Any interest in having a .357 Sig barrel for your .40?

[TheTman]

I working on a project with my son the engineer to create a conversion kit that will let you change your .40 Kahr into a .357 Sig, and wondered if there would be any interest among the .40 caliber owners on the forum?

There are none available at the moment, and I was just trying to see if there was enough interest to proceed. What I want to do is a drop in conversion with a longer ported barrel, so that you can tell at a glance which barrel you have in your gun. If you didn't like the port, have it cut off and the barrel recrowned. I think I can get away with having a drop in barrel, possibly new guide rod and recoil spring, and magazines will have to be tested to see if they work with both calibers. Since I have a CW40 on hand, that would be the first conversion kit available. Making 1 or 2 just isn't feasable, but if I could make 50 or 100, it might start making it feasable and affordable. My reason for researching this is that the FPE generated by the .357 Sig is quite a bit greater than most of the .40 loads. My first step would be to contact Kahr and see if they are working on such a conversion, and if they were, then I would end my actions in this matter.

[knkali]

I working on a project with my son the engineer to create a conversion kit that will let you change your .40 Kahr into a .357 Sig, and wondered if there would be any interest among the .40 caliber owners on the forum?

There are none available at the moment, and I was just trying to see if there was enough interest to proceed. What I want to do is a drop in conversion with a longer ported barrel, so that you can tell at a glance which barrel you have in your gun. If you didn't like the port, have it cut off and the barrel recrowned. I think I can get away with having a drop in barrel, possibly new guide rod and recoil spring, and magazines will have to be tested to see if they work with both calibers. Since I have a CW40 on hand, that would be the first conversion kit available. Making 1 or 2 just isn't feasable, but if I could make 50 or 100, it might start making it feasable and affordable. My reason for researching this is that the FPE generated by the .357 Sig is quite a bit greater than most of the .40 loads. My first step would be to contact Kahr and see if they are working on such a conversion, and if they were, then I would end my actions in this matter.

I salute people like you and your son. You are the people that make things possible. Unfortunately, our society punishes them. If one of your barrels fails and causes bodily harm, I hope you have an attorney on speed dial. I dont think anyone here would be so rude to you but guns gets traded, sold and others could be. Sorry, I am a downer. Shoot me now. Like the idea though. I would think having options is a good thing. Please tell me what the advantages are to change caliber.

[Bawanna]

I've always liked the concept of the 357 Sig. It's a feeding dream come true and a fast accurate round. It would be quite a handful in a small package.
When our dept transitioned to 45's they considered the 357 as well.
The chief fired a mag through a Glock and vetoed that plan on the spot, said it just plain kicked too much. I still have most of the left over rounds.
He's not a gun guy and I got a few stories about him for another time.

So I got mixed emotions about it. I guess even though I have a K40 I don't really advocate them.

I do wish you well though. A lot of guys woulf like it alot, I'm sure.

[Barth]

I have an MK40 Elite.
And a Glock G27/40 with G33/357 barrel/mags.

That said, I wouldn't be interested in a 357 conversion barrel for the Kahr.
The MK40 is right at the envelope of power and size I can handle for SD.
It starts to take the skin of the web of my had at about 200 rounds.
Plus the 357 ammo really is harder to get, and more expensive, than 40.
Also, the best SD loadings in 40 approach 357 sig anyway.

Kahrs are sort of a smaller niche market too.
I think that's why Bar-Sto, and some of the other after market barrel
manufacturers, don't make Kahr barrels.

I off and on hear about an effort to try to get a group of poeple together
to get Bar-Sto to make a special one shot run of 357 sig barrels.
But that fades away quickly.

Sorry...

[Barth]

I've always liked the concept of the 357 Sig. It's a feeding dream come true and a fast accurate round. It would be quite a handful in a small package.
When our dept transitioned to 45's they considered the 357 as well.
The chief fired a mag through a Glock and vetoed that plan on the spot, said it just plain kicked too much.

First time I shot my G27 with a 357 barrel I was disappointed in
how much the gun recoiled.
Second time out to the range I dialed it in and was fine.
But the 20 oz 3.5" barrel gun is a real fire breather with that round.
I think it's running 125 gr @ 1,300 fps.
That's really magnum force. And it feels like it too...

[tv_racin_fan]

I'd be much more interested in a 22 conversion for my K9.

[jlottmc]

I'll have to get a Kahr in 40, but I'm down with that, provided that the cost isn't horrible.

[O'Dell]

Sorta reminds me of a deal I was offered this past weekend. That was a S&W M&P compact 40 with both the 40 and 357 factory barrels, night sights, and three mags for $419. Same deal for a FS M&P 40. These are unissued police guns and are essentially NIB. Then I remembered that I have an M&P compact 40 which I don't shoot or carry much. Don't get me wrong, it's a fine gun and has been problem free, but I have better options in 45. Plus there's that 'another ammo' thing.

[TheTman]

I was up late studying the cartridges, and the biggest thing I noticed is that the .357 is loaded to .40,000 Lbs pressure, while the 40 is only loaded to 35,000. That may blow me out of the water right there. Not sure I want to add another 5,000 lbs of pressure to the .40 chamber as it is now. And If I make the chamber bigger, It's going to throw a lot of things out of kilter. Safety has to be the number one priority or I'll just end up injuring someone and I really don't want that on my conscience.
While I would form a corporation to limit my fiscal exposure, in case of a KABOOM, that wouldnt help with my conscience, knowing I blew some fingers or a hand up.

