Jim: re Lee Postell bullet mold.
I only shot them through a NEF Single shot break action. They weren’t stable at any velocity. The twist rate wasn’t adequate to stabilize such a long projectile.
They were too long to allow them (besides too pointed) for my Marlin 1895 to cycle or fire.
I suggest that the rate of twist in your barrel might be a tad slow. Also, your sample size is too small affecting your perception of actual precision.
Shoot them some more at shorter distances to confirm your results.
Also, you may need to speed them up a bit.
Going transonic may affect stability.
Thanks, GooseGestapo. Yes, I see several potential issues on this Lee bullet, some of which I have now found mentioned in forum postings across a wide band of different "buffalo rifle" users:
- It is a very long bullet, which usually necessitates a short twist rate, like 1 in 16. My Pedersoli, and most other non-custom 45-70 rifles are 1 in 18.
- Despite its long overall length, it has a relatively short shank, with 3 large lube grooves in it. This makes it harder to align and stabilize while in the barrel.
- Its claimed BC is quite high, thanks to the spire shaped ogive, but that apparently also makes it less stable in wind and in its reaction to transonic disturbances.
- Despite its long length, it is, because of the narrow ogive, rather light for long range shooting. 500 to 530 grains would have been a better weight. But with that narrow ogive, the bullet would have to be made even longer to add weight, which woulf accentuate all 3 of the above items.
- The combination of its long length and its pointed tip make it a bullet not very usable in your Marlin or any other 45-70 lever action - even when loading single cartridges from the top. It CAN be done but it's not easy.
On the other hand, there is an online 8 minute video of a shooter shooting an almost identical 500g Lee bullet at a metal gong target set at 1000 yards range and several hundred feet higher than the shooter's elevation. And while he does only actually hit the gong a few times in 16 shots, ALL the missed shots are close - like within 1 to 2 minutes of the gong, despite winds that are fierce and rapidly changing:
Testing of, and addressing rumors regarding the of the Lee .45 Caliber "459-500-3R" 500 Grain Cast Bullet at 1,000 yards.
www.youtube.com
So, evidently, despite the adverse attributes, it CAN be mastered.
Like the Lyman 457125, it can be "challenging" and frustrating.
I spent the morning at the range today with several different loads using it. I'll post about my findings in a separate thread after I have analyzed and understood the target sheets and the Labradar logs. But I can tell you already tonight: I DID get it to group. Not nearly as well as I would like, but way better than my prior attempts.
Jim G