Why powder coating my .45-70 cast bullets might not ever make precise long distance ammunition
- Thread starter JimGnitecki
- Start date
JimGnitecki
Member
It's not just the trajectory. It's keeping the bullet supersonic too. IF I can keep the bullet supersonic, I can practice using my Shotmarker electronic target system. It needs a bullet to be supersonic in order to detect it. IF I can keep the bullets supersonic out to 400 yards, I can practice better because I can get super-detailed data from each 5-shot group captured by the Shotmarker, withOUT having to walk 800 yards every time I shoot a target, to patch it and measure group MOA, etc. The system allows me to capture both a screenshot of each group AND a detailed csv file.
The BC for the bulelt i am testing is .342, which for a moderate weight .458 caliber bullet is pretty damn good.
As for recoil, I WAS shooting 475 to 500g bullets at 1400 fps. That's a power factor of 700. Witht he 350g plated bullet at 1750 fps (measured on the Labradar today), the power factor is 613. That means 12.5% LESS recoil.
I'd love to make the home-cast powder coated bullets work, but after several months of trying, and doing the outdoor casting now in Canadian wintertime weather (VERY cold most days), it gets old, and I don't see the potential for improvement of the magnitude that I want.
Jim G
RBHarter
West Central AR
I know a fairly persnickety gunsmith that went to some bizarre extremes to make a particular 45-70 1896 Win shoot little bitty groups. It was done in about 5 barrel configurations with the factory barrel then a Shilen . He fired something like 3000 rounds over a year finally giving up and admitting that at least that action regardless of free float , barrel loading , dovetail or floating bands it just wasn't going to shoot 10 into less than 3" .
Rules for long range success.
Have a rifle up to the task .
Take ammo prep to extremes .
Remove as many variables as possible.
Remove more variables.
Trigger time .
Better rifle/sights/trigger .
Trigger time.
Remove more variables.
I tell guys that ask "why doesn't the finished ammo fit in the comparator die ?" you've added another reamer to a set of tools that already has 2 chamber reamers and 2-3 die reamers to the process. That is exactly what you're doing by coating the bullet.
If you want to go fast and flat that's fine . I've pushed a 222 Rem in a 340 Savage 2600 fps greased and checked . With a 62 gr bullet that's the middle of the jacket load window. It's a 50 kpsi load with a jacket. It also shot 5 into a 1" grid at 100 yd .
I've pushed a Rapine 458-201 .459-255 RF plain base 2000 fps out of 45-70 1895G . Thats unpleasant to shoot but I made 2000 fps MV and that was the goal . The fact that it made 5 hits on a 50yd 4" plate was just gravy. Darrs lube period .
I've looked back on my shooting. The more I look at it the more I realize that I expect and awful lot from me and the loads . I'm also just really driven to do things in the least complicated possible way .
Just for a last perspective , grab your Lyman manual, flip it open to the 458 WM 405 gr Win SP mak a note of the start load speeds . Now flip it open to the 45-90, 100 ,110 ,and 120 data for the 405 gr Win SP. At TD levels the 45-90 in a 34" barrel maxes out really close . The 110&120 are right there in the numbers . The real difference is 20kpsi and 10" of barrel . I would imagine a 14# buffalo rifle would be somewhat more comfortable than a 9# 98 Mauser .
The point being you have a finite limit of what the action will handle , granted if it's a European proofed rifle it's good for a steady diet of 32kpsi CIP standard ammo . Pick the right powder, walk the edge with a Postell , Money ,or one of the pointy 535-550 gr bullets you might see 1800 fps . I can assure you fun to shoot won't be on the list of load attributes.
Rules for long range success.
Have a rifle up to the task .
Take ammo prep to extremes .
Remove as many variables as possible.
Remove more variables.
Trigger time .
Better rifle/sights/trigger .
Trigger time.
Remove more variables.
I tell guys that ask "why doesn't the finished ammo fit in the comparator die ?" you've added another reamer to a set of tools that already has 2 chamber reamers and 2-3 die reamers to the process. That is exactly what you're doing by coating the bullet.
If you want to go fast and flat that's fine . I've pushed a 222 Rem in a 340 Savage 2600 fps greased and checked . With a 62 gr bullet that's the middle of the jacket load window. It's a 50 kpsi load with a jacket. It also shot 5 into a 1" grid at 100 yd .
