Uzi Caliber Conversion: .40SW, .357SIG

[Paul556]

I saw a guy post on Subguns last week that he had made a caliber conversion for a full size Uzi in .357SIG and .40SW. Did anyone see that? I am thinking about buying one. I would also like to do one in .40 Super. That would just be a barrel as I have a .45 bolt already. I wonder if the pressures would be too high for a .40 Super and a blowback bolt. Anyhow, I thought it would make nice conversation. Any comments or ideas out there?

 

[KarlPMann]

I've seen a 40S&W setup. It was on a subgun barrel. I was told the thinner chamber area of the carbine barrel couldn't handle the pressures of the 40. So I would guess the same might hold true of the 40 Super. Karl.

 

[JIMBO]

caliber conversions...

I have seen several people convert from 40 S&W to the hotter .400 Corbon but this application has been only in handguns that I have seen, no long guns as of yet that I have noticed.

 

[Top Cat]

357 sig conversion

That's me. The 357 sig conversion is still in the test stage. They will probably be available next week. The 40 S&W conversion will see testing later this year. Only a small production run will be made. If there is a lot of interest the project may go further. The 40 S&W barrels will be offered to the buyers of the 357 sig conversion first. Production cost has been so high (so far) that the project seems doomed to failure. Tooling problems and parts availability problems are making the kits prohibitivly expensive. Unless interest is high enough to justify the price I doubt you will see many kits put into production. I will post on this site and on Subguns.com when testing is complete and the kits are ready to roll. Nothing is leaving here until testing is complete. The goal is 100% reliability with 357 sig, but we'll see what happens. All kits will have a 30 day return policy (for ANY reason). All but shipping will be refunded if not satisfied. If you or anyone else has questions contact me at Slatrom@attbi.com.

 

[KarlPMann]

Do you have any cost estimates yet? Karl.

 

[Top Cat]

Cost estimates in the.....

$325 to $375 range. The first five kits are complete, but the first five kits cost over $300 to produce. Add labor and your way over the projected cost. Once the ball gets rolling I'm hoping the cost will drop. Carbide tooling is required and the failure rate has been high, destroying carbide tools and the parts along with them. Hopefully this will get worked out. If not the cost will have to go up. Checking into more parts sources every day. Been raining here pretty steadily, thats been slowing testing up. Durability is a concern and a poly or plastic buffer is recommended, but the test firearm has shown no problems yet.

 

[KarlPMann]

Will the kits be available in FA and SA configurations? What size bolt will be used? Karl.

 

[Paul556]

That is what I saw. Top Cat, are you making bolts from scratch? What about boring out a 9mm bolt; would the extractor get in the way? What is your high cost item? I have been thinking about this long before you started, but you have the guts to do it. I think the biggest problem you will have is the magazines as I am sure you know from your WTB add you have posted. You may want to look into a Stem mag conversion for the mag well. Or you could do a Sten mag adaptor that would fit in a Grease Gun mag well conversion. There are some guys doing .357SIG conversions with AR15's on AR15.com. Check them out. The brass was ruined when fired using a blowback. It seems the bolt moves back before the pressures drop and the nech bulges out. Do you think you will have the same problem? Glad to see you posting on this topic.

 

[UZI SBR AWC]

I think it best to stick with the std 40 S&W. Pressures are SAMMI'd the same as 41AE. Brass is practically free for 40 S&W. The STEN adapter in the M3 well should fly, as it is common practice for MAC 10-45 with a 9mm upper swap. 9mm bolt should be ok, as I think that is that is what KURT use with the COLT AR system, touches the bolt face I think, and adjust extractor.

Thoughts?

 

[Top Cat]

Hit snag today.

