L-O-N-G-S-L-I-D-E .357 Sig

[gnappi]

I finally finished my build of a longslide .357 Sig 1911 on my para ramped 5" RIA 10mm. Fitting the slide and adding a proper slide stop, extractor and new mag release was well worth the substantial expense and time spent. I spent just about the cost of the whole RIA 5" hi cap gun on the stuff I wanted but the range trip today made it well worth it.

For anyone who has fired the Sig cartridge in a little sub 4" auto you know the muzzle blast and sheer volume of the detonation is a bit distracting. But in a 3 lb. 4 oz. pistol with a 6" non-ported barrel these effects are nil, and it shoots more like a 5" 1911 in 9mm. Really.

Feed, extraction, ejection, and accuracy was better than I had hoped for. The one down side is the rather stout loads I made that work well in my Sig P229 (139gn LRN wax lube in a re-formed .40 case) would not latch the slide on the last round with the longslide, no surprises there. These loads are upper mid level and there's room to go up from there. Just about every longslide I have or have had (without porting) and have had likes a bit more powder to get all that extra slide mass going.

Anyway, the factory Federal Classic 125gn fMJ worked flawlessly and my next trip I'll use the same 139gn home cast bullets but instead of wax lube, I now use powder coating which should let me goose the loads up even further toward the end of the load data tables.

As a level set, I also took my P229 and touched off a number of rounds of both ammo types I brought along, and the experience was again no surprise, the muzzle flash lit up the walls of the booth and got others on the range to peek over at me. :-)

Why it is no company ever made a longslide .357 Sig now surprises me. This cartridge "may" perform well in Bambi secret agents hands, but it hurts her too much, and now the Sig is fading away, even Sig has for the most part abandoned it.

[Kenk]

Nice write up, Thanks!

[DenStinett]

Very nice !

[cwlongshot]

Probably two years back now. I herd Glock was gonna disco the Gen3 guns completely.

I have been wanting a G24 for ever waitin' to see if a used one popped up. Leafin' thru the KKM site I grabbed a 6" 357 Sig bbl. then ordered that G24 brandy new.

WOW WOW WOW!!  I have a few lil 357's and like the caliber but MAN O MAN DONT A 6" barrel wake up velocity!!!!! 

It is a favorite coyote pistol!!!  I can shoot about 4/5" leaning on a tree out past 75/80 yards!! Probably hit a dog in chest past 100 if I had a steady rest!!

CW

CW

[The_Shadow]

I have 357 Sig barrels for the G-29 and G-20
The 29 is stock length and the G-20 is also.  I have looked for a 6" for the G-20 but not to be found...YET!
I had a guy the was going to make some barrels for the S&W 10xx series but that fell through.  Two of those were to be 357Sig for the 1006 and the 1076.

[gnappi]

While only 5" and not a longslide in today's parlance of calling a 4.25" handgun "full size" (like they call midsize cars full size now) I bought a 5.25" threaded .357 Sig barrel (comp already in house) for my S&W M&P .40 cal. I'm looking forward to testing it alongside my all steel sig barreled guns.

[cwlongshot]

I did a little 357 SIG Video last month, hope ya find it interesting.. 

https://youtu.be/VOMd3vY-4EY

CW

[gnappi]

Thanks for that. I wouldn't call the Sig  cartridge unsung... it had scads of support from LEO and civilian shooters but the little barrels made muzzle blast fierce, and recoil for many was too much to handle.

The Sig is the most feed forgiving cartridge I ever shot before the 9x25, that alone makes is an ideal SD choice, add to that your illustrating its performance gain in longer barrels just adds to the  mystery why it fell out of favor for the 9mm. I guess Bambi secret Agent won that argument :-)

 

[challer61]

Can you share the details of your build, sources of parts and services? I have the 6" RIA 10mm and what to build it out for 357 SIG and possibly 9x25