cutting in top strap

[a45gunslinger]

I have a 454 casull , I noticed the top strap appears to be getting cut by gasses right above the cylinder gap..I don't use max loads. Is this normal? I have less than 500 rounds thru it.

[PaulS]

The pressures and resulting gas velocities should not be high enough to produce gas cutting on your Casull. The 357 Maximum has higher pressures and the reputation for gas cutting was blown out beyond proportion. My brother owns and shoots a revolver in 357 max. at near maximum loads and after years of shooting there is no measurable cutting. You may be seeing some discoloration due to the carbon in the gasses but if you are actually experiencing cutting you should first have it checkedby a pistol smith and if he agrees then send it back to the manufacturer. Your frame may have missed a final heat treatment.

[jro45]

On any of my revolvers there isn't any cutting. I shoot max loads at all times. Like PaulS said it may be some discoloring that looks like a cut from the gases and powder used.

[Jerry Lester]

I've got a stainless 357 Blackhawk. It showed definate flame cutting after a couple thousand rounds of full house loads. It ultimately ended up cutting maybe .003"-.004" deep in the center, and stopped after that.

This gun has way more than 20,000 rounds through it now, and it doesn't show any signs of the cutting getting worse.

For what it's worth, the cyinder/barrel gap in my Blackhawk is a tight .003". From my experience, the wider that gap is, the more likely flame cutting is noticed, but I've never seen "any" revolver that suffered from it enough to hurt the gun.

[a45gunslinger]

It is definitly getting cut.. :?   thanks for your comments guys

[Lone Star]

Gas cutting of the top strap is common in many revolvers using high-pressure cartridges.  Several manufacturers currently address this by making a small machine cut in the frame above the gap during the making of the frame; this cut reduces the gas velocity when it hits the frame and reduces/eliminates additional cutting.  Because it is so often normal, I would not be concerned - your frame will not be weakened nor will it be cut in two.  Cutting usually stops after a depth of a few hundredths is reached since this reduces the gas velocity/temperature and its cutting potential.  

The 357 Maximum has higher pressures...

No, the .454 is factory loaded to far higher pressures than the old .357 Max was (50,000 cup vs 40,000 cup), and it produces a greater volume of gas; one would assume that it would exhibit more flame cutting of the frame than the .357 Max did....but it is still not enough to worry about.

[unspellable]

ANY revolver (Except a Nagent) will produce flame cutting on the under side of the top strap above the cylinder gap.  The question is not should it exhibit flame cutting, but whether the flame cutting is excessive.  In most cases, the flame cutting will be rapid during break in and then slow down to the point where it is imperceptible.  Of course hotter loads will cut faster.  But I would say that so long as it is no more than 0.003 inch deep, the cure is to take a stiff shot of bourbon and be happy.

Incidentally, I don't know that the 357 Maximum runs any higher pressure than the 454 casull.  The 357 SuperMag runs the same pressure and flame cutting was never an issue.  The problem with the 357 Maximum factory load was a poor choice of bullet weight and powder type.  The 357 Maximum was derived from the 357 SuperMag.  As is typical when the factories take a wildcat commercial they have to fix what ain't broke.  Remington tried to drive a fairly light bullet to hyper velocities, something the 357 SuperMag was never intended to do in the first place.

[PaulS]

I have to print a retraction here - Off the top of my head I said that 357 Max used higher pressure than the 454. I had to look it up and this is what I found:

357 Max:  48000 cup

454 Casull:  65000 PSI

You can't convert the two to the same so i did more research.

357 Max:  40000 PSI

454 Casull:  65000 PSI

Speer and Hodgdon both hold their loads to a lower pressure of 45000 cup in their manuals (Speer says it is to maintain bullet performance.)
Speer lists a maximum charge of H110 as 37 grains and Hodgdon list a maximum of H110 as 36 grains. The Speer manual states that they use the lower pressures but the Hodgdon manual does not. Thus loads from the manuals (these two at least) have the following results:

357 Max:  48000 cup
454 Casull:  45000 cup

There is no doubt in my mind that the 454 Casull can take more pressure than the 357 Maximum but something there scares the powder and bullet manufacturer - I wonder if there is some way to find out what it is.

[Lone Star]

The reason for the lower pressures used by some manual publishers is no secret.   Freedom Arms specifically warns owners NOT to use high pressure loads with 'soft' bullets.  Most of the .451" bullets available to handloaders are designed for the .45LC and are too soft.  They can upset in the barrel forcing cone and are known to cause high pressures and/or to break apart, leaving bullet fragments in the forcing cone.

The bullets used in FA factory ammo are very tough with thick jackets and hard cores.  A few bullet makers are now offering similar bullets for the .454.  Nosler lists full-pressure loads, but only with their tough Partition bullets.  Ditto Hornady with their 240/300XTP Mag bullets only.  Sierra splits their data between the soft 240HP (low pressure) and the very tough 300FN (high pressure).

[a45gunslinger]

in another forum it was said that"  ball powders are one cause, actually sandblasting the frame" very interesting thanks for your input fellas

[unspellable]

Above, the 357 maximum is said to run 48000 cup which I find plausible.  At the same time it is said to run 40000 psi This doesn't add, piezo measurements invariably show higher figures than cup measurements.  Probably a typo, or like me, the fingers get ahead of the brain when typing on these forums.  Do we have better numbers?

[454PB]

The reason for the lower pressures used by some manual publishers is no secret.   Freedom Arms specifically warns owners NOT to use high pressure loads with 'soft' bullets.  Most of the .451" bullets available to handloaders are designed for the .45LC and are too soft.  They can upset in the barrel forcing cone and are known to cause high pressures and/or to break apart, leaving bullet fragments in the forcing cone.

The bullets used in FA factory ammo are very tough with thick jackets and hard cores.  A few bullet makers are now offering similar bullets for the .454.  Nosler lists full-pressure loads, but only with their tough Partition bullets.  Ditto Hornady with their 240/300XTP Mag bullets only.  Sierra splits their data between the soft 240HP (low pressure) and the very tough 300FN (high pressure).

I've read these warnings many places, including Freedom Arms. I find it interesting that I regularly shoot my homecast 310 grain BHN 15 gas checked bullets at 1600 fps with no problems and excellent accuracy.

As to the gas cutting of the top strap, if you shoot any revolver enough, you will see some degree of gas cutting.