I've pushed a Rapine 458-201 .459-255 RF plain base 2000 fps out of 45-70 1895G . Thats unpleasant to shoot but I made 2000 fps MV and that was the goal . The fact that it made 5 hits on a 50yd 4" plate was just gravy. Darrs lube period .
I've looked back on my shooting. The more I look at it the more I realize that I expect and awful lot from me and the loads . I'm also just really driven to do things in the least complicated possible way .
Just for a last perspective , grab your Lyman manual, flip it open to the 458 WM 405 gr Win SP mak a note of the start load speeds . Now flip it open to the 45-90, 100 ,110 ,and 120 data for the 405 gr Win SP. At TD levels the 45-90 in a 34" barrel maxes out really close . The 110&120 are right there in the numbers . The real difference is 20kpsi and 10" of barrel . I would imagine a 14# buffalo rifle would be somewhat more comfortable than a 9# 98 Mauser .
The point being you have a finite limit of what the action will handle , granted if it's a European proofed rifle it's good for a steady diet of 32kpsi CIP standard ammo . Pick the right powder, walk the edge with a Postell , Money ,or one of the pointy 535-550 gr bullets you might see 1800 fps . I can assure you fun to shoot won't be on the list of load attributes.
OK, the need for supersonic to use the Shotmaker makes sense.
I would be spending a bunch of time with ballistics software to see what happens with a different BC and what velocity is required to stay supersonic to 400. I think it will be difficult.
A quick run thru an online ballistics calculator shows that a .350 BC with a 400 gr bullet at 1800 fps will give 1155 fps at 400. Just about supersonic but weather conditions will impact that.
Just not sure it is realistic. Will likely require a bullet from Tom at Accurate using a gas check.
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JimGnitecki
Member
i was shooting that 350g plated bullet at 1750 fps today, and the recoil was lower than with the 485 to 500g cast bullets I had been shooting at 1400 fps, so I now know it IS possible to shoot a 45-70 at 1750 fps and not regret doing so! I had loaded only a small quantity of cartridges, and only at 3 powder levels, just to see if that bullet is worth spending some time and effort on. It turns out it is.
Jim G
JimGnitecki
Member
The458 350GR SPITZER FCP bullet I am testing, which was developed by Campro for use in the 458 SOCOM, has a BC of .342. The Labradar tracked it as doing 1750 fps our of the muzzle at a load level safe enough for a 28,000 psi rifle. The Hornady online ballistic calculator says that, at my 3000 ft elevation above seal level, it will still be supersonic at 425 yards (1132 fps), and might even make 450 yards since Hornady puts it at 1110 (just below the 1120 speed of sound) at 450 yards!
The 1750 was higher than I expected. The load table had said 1675 fps, BUT that was from a 24" barrel, and my Pedersoli has a 30" barrel.
I only fired very few test shots just to check basic feasibility, but the very first 5 shot group fired was 1.2 MOA, and a later group stacked the 5 shots vertically, but all touching each other in one vertical ragged hole, at 150 meters = 164 yards and ZERO windage error at ALL (All 5 shots were EXACTLY vertical). I had a lot of trouble loading the test rounds yesterday because our cold winter weather caused a resurgence of static electricity - I had to tap the loading funnel to get grains of powder off the walls of the funnel into the cartridge case. I'm guessing that some powder may have been sticking in the tubular portion belwo the actual funnel, where i could not see it. That could explain the vertical stringing on that group. I'm going to have to dig out my anti-cling sheets and my electronic antistatic machine, which I have only had to use very rarely.
I have not yet analyzed the Labradara data for SD and ES, but I watched the Labradar screen after each shot and saw pretty consistent velocities.
This first rough test with this bullet has been encouraging.
And, the barrel was VERY clean after the range session. Maybe a bit cleaner even than it was after firing the cast powder coated bullets.
Jim G
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JimGnitecki
Member
See:
www.artfulbullet.com
for the direction I will try next, hoping for better accuracy results.
Jim G
Early testing: Might replace my hand cast powder coated 500g bullets for my Pedersoli with 350g plated swaged Spitzer
I have been posting about my Pedersoli Sharps replica .45-70 rifle’s accuracy which has hit a wall, despite repeated improvement efforts with 500g class bullets when fired at my 150 meters = 164 yards testing distance. The 150 meter testing range is NOT my ultimate planned target range. I want...
www.artfulbullet.com
for the direction I will try next, hoping for better accuracy results.
Jim G