Bullet gr. for .38/.357 K frames

[lhump1961]

OK...so my 66's and 19's are good with most any ammo up to 158gr .357. My understanding is that part of the issue with the lighter bullet and higher pressure magnum loads is that the gases can get around the lighter grains and in front of the bullet causing the forcing cone to wear faster. The larger 158gr bullet makes this jump to the forcing cone without allowing gases to escape in front. There are more issues at work here but my question concerns this physical behavior.

Assuming this is true...looking at .38 loads with the shorter brass doesn't the same thing occur and wouldn't that contribute to the same problem regardless of bullet weight? Can I safely shoot lighter weight bullets in the variety of .38 and .38+P ammo?

I know this K frame/ammo issue has been overplayed to some degree and I know my K's are not "weak". Just looking for some clarity on ammo performance.

 

[cjw3]

As far as I know or have heard the problem came from firing K frame .357's with the lighter bullets, particularly 110 and 125 grain. And, I would say, a lot of them at that.

The pressure and velocity from .38 Special +P's is far lower; I wouldn't expect them to have the same effect even with jacketed bullets of comparable weight.

Regardless, since I reload I prefer cast bullets of one type or the other for use in my 19-5 and essentially use it for moderate loads only. If I have a need for magnum performance from a .357 (almost never any more), I have a 686 for that. I may use jacketed bullets for that purpose, but more often I like a good hard cast bullet for that use as well.

 

[ContinentalOp]

OK...so my 66's and 19's are good with most any ammo up to 158gr .357. My understanding is that part of the issue with the lighter bullet and higher pressure magnum loads is that the gases can get around the lighter grains and in front of the bullet causing the forcing cone to wear faster. The larger 158gr bullet makes this jump to the forcing cone without allowing gases to escape in front. There are more issues at work here but my question concerns this physical behavior.

Assuming this is true...looking at .38 loads with the shorter brass doesn't the same thing occur and wouldn't that contribute to the same problem regardless of bullet weight? Can I safely shoot lighter weight bullets in the variety of .38 and .38+P ammo?

I know this K frame/ammo issue has been overplayed to some degree and I know my K's are not "weak". Just looking for some clarity on ammo performance.

IIRC, the problem wasn't so much weight, but bullet length and velocity. Normally the bullet seals the cylinder gap long enough for the pressure to drop, but the 125gr JHP was a short bullet at high velocity so the gap wasn't sealed as well, allowing the still-hot gases to contact the forcing cone, eroding it over time.

I believe the problem was only with the full-power loadings, i.e. 125gr JHP at 1450fps. If you can avoid using that weight/velocity combo, or at least shoot it infrequently, there shouldn't be any issues. I believe most of the currently available 110gr ammo only have a muzzle velocity of around 1250-1295fps, which would not put it in the "full-power" category. As was said, .38 Special loads shouldn't be a problem, even +P+ loads.

FYI, my favorite .357 Magnum load to shoot in my 3" 65 was WWB 110gr SJHP.

 

[Warren Sear]

...I know this K frame/ammo issue has been overplayed to some degree and I know my K's are not "weak". Just looking for some clarity on ammo performance.

The "K frame/ammo" issue is real. I know; I destroyed a nearly brand new model 19 using a listed load. The Model 19 is one of the the weakest 357 Magnums extant. That's not a slam, just a fact. Think of them as 38's that will handle an occasional cylinder full of 357's and you should be OK.

The 125 grain 357's have the worst reputation for splitting the forcing cone on Model 19's.

 

[snuf]

I've given up on the 125 and 158 grains and now use 140 grain in all my .38/.357's, both large and small frame.

 

[lougotzzz]

I shoot 158 gr hard cast in my 357's. I load very light. I consider my 357 loads big 38's.

Two loads I have been using lately have been

3.6 grains of titegroup under 158 gr SWC

3.6 gr of W231 under 158 gr SWC

The tite group a little more punch the W231 a little less.

Both accurate

 

[lhump1961]

IIRC, the problem wasn't so much weight, but bullet length and velocity. Normally the bullet seals the cylinder gap long enough for the pressure to drop, but the 125gr JHP was a short bullet at high velocity so the gap wasn't sealed as well, allowing the still-hot gases to contact the forcing cone, eroding it over time.

I believe the problem was only with the full-power loadings, i.e. 125gr JHP at 1450fps. If you can avoid using that weight/velocity combo, or at least shoot it infrequently, there shouldn't be any issues. I believe most of the currently available 110gr ammo only have a muzzle velocity of around 1250-1295fps, which would not put it in the "full-power" category. As was said, .38 Special loads shouldn't be a problem, even +P+ loads.

FYI, my favorite .357 Magnum load to shoot in my 3" 65 was WWB 110gr SJHP.

Ok, just so I am seeing it clearly...although the 38 and +P rounds are shorter due to brass size and may allow hot gases around the bullet to the forcing cone, the pressures aren't enough to cause the problems sometimes seen in lighter gr .357 loads. I actually prefer the 38 or +P in my snubs for recoil and I'm not sure that the shorter barrels allow for the advantage gained in say a 4 or 6 inch barrel in terms of velocity with the hotter loads. I also have a snub 686 but, again, is there any real advantage to the hotter loads in a 2 1/2" barrel?

Correct me if I'm wrong but it seems to me that all the hot loads do is make a big "bark" but not so much extra "bite" in the snubbies.

Thanks for the replies!