Paper patching RBs?

[Jim]

I got to thinking(I knew I smelled something burning) about casting and loading some .690 RBs for one of my 12 gauges. The barrel on the shotgun I plan to load for is 24" and .720 cylinder bore all the way through.
What would be the pros and cons of paper patching a .690 RB out to oh, say, .725 or so?
I'm thinking a plastic gas check disc, appropriate number of 1/4" fiber wads, A P/P RB and a roll crimp to close the shell. Am I close or am I about to blow the barrel off my shotgun?

[Kskybroom]

Now I smell something burning...
What if you patch the ball to fit inside a shot cup?

[Bloodman14]

If you patch to .725, would it even go into the shell? Would the shell chamber? I think I'd do a 'dummy' shell or two.

[longbow]

First, 0.720" bore sounds tight for 12 ga. Nominal bore size for 12 ga. is 0.729" and most or at least many rifled barrels run a little smaller at 0.727" groove diameter.

Not saying it isn't so, it just sounds tight.

Having said that, I regularly shoot 0.735" balls from my 0.729" bore smoothbore with no problems. I have also shot those same loads through a friend's rifled Remington 870 with 0.727" groove with good results. The 0.690" ball should be just fine in your 0.720" bore if patched to snug push fit.

I have also tried paper patching (more like a paper shotcup) 0.690" balls for my gun. It worked but accuracy was not great. I suspect the ball and "patch" rolled a bit entering the forcing cone or tore opening the roll crimp (fold crimp might be better).

As long as you are using pressure tested round ball or slug data, or shot loads for the same weight as the ball you should be fine. BPI and Lyman have loads listed for 0.690" balls.

0.690" balls fit into shotcups with THIN petals ~ at least for 0.729" bore. If your bore is 0.720" I doubt you will find a suitable shotcup. I have tried them in Winchester AA Red and Pacific Versalite shotcups which are both a tight fit in my bore and the petals shear or wrinkle.

Mylar or Teflon wrap may work as they are thin. One or two wraps might be easier than paper patching.

What might be an easier and better approach is to use donut wads or inverted plastic gas seals under the balls.

I don't have a photo handy but look at AJ's photo here:

http://castboolits.gunloads.com/showthread.php?t=78620

On the far right is a brush wad with basically double ended gas seal. There are some cup shaped gas seals that can be cut off and inverted under the ball to center it. Some pick up used wads from a trap range, cut the gas seal off and use that under the ball.

Also, use a solid wad column. I find that if I do not used a good hard card wad column or nitro card wads under the ball the plastic shotcup or gas seal deforms around the ball leaking gas and ruining accuracy.

So, the short story is that yes it should work, no you won't blow your gun up if the ball and patch can be pushed through the bore and choke (if there is one) and best of all, you should be able to get good accuracy to at least 50 yards. I often get 3" to 4" groups at 50 yards.

Longbow

[tommygirlMT]

I hope the first two responses above me were jokes not real posts.

The internal diameter of most 12ga. shot wads runs at about 0.680" --- how are you going to patch a 0.690" RB to fit that --- its slightly too big to start with.

Normal 12ga. slug gun bore diameter is 0.727" to 0.730" and full bore diameter slugs such as loaded by Dixie commercially and people like Greg and me as reloaders are usually sized at 0.729" to 0.731" diameter --- they fit inside the hulls just fine --- therefor a ball patched up to0.725" should fit just fine because its slightly smaller then what we are loading without any problems.

Sorry if all this sounds abrasive but uninformed responses to a valid question --- well they push my buttons --- I do smell something burning all right but its not the OP I smell.

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As to the original question feilded by the OP my response would be that the only problem I see with what you are considering doing is that it excessivly thick multi-layer lots of wraps around the bullet paper patching has not given me the best results with my own paper patching work with rifle catridges --- you might be better of patching up a 715 ball from the Lyman mold and using less wraps of paper.

If you already have the 690 ball mold though --- no reason not to try it and see.

[tommygirlMT]

Long-bow you posted while I was typing --- I'm not talking about you I'm talking about the two posts before yours.