The Firing Line Forums - View Single Post - New handloader article on "guessing pressures"

Peter M. Eick · September 12, 2002, 05:18 PM

Guy,

The 38 special load I was using in a 6" python:
Starline brass trimmed to 1.140, 2nd firing, LaserCast 158 grn SWC, cci500 primers, 4.0 grns 231, 1.462COL. My 35p gave me the following on 20 shot strings: 845+, 805-, 40s, 821m, 11sd.

Same load with 4.3 grns 231, 897+, 851-, 46s, 872m, 11sd for 20 shots.

I rounded a bit on my prior posts and mixed the info from my 4.0 and 4.3 loads. I will endevor to be more precise in the future.

On the question of pressure rings. Please do a search because others have described it much better then I. In a nutshell it is a pressure detection method based upon the case expansion as measured across the rim, body and taper of the case depending upon which school you use. These measurements are all calibrated to factory expansion in your gun, so you are working by comparison. This is a brutally short description of a sophisticated technique. Please read up on it in the search pages or in the Speer/Seirra manuals.

Thanks for the other comments. I thought it was very interesting article. It is one to re-read a few times.

September 12, 2002, 05:18 PM	#11
Peter M. Eick Senior Member Join Date: August 3, 1999 Location: Houston, Texas Posts: 2,991	Guy, The 38 special load I was using in a 6" python: Starline brass trimmed to 1.140, 2nd firing, LaserCast 158 grn SWC, cci500 primers, 4.0 grns 231, 1.462COL. My 35p gave me the following on 20 shot strings: 845+, 805-, 40s, 821m, 11sd. Same load with 4.3 grns 231, 897+, 851-, 46s, 872m, 11sd for 20 shots. I rounded a bit on my prior posts and mixed the info from my 4.0 and 4.3 loads. I will endevor to be more precise in the future. On the question of pressure rings. Please do a search because others have described it much better then I. In a nutshell it is a pressure detection method based upon the case expansion as measured across the rim, body and taper of the case depending upon which school you use. These measurements are all calibrated to factory expansion in your gun, so you are working by comparison. This is a brutally short description of a sophisticated technique. Please read up on it in the search pages or in the Speer/Seirra manuals. Thanks for the other comments. I thought it was very interesting article. It is one to re-read a few times. __________________ 10mm and 357sig, the best things to come along since the 38 super!