Flame-cutting powders?

[Buck13]

I'd read some time ago that Lil'Gun is hard on revolvers. Now this recent thread indicts Longshot, too.

http://www.thehighroad.org/showthread.php?t=774024

Are there any other powders to add to the "abusive in revolvers" list?

 

[BaltimoreBoy]

But Buck, is it true? In other words, can it be shown that it is the powder and not just the normal result of use?

Yeah, you get some flame cutting on revolvers with hot loads and short projectiles (say 110 grain for 357).

But even that effect seems to be self limiting. I have an almost 4 decade old Security--six and it hasn't changed as far as I can see in 25 years at least.

It is an interesting point though. Has anyone ever shot so many 'flame cutting' loads through a decent revolver that it had to be retired?

Personally, I doubt it.

 

[Chillydog]

Newby here - but I have read the some of the same comments and have the same question.

I have S&W 686-2 that was my Dad's that looks pristine to my eye. The forcing cone leading edge is nice and square/sharp and there is only discoloration on the top strap. I want to be careful and not abuse it unknowingly.

It has only had 250-300 rounds through it and it's not my primary shooter. More of keep sake from Dad. Given these conditions it may not matter at all. I do know his reloads were imr4227 and with a jacketed bullet, guessing 125s

Gary

 

[Surculus]

Any double-base powder will be a candidate for this list: nitroglycerin burns hotter than nitrocellulose. Performance only comes at a price!

If the flame cutting is bad enough, you can always take it to a 'smith & have them inlay a piece of silicon- or tungsten-carbide where the cutting is worst. Very heat resistant, very abrasion resistant. Should come from the factory that way on aluminum-frame revolvers, as a matter of practice.

 

[steveno]

while some powders may be a little worse than others. the gas cutting is caused by a high pressure gas through an orifice (cylinder gap). there will be focus point of this gas and once it disappears there won't be any more cutting. it will take a LOT of rounds for it to be noticeable (maybe .010 to .020) and it isn't going to be a safety issue. if you are going to shoot a high pressure revolver round it is going to happen

 

[gamestalker]

Flame cutting, gas cutting, however you cut the cake, it's self limiting.

Most around here know me to be the guy that loads and shoots nothing but full house jacketed stuff, and I use Longshot +P 38 spcl., and H110 / 296 .357 and 44 magnum nearly exclusively. Among others, these two powders are well known to be some of the worst for flame cutting. Yet despite having loaded with these powders for a rather long time, decades actually, none of the flame cutting on any of my revolvers has ever exceeded the initial effect. Even the forcing cones on my K frame revolvers show no evidence of erosion after several thousand rounds at max charges.

Back in the early 90's I knew this fellow reloader that decided to clean up the top strap flame cutting, in which he lapped away the pitting and cleaned the surface up smooth. He then shot that SBH 44 mag. over the next few months, stating he had only run about 200 rounds of H110 through it, and the flame cutting once again reappeared, obviously it had cut even deeper than before. The moral of the story here, is leave it alone, don't attempt to lap or other wise clean the flame cut area up, it will only induce further cutting.

GS

 

[Rule3]

I would not base a powders supposed flame cutting based in one post. Other posts on the subject are probably conjecture or anecdotal. Is there any hard data to show what powder does what and is it with certain bullets or loads??

As gamestalker states, it is self limiting. Meaning flame cutting will occur and start and then just stop at certain point. I have some SW PC alloy guns with the Falme cutting shield of stainless on them. Those have not been touched yet, If H110 hasn't torched it I doubt any others will but again that's just my conjecture.

I wonder has any gun actually been cut all the way through?

 

[gamestalker]

Now that's a really good question Rule3, has any top strap ever been flame cut to the extent that it's integrity was significantly effected, or in fact cut through?

I don't know the official answer to that, but I would doubt it's even plausible for someone to accomplish such in a life time, even if shooting thousands of full house 110 gr. jacketed H110/296 loads. I've seen forcing cones badly eroded, but as far as flame cutting to the extent the integrity of the top strap is clearly weakened, I've never seen anything like that before, but that doesn't mean it hasn't happened.

But to reiterate what Rule3 stated, this is based on personal conjecture, not scientific fact.

I've seen top straps bent, or pushed up and out of alignment, this isn't all that unusual really. But whether it was related to flame cutting having depleted it's integrity, maybe, but I personally doubt it.

