Sp101 38sp conversation to 357

[Kleanbore]

read my SP101 manual I got with my .357 mag (Ruger sends the same one for 38 special and 9mm) and no where did it say you can shoot a 357 mag out of their 38 special model.

Of course not. It would not fit. The question in the OP is about conversion.

 

[fxvr5]

SAAMI has .357 Mag max at 65,000 psi,

Where did you get that crazy number?

 

[wcwhitey]

And hurt just as much

Not really! If you load you can step up some .38 loads in that gun as it’s Ruger Strong with top end published data loads that approach .357 easily. If not a loader then Buffalo Bore type ammo is a good solution as it’s only gonna be shot once in a while anyway. Assuming one would go with a conversion it’s gonna cost North of $400 and a few months wait to get it done by a decent Smitty. If done at home then good luck with that!
If stout handloads or Buffalo Bore hurt the hand then a .357 conversion would be pointless anyway!

 

[PapaG]

You cannot shoot a .357 in a 38 or it will blow up.
Even if you could get a round in cus .357s are longer and won't fit.

And you can prove this how? I'd rely on Ruger for the difinitive answer. if the parent gun is offered in 357, the derivative may be a special run for a security company requiring a shorter chambering. That said, I wouldn't rechamber my model 15 to 357 even though it is the same frame as my 19. Different heat treat. My SP101 is built like a tank and I'd bet the version in 38 is no diferent.

 

[fxvr5]

Not really! If you load you can step up some .38 loads in that gun as it’s Ruger Strong with top end published data loads that approach .357 easily.

Which top end 38 Special published data loads approach 357? Thank you.

 

[plainsdrifter]

I don't know, but a thought occurs to me. I have a Ruger 9mm SP101. I believe the 9mm and .357 operate at very similar pressures. I have shot a wide variety of ammo in my SP101, with no issues whatsoever. Cases practically fall out of the chamber, even with some of the hotter stuff.

I've always wondered if major revolver manufacturers would go to the trouble of using different manufacturing processes, other than chamber dimensions, etc. when producing .38, .357 and 9mm cylinders. I've not worked in manufacturing, but would that be cost effective? This, along with the potential for a structurally weaker cylinder accidentally getting into the production of say .357 revolvers requiring a stronger cylinder...

Well with that thought why would a manufacturer make a stronger 357 frame just to call it a 38 special?
It's gotta be cheaper to make a non- magnum frame.
Otherwise they would just make 357s and call it a day.

 

[plainsdrifter]

My SP101 is built like a tank and I'd bet the version in 38 is no diferent.

You'd bet your hand and maybe part of your face? OK

 

[SSBN617b]

I did not post my question to get folks argumentative. I will wait for what my gunsmith advises. After reading posts here I believe my best option is Buffalo Bore 38 spl outdoorsman.
Thanks all.
Mitch

 

[wcwhitey]

Which top end 38 Special published data loads approach 357? Thank you.

Using a Lyman#358156 you can get a 1000 fps just with Unique (5.4 grain at 18000 CUP) and that’s only the first crimp grove and straight from the book. There are plenty of loads using 2400 that will get you faster. What more you need out of a little 101? There are avenues that can be pursued in that gun that you wouldn’t even try in you Dad’s old Colt. 95% of small .357 owners are carrying +P anyway. Not all but very few are carrying 1300+ FPS 158 Grain bullets, Point is that ammo is available over the counter that is 158 Grain SWC’s doing an advertised 1200 fps at +P pressures. And if you look back I said “approaching”! I always said about the little .357’s that just because you can do it does not mean it’s a good idea.

 

[fxvr5]

Using a Lyman#358156 you can get a 1000 fps just with Unique (5.4 grain at 18000 CUP) and that’s only the first crimp grove and straight from the book. There are plenty of loads using 2400 that will get you faster. What more you need out of a little 101? There are avenues that can be pursued in that gun that you wouldn’t even try in you Dad’s old Colt. 95% of small .357 owners are carrying +P anyway. Not all but very few are carrying 1300+ FPS 158 Grain bullets, Point is that ammo is available over the counter that is 158 Grain SWC’s doing an advertised 1200 fps at +P pressures. And if you look back I said “approaching”! I always said about the little .357’s that just because you can do it does not mean it’s a good idea.

