Regarding forcing cone issues and such with these guns:

I know it's been covered before here. But I want to get very specific about my particular gun and the particular ammo I'm considering for carry.

I'm purchasing a very pristine stainless steel model 66 "combat magnum". It is a 2 1/2" snubbie.

I plan to shoot almost all .38 ammo in it as far as practice goes. I plan to carry 125gr. Corbon DPX for self defense. I plan to only shoot enough to sight in the gun - followed by maybe a cylinder (or at most two) of the magnums per month just to make sure the sighting in is proper for my carry purposes.

I plan to stick religously to that schedule and not abuse the gun.

The issues, as I understnd them, have to do with "hot" loads of 125gr. type ammo. My ammo is considered a very "mild" load for .357. Steven A. Camp, for instance clocks it at less than 1200fps from a 4" barrel. The box lists around 1300fps. But they do not clock that fast for anyone that I know of.

These are less speeds even than the 158gr. loads of yesteryear and that is for 125gr. bullets. I understand it's not the configurabion of the bullet (a 125gr. vs. 158 and above). Rather - the culprit is very high loads of powder that is doing the damage. (Also, these DPX rounds use modern "low flash" powders which are different than the older powders - as I understand these things.)

SO.......with those very particular perameters in mind, am I safe to use those rounds occasionally? Again, 90% .38 ammo and at the most a half dozen or so mid-to-low power loads of 125gr. .357 per month just to be sure of the sight picture.

I, again, will be faithful to this pattern for as long as I own the gun. I have other guns to abuse if I feel the need to get kicked.

By the way - I'm 63 yrs. old. I've wanted this gun for carry for a long time. I plan to shoot it until I meet my maker.

There you go! Very specific- what do you think? What are the odds of not hurting the gun in the next 20 years of shooting? (After that they can blow the gun up for all I care.)

Regarding forcing cone issues and such with these guns:

I know it's been covered before here. But I want to get very specific about my particular gun and the particular ammo I'm considering for carry.

I'm purchasing a very pristine stainless steel model 66 "combat magnum". It is a 2 1/2" snubbie.

I plan to shoot almost all .38 ammo in it as far as practice goes. I plan to carry 125gr. Corbon DPX for self defense. I plan to only shoot enough to sight in the gun - followed by maybe a cylinder (or at most two) of the magnums per month just to make sure the sighting in is proper for my carry purposes.

I plan to stick religously to that schedule and not abuse the gun.

The issues, as I understnd them, have to do with "hot" loads of 125gr. type ammo. My ammo is considered a very "mild" load for .357. Steven A. Camp, for instance clocks it at less than 1200fps from a 4" barrel. The box lists around 1300fps. But they do not clock that fast for anyone that I know of.

These are less speeds even than the 158gr. loads of yesteryear and that is for 125gr. bullets. I understand it's not the configurabion of the bullet (a 125gr. vs. 158 and above). Rather - the culprit is very high loads of powder that is doing the damage. (Also, these DPX rounds use modern "low flash" powders which are different than the older powders - as I understand these things.)

SO.......with those very particular perameters in mind, am I safe to use those rounds occasionally? Again, 90% .38 ammo and at the most a half dozen or so mid-to-low power loads of 125gr. .357 per month just to be sure of the sight picture.

I, again, will be faithful to this pattern for as long as I own the gun. I have other guns to abuse if I feel the need to get kicked.

By the way - I'm 63 yrs. old. I've wanted this gun for carry for a long time. I plan to shoot it until I meet my maker.

There you go! Very specific- what do you think? What are the odds of not hurting the gun in the next 20 years of shooting? (After that they can blow the gun up for all I care.)

I believe that part of the problem 125 gr. bullets have is that they are actually in flight before they hit the forcing cone and peen the bottom of the cone right above the flat spot. I don't know, but am guessing that the Barnes X bullet used in DPX may have more bearing surface with the barrel because a solid copper bullet has to be longer than a lead one. If this is the case, the peening might not happen and the lower power may take care of the hot gas part of the problem. These are the things that pop into my head and I'm really curious what others think. I'll guess that your gun will be fine and that the 125 gr. issue doesn't apply to DPX, but it's only a guess.

FWIW Speer 135 gr. SB .357 might serve your needs just as well. Good luck, Marvin!

That dpx is so expensive, I think you'd have to shoot enough ammo to have paid for a dozen replacement guns before you'd get forcing cone issues with this mild stuff.

I actually have some velocity matching mild reloads that I practice with rather than actually use the expensive bullets. At least I have used them before while practicing. Probably will with the new model 66 as well.

I'm pretty sure the effect would be the same with almost any modern powder as with the powder used in the DPX ammo itself.

I'd like some input into this aspect as well from the guys here.

Glad you brought this up.

I use duplicate handloads for my carry ammo in various calibers. Sometimes the handload's bullets aren't exactly the same weight as the bullets in the carry ammo either. I design the handloads so that the recoil impulse is similar and the point of impact always comes out close enough not to matter. For example, if you used Speer 135 gr. SB, you could probably get away with using 148 gr. wadcutters. YMMV because I use full underlug barrels and my 629-1 is ported. That might be helping me keep the points of impact close together.

Sounds like you have plenty of plans, and that's good. however, you are overthinking it in my opinion.
You are 63, no offense but your kids will still be shooting that gun with no erosion issues.
It's a big overblown flap that would take many many years and thousands of full blown 125's.
I doubt you will ever come close to that.
Unless you make it to age 90.

I was issued several Model 19s with 2.5 inch barrels and our standard round was a modest .357 load with a 125 grain bullet.

We shot so much we wore guns out but I never had the kind of problem you are concerned with. I thnk it is a non-issue.

Enjoy the gun and don't worry about it. You are at the point in life where you can have a lot of fun with it. It is going to last a long time.

flop-shank made a very good point that often goes overlooked.

One major issue with 125 grain magnums is that the bullet's relatively short length allows a brief span of time when the mouth of the cartridge is left open before enough of the bullet is in the forcing cone. This blast of ultra hot gas is a major contributor to both forcing cone stress cracking and to top strap flame cutting.

All-copper bullets (like the Barnes X) have to be longer than jacketed lead bullets of the same weight. As density goes down (switching from mostly lead to all copper), volume must increase to maintain the same weight. Since a bullet's diameter is essentially fixed by its caliber, the only dimension that can grow to increase volume is its length.

It is possible that this length increase would make the copper bullet long enough to have its base still in the case while the first full-caliber portion of the bullet has entered the forcing cone. As this happens, combustion in the case may have subsided enough to bring flame temperatures down to a more reasonable level before the bse of the bullet leaves the case.

So it is very likely that solid copper hollow points used in 125 grain .357 Magnums will virtually eliminate the top strap cutting and forcing cone erosion issues that have been so common with this load in the past.

The all copper DPX bullet is longer than an equivilent weight lead bullet.

However, I'm not sure about this concept having anything to do with the flame cutting etc. If that were true, hot .38+p's would be an issue also because they are much shorter than .357's. In that case, there is a very long distance to cover before entering the barrel itself compared to magnum case based loads. This is much more distance than the distance difference between DPX's and leads.

Marvin, you're over thinking this. The flame cutting issue is worst with slow burning powders and light bullets at max loadings. The dpx, you can shoot with confidence. If you shoot a revolver at all, the top strap will have some cutting; however, it's a self limiting process.

Even the hottest 38 +P can't hold a candle in the pressure and temperature departments to the 125 grain .357 Magnum.

I am sure if you keep it clean and use factory ammo or your own careful reloads, you will find that gun will outlast you.

Patrick.

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John 3:16