Ok, I experimented. Now I need to take the next step.

[Black Jaque Janaviac]

I tried paper patching my .357 magnum, model '92 Rossi.

Using 125 grain pure lead and 13 to 13.6 grains of Blue Dot I got little to no leading, but little to no accuracy.  Chronograph read 2000 to 2070 fps. :shock:  (Oh, I crimped these ones)

Groups were the size of paper plates at 40 yards.  I tried dropping down to 12 grains of Blue Dot and couldn't put a hole in a plate at 40 yds.

Next I tried 158 grain pure lead bullet and 13 grains of Lil' Gun (No crimp this time - just loaded single shot).  2 3/4" group at 40 yards.  I ran out of patched loads so I didn't chronograph those.  However, I did chronograph a wheel-weight alloy bullet (no patch) with the same powder charge at 1680 fps.

I don't have much as far as special tools and equipment.  I just used my regular bullets, patched 'em, then ran 'em through the sizing die after the paper dried.  This works pretty well using a pure lead RNFP.  With the flat point I just run 'em through the sizer (Lee) upside down, or "tail-first".  Most of 'em survive the experience.

Now, I'm wondering what to try next.  More powder?  Less powder?  Different paper - I just used some 0.0025" packing paper that came in a box from Mid-South Shooter's Supply.

How about using a .36 felt wad over the powder?

What should the spent patches look like?  All I find is tattered shreds of paper.  Should I look for anything?

[Castaway]

I'd try a slower powder so I could get more of the case filled.  Seems I do best with a 100% lload density.

[alan in ga]

more powder. Sometimes a load needs to have GOOD quick burning load to come as close to "bumping up" to diameter like black powder does. Smokeless powders have a slower ignition pressure pulse > and a quick 'pulse' is supposed to get paper patched bullets started in bore before powder can blow around the bullet which will blow patch off and erode bullet sides.
Cotton content in PP paper is supposed to give it strength to help protect bullet in firing procedure.
Also,,,CRIMPING is supposed to be a death knell to PP bullets. Crimp trys to pull/scrape paper jacket off.
Try seating bullets out to where they seat into throat/rifling leade in bore.
Fun, huh?
I think the PPB fan's headache is when you have a bullet for some reason loose it's paper jacket and lead all the way down the bore!! Then you have a real cleanup job before you can shoot another PP bullet or the lead from previous bullet will upset any next PP bullet's jacket.
I like to shoot hard lead cast bullets very slow > easy way to remove lead from a 'bad shot'.
alan in ga.

[tommy4toes]

figger out yer bore diameter ( not groove ) and then patch to .002 above that number. Depending on your throat type you may need to adjust your powder charge to allow chambering. When you use smokeless powder, the bullets wont bump up like they do with black. Also, are you using wads, or grease cookies? They can affect accuracy big-time.

t4t

[Black Jaque Janaviac]

WOW!

I think increasing the powder dose was the best advice I got.  It was amazing.

Normally for my cast bullets a 13 grain charge of Lil' Gun works really well.  But, it didn't work very well at all with a paper patched bullet.

So I loaded a box of incrementally increasing doses of Lil' Gun and hit the range.

The first two loads tattered the patches like usual, spewed bullets all over like a scattergun, and leaded the bore something ferocious.

The third one was the charm.  At 16.2 grains of Lil' Gun the patches started unravelling in large pieces.  And the groups immediately shrunk.  No leading.  I shot a few over the chronograph and it read an average ~1900 fps!  Pretty dang good for a .357 Mag, 158 grain pure lead bullet.  Yep, that's .357 magnum, not maximum.

16.9 grains of Lil' Gun did about the same, with no appreciable velocity increase.

A couple other things I changed:  I switch to 25% cotton velum.  That's some pretty strong stuff.  I also use magnum primers to help give an extra sharp boost.  But it was the stronger dose of powder that really did it.  Incidentally 16.2 grains is getting close to 100% load density.

Hodgdon allows as high as 18 grains of Lil' Gun for a 158 grain jacketed bullet.  So maybe I'll see if there's anything worthwhile when I approach that.  Incidentally, what do you use for a max charge when pp'ing with smokeless?  Do you use the "lead bullet" max or the jacketed bullet data?

T4T,
No wads, no grease cookies.  I'm using smokeless powder.  I don't "patch up" to diameter, my bullets already exceed bore diameter.  They are the same bullets I use "as cast".  I just run the patched bullet (way oversized) through a .358" sizing die.  That squishes the paper and bullet down to size.  I love the idea because it is working and I didn't have to buy anything extra except the velum paper.