Plus while a few are interested, I'm not sure there's enough interest to pursue the project much farther. I thought it would be cool to have 2 guns in one. As has been stated earlier, the .357 sig has a bit more recoil, and not sure anyone wants more recoil than the 40 already produces. The ported barrel I was thinking of might help some, but I'm not sure it would bring it back down to .40 caliber level of recoil.
I still might look at some other companies conversions. Maybe there is a stronger steel that would allow me to be able to keep the same outer dimensions yet provide the added strength necessary for the extra pressure. I realize most of that pressure follows the bullet out the end of the barrel, so maybe the chamber diminsions are fine. That would be something that would have to be tested.

A .22 conversion would be something to consider and maybe that would sell better. There would be a much less chance of a kaboom injuring someone and dragging me through the civil courts. That would take more engineering than I was wanting to do, but I've got time on my hands to work on it.

Thanks to everyone that answered. I appreciate your input very much. I guess if I am going to pursue this, I'll want to take a look at what is being done with other manufacturer's .357/.40 combinatioins.
Thanks again!

[OldLincoln]

Good thoughts! I like folks who don't leave well enough alone and fix things that aren't broke. I built a career doing that and improved process efficiency saving tons of money. My relatively uninformed opinion is that folks generally buy the caliber they want then find cheaper alternatives to practice.

The .22 might sell better, but would there be enough to push the slide back even with a weak spring. I've wondered about a 45 base with a 9mm conversion. They both would be viable defense calibers but the 9mm is less costly to shoot (and reloads are an option).

[mightymouse]

Interesting experiment and the ballistics of the Sig are commendable. Most of the engineers I used to work with would employ a CYA factor by two and wouldn't touch this for the liability issues alone.

[jocko]

I have to agree with MM on that comment....

[TheTman]

I had the same concerns about the .22 converion Old Lincoln, would the .22 move that slide back enough to cycle reliably, even with a very light recoil spring. It would have a nice "bull" barrel, and a new magazine would need to be made, that would hold .22 and still fit into the gun, I was thinking perhaps of a .22 magazine with a full size shell around it. Trouble is doing all this and making it affordable. I doubt many would pay the price of a .22 conversion for the Kahr when they could get a nice proven design for about the same price.

MM and Jocko, Yes the liability issues are a big hurdle, I think that and all the government red tape is what keeps many new products off the shelf. I'd have to form some type of corporation to keep my personal possesions, and those of the corporation seperate. The liability insurance alone will probably be enough to keep me from pursuing this very far. One guy reloading a cartridge with a cracked case could cause the gun to blow up, and I'd be drug through the courts, even though I'd state very clearly that handloads are not to be used with the conversion kit. I think the chamber is probably strong enough to handle an extra 5,000 lbs as long as it's directed down the barrel. I'd like to beef it up some anyway, possibly using a stronger material to keep the dimensions similiar so the new barrel and chamber will fit the existing slide and frame. It's an interesting diliemma, Kahr has a limited market share, and .40's are much smaller part of that market. Would I be able to come up with a safe design and be able to sell enough to break even? Considering a new CW40 is selling around 350-400 at many places, what would a person be willing to pay for a .357 Sig conversion kit? I see kits fitting Glock and Sig going for $125-150.
With a much smaller market to begin with, I'm not sure matching that price would be possible.
Probably the easiest way to get all this accomplished would be to draw up my design and blueprints, and approach the manufacturers of these conversion kits and see if they would be interested in doing that for Kahrs. I'm doubting with the limited market available that they would be very interested, but perhaps I'd learn a thing or two along the way that would prove useful should I decide to start off on my own.
Right now, I'm rather pessimistic that it would be worth the time and effort, as there seems to be little interest.

[jocko]

well at least ur approaching it with the right attitude. I in no way am saying ur wrong in pursuing a dream either, just take baby steps along the way. As u know the owners manual even on this fourmn is usually the last thing a reader/owner ever reads.

I bought when I first bought my G19 one of those 22 conversion kits. used the fokker about twice and never went to it again.

[Jugchoke]

I working on a project with my son the engineer to create a conversion kit that will let you change your .40 Kahr into a .357 Sig, and wondered if there would be any interest among the .40 caliber owners on the forum?

There are none available at the moment, and I was just trying to see if there was enough interest to proceed. What I want to do is a drop in conversion with a longer ported barrel, so that you can tell at a glance which barrel you have in your gun. If you didn't like the port, have it cut off and the barrel recrowned. I think I can get away with having a drop in barrel, possibly new guide rod and recoil spring, and magazines will have to be tested to see if they work with both calibers. Since I have a CW40 on hand, that would be the first conversion kit available. Making 1 or 2 just isn't feasable, but if I could make 50 or 100, it might start making it feasable and affordable. My reason for researching this is that the FPE generated by the .357 Sig is quite a bit greater than most of the .40 loads. My first step would be to contact Kahr and see if they are working on such a conversion, and if they were, then I would end my actions in this matter.

Old thread, but I would be interested if this ever went anywhere.
Have not shot the exact same gun with both .40 and .357 sig, but I find the .40 to kick MORE!