Shooting lighter bullets in .357 mag bad?

[rhatimi]

Hi all,

Just wondering, but I had purchased some factory Remington 125gr JSP UMC .357 mag ammo a while back and have read that lighter bullets in .357 mag can cause forcing cone and top strap erosion. Would this be a problem with this particular ammo, or should I just stick with heavier 158gr bullets.

Once again all comments are greatly appreciated.

 

[KWYJIBO]

I don't see how lighter bullets would cause a problem. Cutting of the top strap happens when the barrel/cylinder gap is too large. If your gun has a gap smaller than about .005 or .006" then you shouldn't worry.

125 grain loads are quite popular in the .357, probably second only to the standard load of 158 grains.

 

[rhatimi]

Thanks for the reply, however the issues that I read about were based on the theory that lighter bullets in .357 magnum hit the forcing cone with more velocity than the heavier ones, which causes more ware. Just wasn't sure if this was only in certain bullet weight ranges.

 

[Jimbo357mag]

Those should not be a problem at all unless you have a very light gun like a model 19 or one of the aluminum frames. There can be some problems with very light bullets and max loads of slow ball powders like H-110 or Lil' Gun. Flame cutting on the top strap is self limiting and won't hurt the gun. Erosion of the forcing cone can cause accuracy problems and cause lead build-up and lead spitting problems. I would stay away from 110gr bullets and just keep an eye on the top strap and forcing cone to see if you can see any problems after a box or two. :shock:

...Jimbo

 

[powder smoke]

No problem shoot em up enjoy. ps

 

[VAdoublegunner]

I think that's one of those historical/anecdotal stories about the hot 125 grainer defensive/police loads being used more frequently than expected in 357 Mag K-frame S&Ws like the Model 19. There was some forcing cone, early onset endshake and looseness issues reported. Thus, the L-frame came into being, arguably one of the finest DA carry/duty revolvers ever made (and I am a big Ruger fan!).

If you are shooting them in any Ruger 357 Mag, including a SP101, I certainly wouldn't worry about any 125gr factory ammo. Or handloads within loading manual specifications for that matter. Ruger built 'em that way from the ground up.

 

[Leucoandro]

rhatimi,

as Jimbo noted, this was more of an issue with the S&W K frames in 357. I need to make sure I use the heavier bullets in my Model 19, and my brother needs to make sure he uses the heavier bullets in is special run model 15 Heavy barrel.

It could have impacted other 357's as well, but I have never heard of the issue in a Ruger steel frame handgun.

The theory behind it was interesting. While I can not remember the details, it had someting to do with lighter bullets moving out of the cylinder faster than heavier bullets, allowing more powder to burn in the cylinder gap area. (this was at least the theory I read, I am sure there are others)

There have been limited reports of flame cutting in the aluminum frame Ruger LCR 38 spl models (357 LCR has a steel frame).


Charlie

 

[GP100man]

The 125s hit the forcin cone & the base is level with the gap at time of peak pressure & maximum affects of erosion & flame cutting takes place .

That said I`ve loaded my share of 110-125gr jacketed & shot em thru Colts & Rugers never a sign !!

 

[maxpress]

An article I read years ago talked about the GP100 with 10,000 rnds vs the 686. basically said there wasnt a big difference from new till the end of the test.

 

[pisgah]

The "light-bullet .357" thing has always ben a bit of a puzzle to me. Yes, there were some problems with forcing cones cracking on S&W K-frames -- but as far as I can tell this was pretty much limited to guns that were fired relentlessly for thousands of rounds with 125 gr. loads. No one seems the least bit concerned these days about such loads in .357 J-frames, and I think the reason is simple -- by the time you've fired enough of them to break a gun, your hand has been pounded into an arthritic claw, and few are willing to go so far.

Certainly, when it comes to N-frame S&Ws and Rugers of any model (OK -- maybe not the new .357 LCR, but we'll see) 125 and 110 gr- loads should cause no worries.

