H-110 and the 357 / 38

longfellow · January 25, 2012, 09:48 AM

As most 357 (and Lyman 358429 casters) already know, this bullet is too long for many cylinders, my Old Model Blackhawk included. I would like to have a medium-heavy load unsing H-110 and this bullet but given that I need to either use Special cases or crimp over the front band (effectively getting you back to close to 38 Special case capacity when that same bullet is crimped in the crimp groove of a Special case), there is no publeshed loading data.
Does anyone have any experience with H-110 and this bullet under similar circumstances - either crimping over the shoulder or using Special cases? My sense is that you should NOT just follow 357 mag loading data if you crimp over the shoulder since case capacity is a significant variable impacting pressure.
Thanks,
Ed

SL1 · January 25, 2012, 10:58 AM

If it were me, I would measure the water capacity of my new .357 magnum brass, then do the math to figure out how much of that water capacity remains with (1) the bullet seated to the depth of whatever load data I have, and (2) the bullet seated to the depth I need to fit the cylinder. Subtracting those two capacity losses from the empty case volume gives (1)the powder space in load data, and (2) the powder space in the cartridges you inend to load. Adjusting the charge weight in the load data by the ratio of the powder spaces should give you a safe way to figure a max load for your COL.

But, remember that changing case brands, primer strength, etc. can make a substantial difference.

So, for example, if the data you have is shot in Winchester brass and you have Federal brass, you should probably get some Winchester brass to measure the internal water capacity, rather than just assume that it is the same as your Federal brass.

As for primers, most H-110 data should be for magnum primers. But, if you try the same technique with another powder, such as AA#9, be aware that Accurate has switched from shooting their data for the .357 with standard primers to shooting it with magnum primers (to protect the dopes who just ignore the data and use magnum primers for everything in the .357 because it is a "magnum"). Switching primer strengths can make as much or more difference than slighly changing COL, maybe as much as 11,000 psi.

SL1

longfellow · January 25, 2012, 02:32 PM

That's pretty good SL1.
It's analytical.
It's technical.
It requires precise measurements.
All stuff that engineers love.

Thank you very much.

PS I am using magnum primers with the H-110.

January 25, 2012, 09:48 AM	#1
longfellow Senior Member Join Date: October 11, 2010 Location: Upstate NY Posts: 144	H-110 and the 357 / 38 As most 357 (and Lyman 358429 casters) already know, this bullet is too long for many cylinders, my Old Model Blackhawk included. I would like to have a medium-heavy load unsing H-110 and this bullet but given that I need to either use Special cases or crimp over the front band (effectively getting you back to close to 38 Special case capacity when that same bullet is crimped in the crimp groove of a Special case), there is no publeshed loading data. Does anyone have any experience with H-110 and this bullet under similar circumstances - either crimping over the shoulder or using Special cases? My sense is that you should NOT just follow 357 mag loading data if you crimp over the shoulder since case capacity is a significant variable impacting pressure. Thanks, Ed

January 25, 2012, 10:58 AM	#2
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	If it were me, I would measure the water capacity of my new .357 magnum brass, then do the math to figure out how much of that water capacity remains with (1) the bullet seated to the depth of whatever load data I have, and (2) the bullet seated to the depth I need to fit the cylinder. Subtracting those two capacity losses from the empty case volume gives (1)the powder space in load data, and (2) the powder space in the cartridges you inend to load. Adjusting the charge weight in the load data by the ratio of the powder spaces should give you a safe way to figure a max load for your COL. But, remember that changing case brands, primer strength, etc. can make a substantial difference. So, for example, if the data you have is shot in Winchester brass and you have Federal brass, you should probably get some Winchester brass to measure the internal water capacity, rather than just assume that it is the same as your Federal brass. As for primers, most H-110 data should be for magnum primers. But, if you try the same technique with another powder, such as AA#9, be aware that Accurate has switched from shooting their data for the .357 with standard primers to shooting it with magnum primers (to protect the dopes who just ignore the data and use magnum primers for everything in the .357 because it is a "magnum"). Switching primer strengths can make as much or more difference than slighly changing COL, maybe as much as 11,000 psi. SL1

January 25, 2012, 02:32 PM	#3
longfellow Senior Member Join Date: October 11, 2010 Location: Upstate NY Posts: 144	That's pretty good SL1. It's analytical. It's technical. It requires precise measurements. All stuff that engineers love. Thank you very much. PS I am using magnum primers with the H-110.