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Another .38/.357 case Q?
- Thread starter gns4me
- Start date
Too me the answer is no, if you seated the bullet to make them the same overall length you have more of the projectile gripping inside the case Of the 357 which would change pressure etc , etc
Flip slide aswell, If you seated the bullet farther out on the 38 special case to make it the same COL as a 357 there less grip on the bullet less pressure.
Flip slide aswell, If you seated the bullet farther out on the 38 special case to make it the same COL as a 357 there less grip on the bullet less pressure.
Onward Allusion
New member
No ^^^ what he said and there's also the difference of case thickness. I personally wouldn't load 357 charge in a 38 case.
No. You will have less bullet in the case, thus less neck tension. Also it will most likely not line up with the crimp groove or cannelure, making it hard to crimp further increasing the problem. Likely resulting in poor or incomplete powder burn and low or erratic velocity. The 38spl brass is also thinner in places. While in theory it should hold, It would probably be fairly hard on the brass.
some numbers;
.357 Magnum, max case length 1.290"
.38 Special max case length 1.155"
Difference = 0.135"
.357 max loaded length with bullet 1.590"
.38 Special max length with bullet 1.550"
difference = 0.040"
you can do the math, but it might help visualize things by laying out a .357 and .38 cases and bullets next to each other. case bases on the same line, bullets next to the case in the spot that gives you the overall length you want and see how much of the bullet would be in the case and what the apparent case powder space is.
.357 Magnum, max case length 1.290"
.38 Special max case length 1.155"
Difference = 0.135"
.357 max loaded length with bullet 1.590"
.38 Special max length with bullet 1.550"
difference = 0.040"
you can do the math, but it might help visualize things by laying out a .357 and .38 cases and bullets next to each other. case bases on the same line, bullets next to the case in the spot that gives you the overall length you want and see how much of the bullet would be in the case and what the apparent case powder space is.
This is the reason bullets with two crimp grooves exist; one for 38 Special and one for 357 Magnum. Same with double cannelure or double crimp groove bullet's for 44s for Special and Magnum. The Magnum cases are longer, but the maximum COL (needed for maximum powder capacity) is not as much longer as the cases are (indeed, with the 44 pairing, the Magnum COL is actually 0.005” shorter), so you need the two grooves if the same bullet is to make maximum COL with a roll crimp in both cartridges.
Yes there is an underlying Q? its a lack of available .357 brass and an abundance of .38 spec brass. I want to load RMR TC "happy face" bullets to test some powder. These have no cannular so it will roll crimped wherever i call COL That being the reason I thought that I may be able to adjust bullet out to match the COL of .357 mag round and use .38 brass Have enough bullet to seat in case and still make .357 COL. My thought is chamber will hold pressure as if I were using .357 Brass.
Last edited:
Jim Watson
New member
Skeeter Skelton loaded and promoted high velocity .38s with Lyman 358156 seated to the bottom crimp groove.
Are we talking about starting 357 charges or loads pushing the limits of 357?
I think any changes in neck tension due to the bullet sticking out further will mean the pressure is less using .38 Special cases. If .38 Special brass is thinner this also means the volume is larger and the pressure is lower.
If I were doing this I'd to stick to powders that do well in .38 Special and .357. Using powders that only work with higher pressure .357 loads might be inducing some of the issues mentioned.
I think any changes in neck tension due to the bullet sticking out further will mean the pressure is less using .38 Special cases. If .38 Special brass is thinner this also means the volume is larger and the pressure is lower.
If I were doing this I'd to stick to powders that do well in .38 Special and .357. Using powders that only work with higher pressure .357 loads might be inducing some of the issues mentioned.
jetinteriorguy
New member
I just have one question. Say this works, if you don’t have any available.357 brass to load anyway, why the big hurry to work up a load? I’d suggest just back ordering brass from Starline since it’s available for back order. You might get it faster than you think.
Starting to mid range loadsAre we talking about starting 357 charges or loads pushing the limits of 357?
I think any changes in neck tension due to the bullet sticking out further will mean the pressure is less using .38 Special cases. If .38 Special brass is thinner this also means the volume is larger and the pressure is lower.
If I were doing this I'd to stick to powders that do well in .38 Special and .357. Using powders that only work with higher pressure .357 loads might be inducing some of the issues mentioned.
Agreed but then again its knowledgeable experience at work. Like Keith and Skelton would use what they had..I just have one question. Say this works, if you don’t have any available.357 brass to load anyway, why the big hurry to work up a load? I’d suggest just back ordering brass from Starline since it’s available for back order. You might get it faster than you think.
its a lack of available .357 brass and an abundance of .38 spec brass.
Can you get .357 Mag ammunition?
if so, buy a couple boxes, shoot them, and there's your brass to use while you wait for backorders to be filled.
Both Lyman and NOE make bullet moulds that cast SWC's that has a gas check and two (2) crimp grooves ... a lower crimp groove and upper crimp groove .
Lyman # 358156 is 155 gr. and the NOE # 360-165-SWC GC is 165 grs.
Now the reason for the two crimp grooves ... when 357 magnum cases were so hard to find and 38 special were all over the range floor ... if you wanted to put a 357 load in a 38 special brass case you used the lower crimp groove ...it gave the same internal capacity as when using a 357 mag. case .
Now... If you have 357 magnum brass ... load it to 357 mag levels and seat to and crimp bullet in the upper crimp groove .... Pretty Cool Idea !
Skeeter Skelton used to do this ... as soon as I read his article I went right out and bought the Lyman mould and a box of gas checks ... that was 1971 and I don't think I have ever loaded that bullet in a 357 case ...they have all been in 38 special cases with 7.0 grs. Unique ... fired of course in 357 magnum revolver .
Gary
Lyman # 358156 is 155 gr. and the NOE # 360-165-SWC GC is 165 grs.
Now the reason for the two crimp grooves ... when 357 magnum cases were so hard to find and 38 special were all over the range floor ... if you wanted to put a 357 load in a 38 special brass case you used the lower crimp groove ...it gave the same internal capacity as when using a 357 mag. case .
Now... If you have 357 magnum brass ... load it to 357 mag levels and seat to and crimp bullet in the upper crimp groove .... Pretty Cool Idea !
Skeeter Skelton used to do this ... as soon as I read his article I went right out and bought the Lyman mould and a box of gas checks ... that was 1971 and I don't think I have ever loaded that bullet in a 357 case ...they have all been in 38 special cases with 7.0 grs. Unique ... fired of course in 357 magnum revolver .
Gary