 

[roaddog28]

Hi,

This topic seems to come up at least once a week in almost every gun forum. A lot of gun owners shoot 125gr 357 full power rounds in there revolvers without a issue. But there has been a problem at times with forcing cone erosion and spitting of the forcing cone with a high round count of 125gr full power magnums. The revolver that this happens to is the S&W K frame magnum. But I have read on other forums were Ruger Security Sixes that had high round counts of 125gr wore them out and needed repair. Also, on another popular gun forum a GP100 wore the barrel and forcing cone out shooting a high round count of 125gr 357 full power rounds. The owner claims the revolver is a "paper weight on his desk" now.
The fact is, the lighter grain faster rounds are shorter in length versus the 158gr rounds. The lighter grain rounds don't seal the forcing cone off as well and the result is unburned powder charges escaping out of the end of the forcing cone area and top strap. This can result over a period of time erosion on the forcing cone. How long does this take? I don't know. Personally, I sometimes shoot 125gr rounds in my 357s but I limit my round count. I generally shoot heavier grain rounds in the 140gr to 158gr area. I don't use a 357 round for self defense anyway so my revolvers will never see the kind of round count off the 125gr rounds to see a problem. Also, the revolver needs to be clean after a range session and especially in the forcing cone and top strap are.
Bottom line, I am not going to stay up at night worrying that I am going to damage my 357s shooting 125gr rounds. I would say go ahead and shoot your Remington 125gr rounds. I would say for most owners of 357s they will never shoot that many 125gr rounds to wear there revolvers out.
Here is a link that explains what the lighter grain 357 round does. Now the revolver is a Smith K frame magnum but the information is valid for any 357 revolver.
Howard
http://www.gunblast.com/Butch_MagnumLoads.htm

 

[pisgah]

Another subject that comes up often, particularly with light-bullet magnum rounds, is "flame cutting" of the frame. Don't get me wrong -- I know it exists ,-- particularly with the short-lived .357 Maximum -- and I have seen a small to moderate amount of it in alloy-framed guns that have been shot a lot. But I have owned probably 40 .357 Mag revolvers in the past 40 syears, and have examined and/or fired at least 1000 more, and never once have I seen a single instance of flame-cutting. Minor finish wear in that area of the frame, yes. Buildup of crud right there that LOOKS like flame cutting (but cleans off when vigorously attacked), yes. Real cutting in to the frame? No. And even with the alloy-framed guns, I have never seen a case where I would classify the cutting as anything more than normal wear, unsightly but absolutely inconsequential.

Same with "ruining the chambers" by firing .38s in a .357 Mag gun. Sure, if you never clean it you will end up with a problem. But basic maintenance will guarantee there will never be a problem.

All kinds of self-proclaimed experts have told me horror stories of guns converted in to paperweights by these supposedly horrible problems -- but nary a one has ever been willing or able to show me an example.

 

[mattsbox99]

I have a GP100 with some light flame cutting. I admit I shot full pressure 357 loads through it, and a lot of them. I still do. Its got a lot of use. The flame cutting is a normal thing, and it would take somewhere between 1 and 2 million shots to ever see noticeable wear. I'm not even convinced you would see it that soon either.

 

[MidLife]

I have heard that if there IS flame cutting, it abates after a while and proceeds no futher past a certain point. Can someone explain how that is? Is the erosion only a certain distance?
Thanks.

 

[pisgah]

I have heard that if there IS flame cutting, it abates after a while and proceeds no futher past a certain point. Can someone explain how that is? Is the erosion only a certain distance?
Thanks.

Just physics. As an over-simplified comparison -- if you are standing 5 yards away and I throw a baseball at you, it is going to do you serious (at least painful) harm. If you are 100 yards away, the damage will be greatly reduced -- assuming I can even get the ball to you! .

The erosion is caused by hot gas and abrasive particles. Although their velocity is high, the gases and the particles have very little mass, so they have very little momentum, and the energy dissipates over a very short distance.

 

[maxpress]

it also has a tempering effect on the steel.
Speaking of which...steels have come alot further on the GP100 and L frames since the first K frames were introduced.

 

[Jimbo357mag]

Here is a picture of some flame cutting on a top strap. I got this off the net some time ago. The edge of the forcing cone shows a little roughness.
Notice it is a Smiff.

...Jimbo