it? In my area 40cal is only $14 BOX. 9MM IS $12. Not really a wallet buster difference especially if you are only buying 3 or 4 boxes per range trip?

I am still interested in the Storm lake 9mm conversion too since I just picked up an M&P40 the other day myself. Not sure if its worth it if it tends to jam?

[Deadeye Dick]

Originally Posted by bczrx

I'm thinking of a .40 M&P and getting a conversion kit to 9mm for long range sessions.

StormLake and BarSto have barrels available. I understand it is almost entirely just a barrel and cartridge swap.

Have any of you done it and, if so, how has it worked?

A .40 to 9mm swap would require more than just a barrel swap. If I am not mistaken it would also require a different recoil spring, slide and magazine(s).

Now a .40 to .357SIG conversion is just a simple barrel swap. You use the original slide, recoil spring and magazine(s).

[handgunner356]

The M&Ps' use the same spring between the 9 & 40, but the 40 slides are heavier. You would probably need to get a Wolff spring/rod setup with lighter springs to adjust for the different loads. You would probably need the 9mm mags also. The 9mm rim is about .020" smaller so you're counting on the extractor to catch the rim and pull it out without slipping. Might work fine for the range but I wouldn't bet my life on it.


"Hope is not a strategy"

[f9dak9]

I have the Storm Lake 9mm Conversion Barrel for my M&P 40 Compact and Glock 23. Both are drop-in, no modifications. 9mm magazines are required. Run both with original recoil rods and springs. Both work amazing, accurate (better than the stock barrels) and reliable-NEVER a FTF or FTE. Completely convinced of Storm Lake's quality, fit and finish.

[MotorCityGun]

Originally Posted by Meztiso

I dont think 40cal ammo is that much more expensive than 9mm nowadays is it? In my area 40cal is only $14 BOX. 9MM IS $12. Not really a wallet buster difference especially if you are only buying 3 or 4 boxes per range trip?

I am still interested in the Storm lake 9mm conversion too since I just picked up an M&P40 the other day myself. Not sure if its worth it if it tends to jam?

I guess it depends on how much you shoot on whether or not getting a $160 9mm barrel and two $25 mags (approx. total $200 w/shipping) would be worth it. Where I buy my practice ammo, there is a $4 difference between 9mm and 40 S&W ammo per 50 rd box. By my calculation, that means you'd have to go through 50 boxes/2500 rounds of 9 mm ammo to make it worth your while. That's about 25 trips to the range for me, given that I normally shoot about 100 rds per trip.

[bczrx]

Originally Posted by MotorCityGun

I guess it depends on how much you shoot on whether or not getting a $160 9mm barrel and two $25 mags (approx. total $200 w/shipping) would be worth it. Where I buy my practice ammo, there is a $4 difference between 9mm and 40 S&W ammo per 50 rd box. By my calculation, that means you'd have to go through 50 boxes/2500 rounds of 9 mm ammo to make it worth your while. That's about 25 trips to the range for me, given that I normally shoot about 100 rds per trip.

I have almost that much 9 in my lockbox for range trips. When I do go, I tend to go through 2-300 rounds of 9 and 2-300 rounds of .45 each trip.

It would be worth it over 10-20 years, but not in a year.

[HAWKEYE10]

Originally Posted by f9dak9

I have the Storm Lake 9mm Conversion Barrel for my M&P 40 Compact and Glock 23. Both are drop-in, no modifications. 9mm magazines are required. Run both with original recoil rods and springs. Both work amazing, accurate (better than the stock barrels) and reliable-NEVER a FTF or FTE. Completely convinced of Storm Lake's quality, fit and finish.

I didn't know they were making a converson for the M&P. Where are you buying your Storm Lake barrel and magazines? Do they sell them at a place like Midway? Don

[Nor Cal Guy]

Originally Posted by HAWKEYE10

I didn't know they were making a converson for the M&P. Where are you buying your Storm Lake barrel and magazines? Do they sell them at a place like Midway? Don

well i ordered up the storm lake barrel conversion from STORM SW M&P COMP 40SW TO 9MM CONVERSION Storm Lake Barrels Barrel 9MM 3.58" Stainless Conversion Barrel Converts 40SW to 9MM S&W M&P Compact SW-MPC-9MMC-358-OP-00T

and mags from
https://www.44mag.com/product/692/smith_and_wesson


havent gotten it yet but i just sent for it today i also
got several target brand ammo's to try them out and see if theres any feeding issue's etc. Ill post up about them later if you want.

