1903 30-06 1000yds what mold!

[FAsmus]

Hollow-Point;

You might consider asking some of this membership to assist you in the testing phase of your very interesting project ~

Good evening,
Forrest

[frnkeore]

My competitors and myself, deal with trans sonic, all the time. We shoot 200 yards at + - 1400 fps. What happens to a trans sonic bullet at that range is that it tips, like the twist is to slow. What happens in LR shooting is that tipping causes a big drop in the BC until it re-stablizes causing additional wind drift.

I have seen some very good scores shot as the bullet goes through the target in this range so, it's does not necessarily cause inaccuracy.

Frank

As support for my postion that tipped bullets can still have accuracy, I offer this target, shot in a shoulder to shoulder match at 200 yards, in Modesto, CA last weekend.

Barry Darr had his Oehler Model 43 set up for me and others to test our loads @ 100 yards. My results were.

Altitude 89 Feet

Temp. 78F

Baro Pressure 29.99

BC G1 .375

Corrected muzzle velocity 1426

ES 10 fps, SD 3 fps

100 yard measured velocity 1278

predected 200 yard velocity 1154

Group .9, SD Radius, .3

While Barry did the testing at 100, the score match is 10 shots at 200 yards. The 6 center shots measure 1.050 or almost exactly 1/2 minute of angle, while the remaining 4 shots in the 24 ring measure 2.620 or 1.25 min. as you can see, about 7 of the 10 shots were tipped pretty badly.

Frank

[FAsmus]

Frank:

I have done some shooting in 40/65 that was intended to explore this stability question as it relates to accuracy.

The rifle had a 1:18 twist barrel and at the velocities I was restricted to (plain base bullets @ your favorite speed of 1350 - 1400) I was unable to stabilize the typical things like the RCBS 40-420-BPC or the SAECO 65740. These would print out-of-round but would generally shoot fairly well anyway.

My problem was that the poor stability was always on my mind even as I squeezed the trigger for each shot! I searched for a better solution for a long time, trying various weights and mold designs, always trying for the heaviest bullet that would stabilize in my barrel @ 1400 ft/sec - going the custom mold route and some expense as well.

I finally settled on a custom PB-350 gr with a nearly spitzer ogive. The bullet was as long as the SAECO 65740 but the shape seemed to improve its stability at the velocity level I was working in. This called the usual calculations for stability/velocity, bullet length and barrel twist into question!

I essentially tossed the calculations, went with my experimental results, loaded them up and went shooting..

Since then I took the 40 caliber barrel off the Ballard and hung it on my Marlin M1895 instead of the 45/70 barrel it came with. This was an excellent hunting outfit with Lyman 412263.

Later, I began loading the Marlin with SAECO 65640 and used the rifle to compete at Quigley in "Lever" class, which worked out well for a few years. (single-load only - the loaded cartridge being way too long for magazine function).

These days I've been shooting a 7x57. This rifle would stabilize SAECO 071 beautifully - and shoot nice tight groups - but I wanted a heavier bullet for the long range shooting I enjoy. I went with the RCBS 7mm-168-SP.

The 7mm RCBS would not stabilize well unless I pushed it to 2000 ft/sec. Fortunately this load has proven to be accurate and very consistent too.

Good shooting,
Forrest

PS - Shooting is 90% mental ~ the other half is physical. ~ Thanks Yogi..

[frnkeore]

Forrest,
The most likely reason that that your spitzer stabilized better that the other bullet bullet of the same lenght is that the CG was a little farther back.

Frank

[felix]

Forrest, remember the air resistance rule we have always talked about here: The more air friction (forwards and sideways), the boolit enjoys more twist to compensate. Therefore, a pointed boolit with the same length as a blunt one will require LESS twist for the same accomplishment. For the same reason, a lead boolit with a lead jacket instead of a copper one will require LESS twist. Rotational inertia, don'tcha' know! ... felix

[FAsmus]

Felix;

Ah! There you are again!

~ I'm sure you're right about that custom 40 caliber pill and the RCBS that followed it when I went to 40/65 on the M1895.

The 40/65 was originally on a Red Willow Ballard, from when they were up in the Bitteroots in Montana. It had a very strange throat, being about 0.140 long @ 0.414 right ahead of the chamber. The custom bullet cast at 0.415 and filled things up nicely, making the rifle shoot quite well once I'd figured it all out - which involved opening up the loading dies and the lubrisizer die for the non-standard diameter.

Good morning,
Forrest