FWIW the 503 crimped in the groove doesn't seat as deeply as the 429421 that I have (an Arsenal mold clone). If anything the 503 should have less pressure despite being a few grains heavier. One thing that is weird the 429421 is said to weigh 250 or 255 grains. With 96-2-2 alloy that I like it usually weighs just under 260 while the 503 weighs around 262-264 with the same alloy. This is after lubing. I guess the lyman spec weight is with #2 alloy or 16:1 or some other light alloy.
I think it is with Lyman #2. My Lyman 4 cavity throws COWW at 253gr. It is from the early 70s, has a round grease groove, and a full front band. I have fired it more than any other in .44 Mag and .44Spl.............
Thanks for the pressure work ups, Larry...you've confirmed my Quickload calculations. I'm an enthusiastic user of Skelton's old load for my .44's, both Spl and Mag...7.5 gr of Unique, getting 16,300 psi with RCBS 44-240 for 923 fps from a 5.5" bbl. or 874 from a 4.6" tube, or 964 from my 6.5" Smith M24...while 8.0 gr of Herco with the same bullet gives me 15,150 and 906 fps again using the 5.5" bbl. or 855 from a 4.6" tube. Either load has enough umph to put down a crippled horse here on our farm...a sad day for all concerned...
Both powders do give me great accuracy from 3 Flat Top Ruger .44 Spl's, and a Smith M24 with a 6.5" bbl. using that RCBS bullet, and does as well with Mihec's version of the 503 bullet. Wish I could get them to feed through my Marlin 336 Texan in .44 Magnum...but it's a single shot with any of the above. Same is true with my son's Marlin 1894 Cowboy .44.
Best regards to all, and thx again Larry. Rod
Last edited by Rodfac; 11-20-2020 at 09:28 AM.
Rod
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |