Copper Washed bullets and crimp

S

Scribe

New member
- [ ] Crimp.

Hi Chaps,

I am hand loading for a 16 inch barrelled Rossi 92 in .44 Magnum. This is purely for target shooting. I have worked up pretty good load for 200 and 240 grain lead bullets. These are round nose flat points, .430 in diameter at velocities of 1000 to 1100 fps. These give me a 5 inch group at 50 yards. I am happy with this, so far, because the sights are Rossi out of the box and my eyesight, even with varifocal glasses, is still 58 years old.
Purely for the fun of it, I have loaded some magnum loads. 240 grain truncated cone FMJ, 215 and 255 grain gas checked lead semi wadcutter and 240 grain copper washed round nose. All are going at around 1500/1600 FPS The first two are ok, but the copper wash are all over the place. 10 inch groups. All rounds stabilise, no key holing. Previously I asked this forum for advice on 300 grain bullets that were key holing and the general advice to up the velocity from Special to Magnum levels worked well.
I put minimal crimp on the case mouth. Just enough to secure the bullet. Could this effect the copper wash accuracy.
 
I can't speak to the accuracy issue, but I have pushed copper plated bullets in my Henry .41 Mag up to 1400 fps. I didn't notice any huge loss of accuracy but the copper build up was pretty substantial and happened in about 30 rounds. I don't push them past 1200 fps anymore and all is fine. It took a lot of work to get the copper out, but it has stayed clean ever since and keeping it under 3" at 50yds with open sights is not hard.
 
A couple thoughts; My Puma in 44 Magnum won't reliably feed SWC in Magnum brass. With some fiddling and using 44 Special brass 240-250 gr SWC will feed fairly well. The plated bullet w/o crimp groove/cannalure should probably be crimped with a taper crimp and I wouldn't use them in my levergun. With even "light" loads recoil and magazine spring tension requires a good crimp to keep the bullets in place. And my experience with plated bullets, a taper crimp isn't quite enough...

I tried about 1,000 plated bullets, mostly in 9mm and 45 ACP, but did try a few in 38 Special and 357 Magnum. In the semi-autos they were just OK, but a fail in the revolvers, too much bullet "walking" from recoil...
 
Maybe you're just pushing them too hard.
Copper washed? Plated?
What brand/type of bullet?
I put a medium profile (roll) crimp on my plated bullets, just to the point where I can see the bullet is slightly indented at the case mouth. Recovered bullets show a crease in the plating where the crimp was, but no exposed lead or any peeling.
Keeping case mouth flare/expansion to a minimum reduces the need for a more aggressive crimp.
I've always had best luck with plated bullets at around 900-1100 fps.
Sometimes rifling can cut the plating. My revolver's rifling will slice the heck out of one brand of .357 125 grain flat point, but shoots the same brand's .357 158 flat point just fine with no slicing and far better accuracy.
I guess my point is plated bullets are moody, good luck.
 
A copper washed round nose is still just a cast bullet. What's the load?
Around 1500/1600 FPS is decidedly vague. However, it's also too fast for .44 Mag cast bullets. Hodgdon's site .44 Mag Rifle shows max loads for a cast 240 running 1437 FPS with 11.0 of HP38.
 
We guarantee our Standard Pistol Bullets to handle velocities up to 1,250 fps,
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https://www.berrysmfg.com/faq#FAQ11

Any velocities over 1200 FPS we recommend either our Heavy Plate Concave Base or Hollow Point products for superior accuracy.
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https://www.xtremebullets.com/Bullet-Load-Info-s/1952.htm

In general, our bullets typically perform their best when shot at velocities no greater than 1,200 to 1,250 Feet per second (FPS).
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https://www.rainierballistics.com/reference/faqs/

Try a better bullet that won’t come apart at 1600fps and see if that makes your groups shrink.
 
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