The Lyman manual shows that +P load with Unique producing 954 fps, the fastest speed with that bullet. Their +P load with 2400 shows 953 fps, which is not faster.

Lyman's 357 data with that same bullet shows a highest speed of 1363 fps with H110. Their slowest max load with Bullseye produces 1122 fps, but that's pretty watered down.

"Approaching" is not the word I would use to describe those disparate speed comparisons.

 

[Blue Jays]

My inclination would be to obtain similar revolver specifically chambered in .357 Magnum so you have both.
You can then decide which you prefer and then simply sell the other. Or maybe you'll love both and keep both.

 

[NIGHTLORD40K]

Well with that thought why would a manufacturer make a stronger 357 frame just to call it a 38 special?

Administrative restrictions and personal preferences. Also, there is a theoretical accuracy advantage to shooting Specials out of a throated .38 cylinder due to less unsupported bullet jump to the forcing cone, but this is probably unnoticable on a snub-nosed gun. It may make a tiny difference in a target gun.

It's gotta be cheaper to make a non- magnum frame.

It is not cheaper to make two different frames due to economy of scale. If you were only going to offer a Special and no Magum at all, then yes you would want to engineer the frame lighter/ thinner/ cheaper- but that is obviously not the case with either the SP or K-Frame.

 

[NIGHTLORD40K]

My inclination would be to obtain similar revolver specifically chambered in .357 Magnum so you have both.
You can then decide which you prefer and then simply sell the other. Or maybe you'll love both and keep both.

Boom, winner!

 

[wcwhitey]

The Lyman manual shows that +P load with Unique producing 954 fps, the fastest speed with that bullet. Their +P load with 2400 shows 953 fps, which is not faster.

Lyman's 357 data with that same bullet shows a highest speed of 1363 fps with H110. Their slowest max load with Bullseye produces 1122 fps, but that's pretty watered down.

"Approaching" is not the word I would use to describe those disparate speed comparisons.

Symantec’s! Most factory loads are not pushing the 1300 as advertised more like barely 1200. I have seen that Unique load do over 1000 fps personally from a 4” revolver with no signs of over pressure. However, you sharpened your numbers pencil but missed the point! You can make a .38 (Or buy some) that far exceeds the average box of factory ammo. A .357 from his 3” or shorter 101 will lose more that a hundred FPS from the over advertised velocity, I would put $10 your average generic 158 Grain .357 Hollowpoint won’t do more than 1100ish. Just a nature of the powders used. There comes a point that there is not a huge amount of difference in performance. A .38 will never be a .357 but it can be improved upon and the gap closed. If you look at the pressure of the published +P data in Lyman’s you will note that the pressures are still below SAMMI specs for the most part. There is room there in the right gun. Not my thing, I think .38 +P is perfect for my snubbies. I have shot them and owned them long enough that I would not waste the extra money on buying a .357 knowing darn well it won’t get used with that round other than to bring on carpal tunnel. If I found myself in a need for that much extra power and velocity and only had the OP’s gun I would do some research and find a load moving a 125 or 158 Grain bullet at 1000 fps or better. Or better yet just buy a box of Buffalo Bore!

It’s the OP’s gun, it’s his money! As gun people we get caught up on measurements and details that sometimes we forget the intended application of a gun. If it is purely a “just because I can” and the OP has the time. money and patience go for it.

Just a side Edit: there have been plenty of work done in the .38 Special world long before any of us. Treasury Loads certainly approaching or at .357 velocities, +P+, 38/44 etc. It is just that things are somehow watered down these days. I want to note that I am not condoning loading outside published data. It is understood that a bunch of cartridges suffer from anemia in the loading manuals as there are plenty of guns out there that make this necessary. That’s why there is the term Ruger Only loads. I think this is a case that I would load Buffalo Bore and not even entertain a concern on hurting that 101.

 

[fxvr5]

Symantec’s! Most factory loads are not pushing the 1300 as advertised more like barely 1200.

