can coated boolits be treated like paperpatched?

[Black Jaque Janaviac]

I am curious if one of the advantages of powder coating is being able to run softer boolits at higher velocities. Are pure Pb coated boolits good for up to 2000fps as they would be paperpatching them? Or are the coatings just another form of lube?

[Bama]

I am curious if one of the advantages of powder coating is being able to run softer boolits at higher velocities. Are pure Pb coated boolits good for up to 2000fps as they would be paperpatching them? Or are the coatings just another form of lube?

I will probably open a can of worms but the simple answer is yes and no! If your alloy is strong enough to hold together at that RPM and the bore condition and fit of your gun, no problem. If it is not, PC may help a little but it is not a magic bullet. Best thing is to try it. It has worked really well for me.

[Black Jaque Janaviac]

Ugh. Well any day at the range is a good day, so yay for that. But some days just don't go as you might have envisioned.

I took my .357 Model '92 lever action out with some 125 grain Lee RNFPs coated with VHT epoxy paint. Loaded 10 each with 19.8 gr, 20.3 gr, and 21.0 gr of Alliant 300-MP (max is 22.3 gr). I intended to chronograph them to see what they would do. I started getting error readings. Then I finally noticed the low battery message! Grrr.

Well I got some of them to work. At 19.8 grain of 300-MP the boolits were whistling along at between 1948 (low) and 2116 (high). The primers were rounded and the outside of the cases were sooty, I believe that indicates low pressures (and likely the cause of the 168 fps spread). I shot 5 of the 20.3 grain loads and got exactly ONE reading; 2182. I then shot 5 of the 21.0 grain loads and got zero readings.

Groups at 25 yards were not stellar and got progressively worse as I went up the ladder. However at no point did I see signs of excess pressure. After everything I ran a cleaning jag with a patch on it and got terrible leading! Alas, I do not know when the leading began. Or if it began at the start.

My alloy is just plain ol' wheel weights. Not heat treated or quenched. I applied two coats of VHT epoxy by spraying them, then baked at 300°.

So. . . where to go from here?
A) get new battery for chronograph - for sure.
B) test to see which loads caused the leading?
C) if leading was present from start, scrap this powder-boolit combo?
D) try same powder with 158 grain RNFPs? Maybe lower velocities will get less leading?
E) try Harbor Freight powder coating with same 125 grain boolits?
F) go UP the powder charge ladder? Sometimes too little pressure doesn't obturate boolit enough.

[popper]

So far my results say NO. Depends on burn rate and pressure. Paper has a fibrous content that gives it strength, PC doesn't. I can get to ~1500 PB PC ACWW before accuracy goes to pot. (H110 in BO). 4227 doesn't seem much better. 2400 in the MG 30/30 does OK.

[Black Jaque Janaviac]

Popper,

Is that 1500 fps from a pistol or rifle? I often see velocities listed, but people seem to discount whether those velocities were achieved in a 6-inch barrel or a 24-inch barrel. I believe there can be a big difference in the amount of stress a boolit is exposed to while accelerating to a given speed but over a longer bore.

I got most of your abbreviations, but I'm not sure what BO or MG are.

[popper]

Rifle - 18" 300BO carbine 1:10. The MG is a marlin 30/30.

[Black Jaque Janaviac]

So what is the limiting factor do you suppose? I know that the paper patchers all figure that pure lead or lead-tin alloys are good up to standard .30-30 velocities, or 2400 fps. After that I understand that the air resistance or the rotational forces rip the softer boolits apart.

As far as rotational forces - you can get enough spin to tear up a soft lead boolit at just about any velocity - theoretically. So do you think the 1-10" twist in the BO is what's doing it?

Or - as I mentioned before - the force of acceleration can wreak havoc on a boolit. So the powder burn-rate necessary to get beyond 1500 fps in the 18" BO barrel (and the itty-bitty BO case capacity) means the g-forces during acceleration are higher than what the .30-30 does to a boolit over the course of the 20 or 24 inch barrel to get it up to 2400 fps.

[popper]

With proper (heat treated ) alloy & PC I've gone to 2700 from 24" 308W AR. Close to MOA @ 200 from the carbine. BO does fine with hard alloy @ 2100 fps, AC just doesn't cut it. Got to try some 4227 under the AC alloy to see if that works.

[Bama]

the Lyman 358156 works well in a lever gun at those velocities and a little higher BUT the gun will kick, sometimes at levels that are not conductive to top level accuracy. I use Smokes powder and shake and bake with ZERO leading. you MAY WANT TO GIVE IT A TRY. The guns are fun and reliable and surprisingly accurate out to 100 yd.

[popper]

People just don't understand how tough paper is. Take your grocery receipt, end in each hand and try to snap it apart. Then try a (reconstituted paper) tissue - easy right? Plus the paper twist on the base cushions the pressure some.
you can get enough spin to tear up a soft lead boolit Actually IMHO the boolit tumbles and can't take the stress, not just spins too fast that the alloy can't take it. Like a plane in a 20g turn - wings come off.
I have a 10" 1:8 BO pistol, ammo works just as good but I've never chronyd it.

[Black Jaque Janaviac]

Actually IMHO the boolit tumbles and can't take the stress, not just spins too fast that the alloy can't take it. Like a plane in a 20g turn - wings come off.

Well we know that there is nothing particular about 1500 fps that would tear up a boolit. My muzzleloaders shoot pure lead at 2000+ fps without a problem. So if there is something happening with your BO at velocities above 1500 fps it has to be happening inside the bore, or else the rifling pitch is spinning it apart.

I know that paper is strong, and makes an exceptionally strong boolit jacket. That is why I asked the question in the OP. People will take a pure lead boolit, wrap it in paper and race it up to 2200-2400 fps with regularity. You just can't do that with a conventionally lubed cast boolit without getting into harder alloys and gas checks.

I shoot .357 leverguns and they can be right at that performance level for paper patching. A 125 grain boolit with H110 can get going at 2300 fps from a .357 and a 20+ inch tube. The Rossi's have a notoriously slow rifling pitch which makes it even better for such loading.

However the tedious work involved with paper patching each individual bullet is not very appealing. If you could get a pure lead (or even just 11 bhn wheel-weights) going near 2000 fps by using PC that would be awesome.