Ammo's
Remington® UMC® Handgun 9 mm Luger 115 Gr. MC 50 rds.

CCI® Blazer® Centerfire Pistol 9 mm 147 Gr. TMJ 50 rds.

Speer Lawman® 9 mm Luger 147 Gr. TMJ FN 50 rds.

Winchester® USA Pistol 9 mm Luger® 115 Gr. FMJ 50 rds.

Fiocchi® Shooting Dynamics 9 mm Luger 147 Gr. FMJ 50 rds.

Brown bear 50 rds. 115 - gr. 9 mm FMJ Luger Ammo

Federal® American Eagle® Pistol 9 mm Luger® 147 Gr. FMJFP 50 rds.

[bczrx]

Originally Posted by Nor Cal Guy

Ill post up about them later if you want.

That would be great. Thanks!

[Nor Cal Guy]

Originally Posted by bczrx

I have almost that much 9 in my lockbox for range trips. When I do go, I tend to go through 2-300 rounds of 9 and 2-300 rounds of .45 each trip.

It would be worth it over 10-20 years, but not in a year.

Id think it would be worth it even over 1 year for you depends how often you go to the range. When i broke it down i was going to save $50-75 per 1,000 rounds. Of course this is all if you even decided to get one

[DAdams]

Any updates on the installs and operational experience.

I swapped emails with SL Technical Support and they indicated it is a barrel swap only (+mags, which I already have).

I have seen the barrels on-line advertised for as little as $120 but the only dealers who have them in stock at around $130.

[SWMod10]

I did a write over on AR15.com about using a factory 9mm barrel in a 40 M&P-

9mm M&P barrel in a .40 S&W-a photo comparison-UPDATE IN OP-Range test - AR15.COM

[Lost Lake]

Factory 9 and 357 fit in a 40. No mag changes are even needed.
Midway lists the barrels for $65, discounts are available.

No spring changes. No slide changes.

[turbo38gn]

I bought the Storm Lake conversion barrel 6 months ago along with a couple mags. Works perfect, no other changes needed, no hiccups, just shoots great. I read the write up using a 9mm barrel from Smith for half the price, I don't doubt it works, but it just doesn't make sense to mess around with a barrel on a gun that wasn't built to work in your 40. Sorry, I was going to try it, I actually have a 9c gun and now that I just picked up my 40c last week, I was going to try it...... but decided it's just not the right barrel. I just ordered the Storm Lake 357 barrel with 2 ports for my 40c, can't wait to try that one. Even though I have a 9c, I may still buy the SL 9c barrel, just because I like how easy it is to carry an extra barrel and have 2 guns or in this case 3 guns.. in one...

[mmc45414]

I tried and tried to get a lead bullet load I liked in 40 and then gave up. 9mm, OTOH, has been no problem. I have a Lone Wolf conversion for my Glock 35 and it works great. I bought it for situations where you know you are going to lose your brass (though 40 is getting to be nearly as cheap as 9) or you just want to plink as cheaply as possible. Not counting brass I think I can reload 1k rounds for about $95 with 9mm lead bullets.

[PD Sgt.]

I swapped out a .40 barrel and magazine for a 9mm barrel and magazine in my compact a month or two ago. No conversion units, just a plain Smith barrel and mag. So far it has functioned perfectly with over 500 rounds of 9mm. All of the ammo has been reloads, with varying degrees of wear on the case rims.

IIRC, the ejector, extractor, and recoil spring are all the same parts between the two. I know beside the feed ramps, the two barrels mic'ed out to within a couple thousandths in all critical dimensions.

My next step is to run a bunch of full power factory defensive ammo through it, probably 147g Gold Dots. Assuming it runs as well through those, I will consider carrying it as a 9mm off duty from time to time.

