Am I correct in that barrel length doesn’t effect pressure. Velocity should increase but not necessarily pressure.is this correct? Thanks Bob
Am I correct in that barrel length doesn’t effect pressure. Velocity should increase but not necessarily pressure.is this correct? Thanks Bob
OLD POST but still alive--My LEE mold dropped at .429 so I got a .436 <common>drill bit an removed the gas check and ordered a .432 sizer and it worked. I use 2400 on the low side also and does fine. I use a SRH but haven't tried them in my JM Marlin yet. I liked it so much I did the same to my 240 LEE pan lube mold.
Last edited by 45DUDE; 10-03-2024 at 06:49 PM.
again, for what is worth...310Lee: sized at .430, seated at the lower crimp groove, gas check, Lee alox lubed_ 19 grains of Vihtavuori N110, Fiocchi brass, Fiocchi Lp primer_MTMrest-tested on Burris scoped 9,5"SRH _
Heavy load with substantial recoil but without sign of overpressure, extremely accurate load_
a joy to shoot it on SRH, but I wouldn't dare use this recipe in my 29s_
Food is overrated. A nice rifle is way more important.
Rob
That's correct. The pressure spikes at some point in or very close to the chamber and begins to go down before the bullet leaves the bore. The pressure from the expanding gas pushes the bullet, but it doesn't have to stay at peak pressure once the bullet is moving, and with the bullet moving, the pressure begins to drop.
Rifling twist rate affects pressure, with a faster twist causing higher pressure, all else being equal.
Velocity will increase with barrel length up until the barrel is so long that the expanding gas no longer can push the bullet, in which case it would begin to slow while still in the bore. That of course is dependent on the cartridge and powder used.
Last edited by Bazoo; 10-08-2024 at 10:50 AM.
Okay I have half a dozen 44 molds from 180 grain button to 330 grain SSK.
I’m looking for a heavy bullet that will function in my two carbines, a Browning B92 and a Rossi 16 inch R92, reliability and also in my 4” Smith 29.
I had been using the SSK J.D. Jones 330 grain bullet with a heavy dose of 2400 for 40 years. But it was 1.710 overall length. Won’t function in the carbines.
The LEE 310’s have two crimp grooves. Upper measurement is 1.700 and the lower is 1.600 which works great for function. The only loading for this LEE bullet at the long COL in the 4th edition of the Lyman cast bullet manual. I’m using H110 starting at 15 grains ended up at 17 grains. 1025 fps in the Smith and 1375 fps in the 20” Browning. I plan on stepping up to 18 grains but have not yet.
Now this is safe in my guns but you would need work up slowly using your own judgement.
The LEE bullet looks good, nice and wide nose, cast soft and powder coated. The LEE mold drops at .430 but my guns need a .432 diameter, so powder coated brings the diameter to just a touch over .432. Gas checks were installed before powder coating.
On the left is the 330 SSK seated beyond the front driving band. Next is the SSK seated in the crimp groove. Third from the left is the LEE 310 seated to the lower crimp groove. The right hand cartridge is the LEE 310 crimped in the upper crimp groove, 1.600 COL.
310’s checked and powder coated.
I'd also been loading the lee 310 over the published max for quite awhile. I went to give somebody load data, so I verified with a couple sources....and I was running quite hot. Never had any issues, and I've probably sent 1200 or more down range.
Still, I figured it was probably prudent to knock it down a bit and make sure I didn't get myself in any trouble down the road.
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 |