It's not just semantics, and you seem to be rambling and tossing numbers around with no accountability. "Most factory loads are not pushing the 1300 as advertised more like barely 1200. " Specifically what? If you're talking .357 Magnum 158 grain bullets, those from the major ammo makers are rated around 1,235-1240 fps, and they achieve that from my 4" barrel. Who loads a 158 at 1300 fps? Where did you get that 1300 fps number? Thin air? The only high performance (Underwood) .357 Magnum 158 load I've tried pushed a 158 to 1,350 fps from my 4" gun.

Just a side Edit: there have been plenty of work done in the .38 Special world long before any of us. Treasury Loads certainly approaching or at .357 velocities.

The Treasury Load is nowhere near 357 magnum velocities. You really should stop making stuff up.
https://www.shootingtimes.com/editorial/38-special-treasury-load/389102

That’s why there is the term Ruger Only loads.

Ruger only loads are for select Ruger guns that can handle pressure past SAAMI specs.

 

[wcwhitey]

It's not just semantics, and you seem to be rambling and tossing numbers around with no accountability. "Most factory loads are not pushing the 1300 as advertised more like barely 1200. " Specifically what? If you're talking .357 Magnum 158 grain bullets, those from the major ammo makers are rated around 1,235-1240 fps, and they achieve that from my 4" barrel. Who loads a 158 at 1300 fps? Where did you get that 1300 fps number? Thin air? The only high performance (Underwood) .357 Magnum 158 load I've tried pushed a 158 to 1,350 fps from my 4" gun.



The Treasury Load is nowhere near 357 magnum velocities. You really should stop making stuff up.
https://www.shootingtimes.com/editorial/38-special-treasury-load/389102




Ruger only loads are for select Ruger guns that can handle pressure past SAAMI specs.

I could give you specifics all night but to be honest I really don’t like your tone so I won’t keep this going. The point has been made and I am sorry if you don’t see it for what it is.

All this because you don’t like the word “approaching”. Seems a bit petty to me!

 

[Riomouse911]

Where did you get that crazy number?

I misread it, 35,000 psi is more like it.

Thanks for catching my error!

Stay safe.

 

[kwb377]

They are the same gun; one's just drilled for 38 and the other for 357 magnum. I have both; check with Ruger.

I also have both and they're actually not the same...at least mine aren't.

My '99 production .38 French police trade-in SP101 has a cylinder OAL of 1.518", while my '09 .357 version has a cylinder OAL of 1.578". A Speer .357 125gr. GD exceeds the length of my .38 Special cylinder just a smidge.

I suspect that part of the French contract was that the guns be built on the first year smaller frame to avoid officers either reaming the cylinder or swapping it completely and carrying Magnum rounds.

As for shooting .357 out of a .38 SP101...there are no structural/metallurgical differences between the two models.

 

[hdbiker]

Full power 158 grain .357s in my 2 1/8 inch SP101 aren't fun

 

[plainsdrifter]

I'm deescalating this discussion. Do what y'all want.

 

[NIGHTLORD40K]

I also have both and they're actually not the same...at least mine aren't.

My '99 production .38 French police trade-in SP101 has a cylinder OAL of 1.518", while my '09 .357 version has a cylinder OAL of 1.578". A Speer .357 125gr. GD exceeds the length of my .38 Special cylinder just a smidge.

I suspect that part of the French contract was that the guns be built on the first year smaller frame to avoid officers either reaming the cylinder or swapping it completely and carrying Magnum rounds.

As for shooting .357 out of a .38 SP101...there are no structural/metallurgical differences between the two models.

View attachment 1077452

View attachment 1077453

Interesting! Is the .38 cylinder throated/stepped or through bored?

 

[SSBN617b]

Thank you kwb377,
This puts it to bed for me. I was looking for a light weigh option to my GP100 for hiking in black bear, coyote trails. I believe the Buffalo Bore options would satisfy my needs.

 

[Armybrat]

My fresh batch of Norma .38 Special 158 grain appears to be loaded pretty hot at 968 ft/sec:

 

[Varminterror]

You cannot shoot a .357 in a 38 or it will blow up.

Patently false for Ruger SP101’s.

 

[fxvr5]

My fresh batch of Norma .38 Special 158 grain appears to be loaded pretty hot at 968 ft/sec:

From what barrel length?