Maybe someone should do some in depth research on this topic? It won't likely be me though, it does interest me some what, but I'm not the least bit concerned about it.

GS

 

[Rule3]

Here is a older thread:

http://www.thehighroad.org/showthread.php?t=626386

Also, even though it is Wikipedia this mentions perhaps why it occurs. I would tend to agree that a gun with excessive cylinder gap or end shake would have more of a problem.

http://en.wikipedia.org/wiki/Talk:Flame_cutting_(firearms)

Many variables. Bullet weight, type of bullet, velocity or max loads chemical comp of the powder etc etc. The big one, how many max loads are fired in the gun>

 

[Paddy]

I don't know much, but a while back I was reasearching ti revolvers and they were said to commonly get bad flame cutting on the cylinder, and that use of lower power loads accelerated the issue. Higher power loads would burn faster and more completely quicker, reducing the problem? Not certain but seemed to go against some of the theory in this thread

 

[gamestalker]

Ya, I would agree there are a number of variables responsible for flame cutting.

Cylinder gap would certainly be a big contributor.

I have an older New Model SBH 44 mag. I bought new from an FFL, so it's only seen the 296 full magnum loads I've reloaded and fed it. It has a pretty generous .0077" gap, so the flame cut is rather wide, but it no deeper than it was 25 yrs. ago.

OTOH, the SRH having a much tighter gap of .004" has a much thinner cut, yet appears to be maybe be a bit deeper.

End shake, or an over all sloppy lock up could also effect how cutting initiates and progresses. If the cylinder is real sloppy, you might get a wider cut line, and an area extended out beyond the cut line that's been scorched also.

So there are a number of variables that can be experienced, but in most cases, and just guessing, but maybe 99% of instances, it's is simply normal conditioning and appearance for most revolvers. What's more, there is no reason to have it addressed or evaluated by a gun smith.

IMO, as far as having a cut top strap cleaned up, one would need to remove metal until they've gotten beyond the depth of the cut, that could potentially mean taking off maybe .050", maybe more? Then consider that the strap gets cut again, which I'm fairly certain this would be fully expected. So lets say the initial damage created a .050" cut, then the second one is also .050", you now have a top strap that is .1" ( one tenth ) of an inch thinner, that's a significant reduction in structural integrity, IMO.

GS.

But I still contend that it is self limiting.

 

[ColtPythonElite]

I also agree that it is self-limiting.

I have Colt King Cobra that has seen around 30k rounds. The top strap has some minor cutting that doesn't seem to have gotten worse as round count goes up.....I would worry more about forcing cone erosion than top strap cutting. My KC has some erosion that can be seen. It doesn't affect accuracy or cause anything to blowback in my face. I figure it will take another 30k rounds before I will need the barrel set back. Considering it took me 25 years to shoot the first 30k, I am not overly worried about.

 

[Swampman]

The best way to test all these theories and conjecture about flame cutting and its self limiting nature would be to go and buy a brand new, current production revolver in .357 Remington Maximum from Ruger, Dan Wesson, S&W or another reputable manufacturer and start shooting!

Unfortunately, we can't actually do this.

Why?

Because every revolver manufacturer that tooled up to produce one (a very expensive proposition since the long cartridge required entirely new and longer frame designs), stopped production in short order due to excessive flame cutting of top straps.

Maybe it was just due to corporate lawyers getting their panties in a wad, but I doubt it. IIRC this was back in the 80's and the legal departments of firearms manufacturers didn't run things as much as they do now.

I think they quit making those guns and tried to buy back the ones that they'd already sold because the engineers were afraid that flame cutting would eventually weaken the frames enough to cause catastrophic failure and possible injury or death to their valued customers. (Then as now, pretty much all companies prefered dealing with "valued customers" rather than "plaintiffs" or "the family of the deceased").

Incidently, the manufacturers had done extensive testing of their new designs before they released 'em for sale and there were no particular problems noted with flame cutting. Unfortunately, being as how the testers were experienced engineers, gunsmiths and competitive shooters, they loaded up and fired ammunition that made sense. Generally158 to 200 grain bullets and heavy charges of slow burning powder to push them at velocities high enough to reliably drop heavy silhouettes at long range. This was exactly what the guns and cartridge had been designed to do.