[DAdams]

Contemplating a 40 to 9 barrel for a forthcoming 40c myself I asked the following question to [email protected]

"I am in anticipation of purchasing a M&P 40c. To allow the use of 9mm then I need only SW-MPC-9MMC-358 and it will fit in the 40c slide?
No further parts or modifications required"?

The Response Was....
"Mr. Adams,
Yes, that is correct".
Regards,
David
StormLake Support

[Lost Lake]

And there are several on this forum that have dropped in the factory S&W 9mm barrel (Midway $66) and had no trouble either. Your money.

[turbo38gn]

Originally Posted by Lost Lake

And there are several on this forum that have dropped in the factory S&W 9mm barrel (Midway $66) and had no trouble either. Your money.

I'm not so sure sticking your tongue out like this is a kids game is really fitting when one is playing with guns... I'm the first to jump on an easy inexpensive way to achieve a goal, but when we are talking guns, I really want to be 100% certain that what I am doing can not result in an accident. We don't usually get second chances with a gun... I read all the threads about doing this and felt pretty confident it worked and I was ready to jump on this one... but then I was talking this up with one of the range officers at Smith and Wesson, he jumped me pretty hard and said not to. It's close, but the bottom line.... it is not the same barrel. I don't want to be the one that finds out the hard way, it was a mistake, 1500 rounds down the road. I'll spend the extra 70-80 dollars... for that matter, I saw a few SL barrels used for sale. If one wants to save a buck search around, otherwise. I want to stay shooting for a long time. I have my 9c and my 40c sitting disassembled on the table in front of me as I type... the 9 barrel fits in the 40, the slides go back and forth, the springs look the same... but the machining is diff.. it's tempting to shoot it... naaaaa.... think I'll just put everything back the way it's supposed to be and just use my SL barrels..

[DAdams]

Then what you are saying is not to use anyones 9mm barrel in a 40?

[turbo38gn]

Simply my opinion, I would only use a barrel that was manufactured to be used in place of a 40. Example, Storm\Lake. People I have spoke to directly at S&W have flat out told me not to use their 9mm barrel in the 40 slide.

[Lost Lake]

Originally Posted by turbo38gn

I'm not so sure sticking your tongue out like this is a kids game is really fitting when one is playing with guns... I'm the first to jump on an easy inexpensive way to achieve a goal, but when we are talking guns, I really want to be 100% certain that what I am doing can not result in an accident. We don't usually get second chances with a gun... I read all the threads about doing this and felt pretty confident it worked and I was ready to jump on this one... but then I was talking this up with one of the range officers at Smith and Wesson, he jumped me pretty hard and said not to. It's close, but the bottom line.... it is not the same barrel. I don't want to be the one that finds out the hard way, it was a mistake, 1500 rounds down the road. I'll spend the extra 70-80 dollars... for that matter, I saw a few SL barrels used for sale. If one wants to save a buck search around, otherwise. I want to stay shooting for a long time. I have my 9c and my 40c sitting disassembled on the table in front of me as I type... the 9 barrel fits in the 40, the slides go back and forth, the springs look the same... but the machining is diff.. it's tempting to shoot it... naaaaa.... think I'll just put everything back the way it's supposed to be and just use my SL barrels..

Whatever.... To each his own. I'm saying people here have done it. If it makes you nervous then don't do it. You think there's a difference in the guns? Or just different barrels? I say it's the barrel. I don't think every gun is made differently. You have them both side by side, tell us the differences between the two receivers.

[Turx]

Originally Posted by Lost Lake

Factory 9 and 357 fit in a 40. No mag changes are even needed.
Midway lists the barrels for $65, discounts are available.

No spring changes. No slide changes.

Yes, the mags fit the gun, but the 9MM bullets, don't work well in 40 magazines.
I bought the Barrel for less than $60, a factory S&W barrel, @ dealer cost. The 9mm mags were $20 - $25 each, factory mags.

[some_guy]

Originally Posted by Turx

Yes, the mags fit the gun, but the 9MM bullets, don't work well in 40 magazines.
I bought the Barrel for less than $60, a factory S&W barrel, @ dealer cost. The 9mm mags were $20 - $25 each, factory mags.

where did you get these parts?

[Lost Lake]

Originally Posted by some_guy

where did you get these parts?

Midway has barrels for around $65.