357 sig project problems. Having severe feed issues with store bought 357 sig ammo. Early testing was done with round nose jacketed 147 grain 9mm bullets. Store bought ammo has flat point. Jams against feed ramp in my Vector. Strange thing is I have had success shooting several (but not all) hollow points in 9mm. Could not fire a single shot with the store bought ammo. Also seem to be having magazine issues. The standard 25 round 9mm mags appear to work but hold less ammo and are not real reliable. I will try to modify the barrel and see if I can get the 9mm mags to work reliably. 41 AE mags do not appear to load correctly. I can get about 13-15 rounds in and they work fine. If any more rounds are put in they jam up in the magazine. I'm looking into this. I thought it was a problem with the magazine, but I got a shipment in late yesterday and all mags appear to have the same problem. This is going to slow the project way down. I may have to go with the sten conversion we are working on. I was hoping for a "plug and play" conversion. If I can't get this to work the cost is going to skyrocket. I may be stuck with the 40 S&W caliber only if I can't get the mags to work. 40 S&W seems to be the more sought after conversion anyway. I will keep you guys informed. Someone was asking about the case necks being blown out when fired, I have not witnessed this with this conversion. The case necks are pushed up slightly but it doesn't appear to be a problem I have reloaded them with success. In fact all the early test ammo was fairly hot, and was converted from 40 S&W brass (which isn't as robust as the true 357 sig brass) I highly doubt their will be any problems. Recoil is higher (which is to be expected) along the lines of .45 auto (maybe a little less) If I cannot get the 357 sig conversion to work reliably I will still offer it in a limited number to those who would like to tinker with it with the understanding that they can ship it back in 30 days for any reason as long as they don't destroy it. I think it will greatly benifit from the machined (semi) feedramp. Just so you know, I was told by Vector they will install the machined feedramp in their subgun for $50. Yes that is not a typo. $50 for the feedramp installed as long it is one of their guns. I may need to do this to run the factory ammo. Now if I can only get the magazine problem worked out......Does anyone know if there is a sten conversion redily available? I would love to hear more input on this if anyone has any ideas I'd love to hear them.

 

[KarlPMann]

Chris does a grease gun conversion if you want to try one of those.


http://www.uzitalk.com/forums/showthread.php?s=&threadid=422


His board name is Chris and you can e-mail him through his profile.

I have a Model A with a throated semi feedramp that feeds pretty much everything. At least, everything I've tried. It feeds all 9mm and 45 in semi. I don't know about others. Karl.

 

[Paul556]

I would try the Grease Gun conversion Karl mentioned and adapt a Sten Mag conversion for it. Click here for the Grease Gun to Sten adaptor. http://www.tacticalinc.com/index.html If you want to do it from scratch use an M11 Sten mag well from the same source. You would probably do better making the drop in adaptor work as most of your customers will probably already have the Grease Gun lower. If you get a chance send your Vector off for the feed ramp mod. Take your time. We want it right. I think you are right that the .40 will be more popular. I am interested in both. I also want to see if you could ream the .40 barrel to .40 Super. That would be cool. It would be a nice addition to my .22, 9mm, .41AE, & .45 barrels.

ee

 

[Top Cat]

Hit snag today.

357 sig project problems. Having severe feed issues with store bought 357 sig ammo. Early testing was done with round nose jacketed 147 grain 9mm bullets. Store bought ammo has flat point. Jams against feed ramp in my Vector. Strange thing is I have had success shooting several (but not all) hollow points in 9mm. Could not fire a single shot with the store bought ammo. Also seem to be having magazine issues. The standard 25 round 9mm mags appear to work but hold less ammo and are not real reliable. I will try to modify the barrel and see if I can get the 9mm mags to work reliably. 41 AE mags do not appear to load correctly. I can get about 13-15 rounds in and they work fine. If any more rounds are put in they jam up in the magazine. I'm looking into this. I thought it was a problem with the magazine, but I got a shipment in late yesterday and all mags appear to have the same problem. This is going to slow the project way down. I may have to go with the sten conversion we are working on. I was hoping for a "plug and play" conversion. If I can't get this to work the cost is going to skyrocket. I may be stuck with the 40 S&W caliber only if I can't get the mags to work. 40 S&W seems to be the more sought after conversion anyway. I will keep you guys informed. Someone was asking about the case necks being blown out when fired, I have not witnessed this with this conversion. The case necks are pushed up slightly but it doesn't appear to be a problem I have reloaded them with success. In fact all the early test ammo was fairly hot, and was converted from 40 S&W brass (which isn't as robust as the true 357 sig brass) I highly doubt their will be any problems. Recoil is higher (which is to be expected) along the lines of .45 auto (maybe a little less) If I cannot get the 357 sig conversion to work reliably I will still offer it in a limited number to those who would like to tinker with it with the understanding that they can ship it back in 30 days for any reason as long as they don't destroy it. I think it will greatly benifit from the machined (semi) feedramp. Just so you know, I was told by Vector they will install the machined feedramp in their subgun for $50. Yes that is not a typo. $50 for the feedramp installed as long it is one of their guns. I may need to do this to run the factory ammo. Now if I can only get the magazine problem worked out......Does anyone know if there is a sten conversion redily available? I would love to hear more input on this. If anyone has any ideas I'd love to hear them.