Make sure the screens/timers maintain correct spacing. Long time since i had a chrony. Any one remember the card board with the wire used as a sky screen.
Make sure the screens/timers maintain correct spacing. Long time since i had a chrony. Any one remember the card board with the wire used as a sky screen.
Something ain't right.
"Standard" velocities in 40 S&W/175-180 grain bullets with 4" barrels run about 950-975 FPS. I carry that bullet weight, and don't mess with any others. Most fixed-sight service-grade pistols in 40 S&W "assume" this load is being used (sighting, spring rates).
I've slugged A LOT of 40 S&W barrels, including several Sigmas. They are UNFAILINGLY .400" or .401", unlike the variance seen in 9mm throats and grooves. I'm glad that got cleared up.
I just mic'd the expander stem in my RCBS 40 S&W/10mm die set--.3965". The expander spud in the Lyman Multi-Charge expander die set is .3980". MUCH better for loading cast boolits of .400"-.401". I'm still not certain what your actual boolit diameters are, but you DO NOT need .403". Just the brass-working from the under-sized RCBS sizing die to the over-sized boolit will set up early brass failure, and likely deform your bullet as well. From .3965" to .403" is a HUGE jump. Most modern die sets--especially for autopistol calibers--"assume" jacketed bullet usage. Do a "tale of the tape" on your pistol's fired brass vs. its dimensions on sized brass--you'll likely get an eye-opener there, too.
Assuming your velocities are correct from the Chrony, you are overloading your ammunition. The early retirement of your brass and the "wiping" of headstamps is further evidence of same.
I don't paint bullets. I like Black Rifle Coffee. Sacred cows are always fair game. California is to the United States what Syria is to Russia and North Korea is to China/South Korea/Japan--a Hermit Kingdom detached from the real world and led by delusional maniacs, an economic and social basket case sustained by "foreign" aid so as to not lose military bases.
I just received a response from Ramshot/Accurate's ballistician after showing them Speer's response that "8.7 - 9.7 grains of AA #7 was a tested load with our 180 gr GDHP bullet".
"Alan,
We can only confirm our own data.
We test in SAAMI certified test barrels and 8.5 grains is definitely the maximum for a 180gr JHP whatever the make.
Regards
Johan Loubser
Ballistician
Ramshot/Accurate Powders"
Definitely a prime example of needing more than one reliable source of loading data to cross reference and ask questions if those sources differ from one another. I wonder how often this particular load contributed to kabooms in 40 S&W.
Wow. Lesson learned! Use only the load data published by the POWDER manufacturer, not a J-bullet manufacturer!
Lead is the new Gold!
Thanks for help in this matter Alan. I appreciate all the leg work. Now back to the original issue.....finally got some closure on the high pressure issues I thought I had with the cast and obviously "J" bullets , which was certainly justified No Thanks to Speer.
My "new " chrony was sending bad info, all FPS were approx 300 - 400 FPS faster than they were actually being sent down range. Double checked all my loads with a friends chrony right behind mine and all readings on mine were way high. His chrony was reading right at levels the bullets were supposed to be doing. Thanks all for the great help, learned alot about cast boolits thru this isssue and hopefully this will help others in the future. What a relief to finally find out it was not me , my boolits, or loading techniques.
Thorns though to Speer for sending me on a wild goose chase on overloading their bullets, compounding my problems when using their bullets to find out what was going on pressure wise when I thought it was my cast boolits.
US Govt mantra: If it's moving tax it. If it's still moving regulate it. If it stops moving subsidize it
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 |