The PROBLEM:
Chronographs were becoming a "thing" and prices on them had dropped to a level where a reasonably affluent private citizen could afford one.
Most shooters probably know (or know of) "that guy", sometime referred to as "that nut" or maybe just, "that guy who can clear a crowded range faster than a thunderstorm with extra lightning".

One thought has always held true for this type of shooter/reloader, probably since before they even started making bullets out of metal:

If a fast bullet is good, a faster bullet is BETTER!

The hell with accuracy, sectional density, ballistic coefficients, retained energy, the ability to hit or knock over a steel target at 200 yards or the ability to take game at long range!

Nope, none of that stuff was important!

They had figured out that if you loaded 110 grain bullets in that sucker and stoked it with insane amounts of powder you could make really, REALLY BIG numbers appear on that little electronic box!

And thus died the .357 Remington Maximum.

@ Paddy: I'm pretty sure that the excessive flame cutting on at least one of those Dan Wesson's wasn't due to shooting too many light loads.

I know this because, "that guy" was one of my best friends back in the day.

 

[Rule3]

My general theory on the whole thing is I do not really worry about it

It cuts a little and then stops. The gun will outlive me.

 

[Slamfire]

Powder manufacturers are being driven to produce “cleaner” burning powders. At least half of the reason is that many shooters are too lazy to clean their firearms after shooting, so they want the least residue possible left after firing. The law of unexpected consequences delivered: less residue requires hotter combustion temperatures.

Being obsessive compulsive in this regards, I clean my firearms every time after I shoot them, and before I put them up. While I appreciate less residue to wipe out, it is not a deal breaker unless the residue gums up the mechanisms.

 

[ColtPythonElite]

Eh, a good layer of carbon might help slow flame cutting.....Hey, I just came up with another reason for why I don't clean my revolvers that often.

 

[paul105]

Not always self limiting. The top strap/blast shield erosion shown below continued to worsen until S&W replaced the frame under warranty. This was a S&W 329 .44 Mag in less than 3,000 rounds of predominantly 240gr SWC BB at 1,150 fps or so.
.

.

.

.
I have a FA83 .475 Linebaugh that shows no visible top strap erosion after 15,000 rounds of mostly .480 Ruger level loads.

Also have several other magnum revolvers that show differing degrees of gas cutting that appear to be self limiting.

FWIW,

Paul

 

[Rule3]

Wow, that is bad but shouldn't the sacrificial strap have been replaced sooner?

 

[paul105]

I emailed S&W with the first picture above and asked "is this normal" -- their answer was "yes" -- that was at 1,923 rnds. The blast shield eroded in half and fell off 857 rnds later (2,780 rnds) at which time S&W replaced the frame.

I've had the blast shield replaced several other times before it got that bad. I've had three 329s and have shot around 9,000 rnds thru them -- blast shield erosion wasn't uncommon on the guns I had.

FWIW,

Paul

 

[Drail]

Top strap cutting is self limiting but it's important to remember that if gas is cutting up on the top strap, then it's cutting all the way around the forcing cone at the same time. Some powders will cut worse than others especially when very light bullets are used. Many nice S&W and Pythons and Rugers have been abused by owners who shot tons of light flame thrower loads through them. Don't ask me how I know. Read Kuhnhausen's manuals - lots of photos of forcing cones destroyed by owners who just loved the shoot the "hot stuff". The worst powder I have ever used that did serious gas cutting was Blue Dot. Use anything else. Just stay away from all of the max loads for general shooting. Medium weight bullets at medium charges is all you need. Save the flame thrower stuff for the Fourth of July.

 

[Peter M. Eick]

I would add that "hot stuff" tends to be ball powders (or spherical depending on your manufacturer). Stick and Flakes don't tend to cut as much or really at all.

Think about it a bit. Ball powders burning at high pressures tend to act like sand blast grains as they cross the cylinder gap. Its not so much the flame and gas that does the cutting, its the particles that are carried in the flame and gas that do the deed.

I flame cut my 357 Pre-28 with Longshot in one box of reloads. I went back to 2400 and have not had an issue since or before. Live and learn.

I went and checked my records. This was all done in 50 round of 158 grn Lasercast SWC's with 8.3 grns of Longshot on 1/17/10. It had no flame cut before, and it has not gotten any worse since I went back to 2400 or Unique loads.