Pump-action musket?

[Brick85]

I've been fantasizing about turning my 12 ga shotgun into a pump-action musket once in a while by loading full-bore round balls instead of slugs. But the biggest round-ball moulds I can find are .690, and the 12 ga bore is .792 as far as I know.

Has anyone tried this (surely someone here has!)? Or do folks just use .690's with a patch or wad or something?

[briang]

Lot's of guys do it with .69 balls in wads, there's quite a few threads about it.

[skiforce]

That is a hell of a 12ga @ .792. Try .735 or less unless you have an overbored barrel.

[Brick85]

That is a hell of a 12ga @ .792. Try .735 or less unless you have an overbored barrel.

Maybe it was .729 I was thinking. Thanks.

[longbow]

So far I have had best results with 2 sizes of round balls ~ 0.662" in a shotcup and 0.735" over hard card wads.

Generally getting groups of 4" to 6" at 50 yards. I think they can be improved and am working on it but I doubt consistent groups much under 4" will be achievable.

As a comment, I have not had any trouble using 0.735" RB in my 0.729" smoothbore ~ cylinder all the way NO CHOKE. But even using slow powder like Blue Dot I find the RB give more recoil and report than a heavier bore size slug over the same powder charge. I am using a published load for a 610 gr. full bore slug so not pushing the envelope.

If you go 0.735" I suggest powders in the slow burning range like Blue Dot or 4756 and there may be others. Also, I suggest dropping a few grains until you test the loads. I think the initial swaging causes a bit of a pressure spike.

I got my 0.735" RB mould from Track Of the Wolf.

I have not had very good success with 0.690" balls though others have. Lee makes a 0.690" ball as does Lyman.

Rapine (I think) makes a 0.678" double cavity. I find the 0.690" too big for shotcup and too small naked but the 0.678" should be about perfect in a shotcup.

Longbow

[missionary5155]

Greetings
And Dixie Gun Works still advertises RB at most any diameter up to 1.000.
Missionary

[NSP64]

I dropped a deer last season with a RB load out of my 20ga O/U. I got a 12ga this year and will try some RB loads.

[Silicon Wolverine]

"buck and ball" is another good "musket" combination as well.

SW

[mikenbarb]

A few loads use regular trap wads to take up the slack.

[Nobade]

I've been loading my 870 (cylinder bore cop barrel) with a .715 round ball, patched with ticking cloth, a WW AA hull, a stout charge of Blue Dot, and AA grey wads with the petals cut off. This combo shoots incredibly well, and should handle whatever needs shooting. On steel gongs and rocks there is no comparison to factory slugs. The round ball loads hit so much harder it's not funny. I got the idea from my Pedersoli 12 bore double rifle. If patched balls work in that, why not the 870? I tried some light target type loads first by cutting open the factory shells, pouring out the shot, cutting the petals off the shot cup, and seating a patched ball over it. Those worked well and didn't blow up, so I tried the Blue Dot loads, per the Alliant book. Works great, and with the cloth patch it's not going to lead the bore. I'm hooked, these are great fun and so much cheaper and more effective than factory ammo.

[Cheshire Dave]

I just got a Mossburg pump with a extra rifled slug barrel. Do you think the patched .715 round ball will work? I don't see a problem, anyone try this?
I was going to try a .690 in a shot cup but Longbow may have talked me out of that.

[longbow]

Cheshire Dave:

Just because it didn't work for me doesn't mean it won't work.

BPI lists recipes for 0.690" ball in shotcup as does Lyman.

Missionary5155 has had good success with 0.685" balls in shotcups and I can't believe that 0.005" is a make or break size difference when the shotcups vary so much.

The problem I have had is that recovered shotcups show distorted or enevenly sheared petals. This has been the case in both cylinder bore and my Browning slug barrel with I/C choke and with a couple of different makes of shotcup.

If you get a petal/ball combination that is a slide fit to maybe 0.003" oversize, it should work for cylinder bore. I have oher moulds and found it easier to work with smaller balls in shotcups and and bore size balls over hard card wads.

Longbow

[Nobade]

I don't see that the patched round ball would be a safety problem in your rifled barrel, but normally those barrels have a twist rate way too fast for balls, so accuracy might not be great. Try it and find out if it works or not. I sure wish someone made a rifled barrel with 1:100" or so twist rate for this. But then it wouldn't stabilize saboted factory rounds, so probably wouldn't be too popular.

[GabbyM]

Whatever ball patch combination you use it needs to pass the bore without relying on compression of the ball. From what I read, and I'll just believe that, the balls won't compress. Rather the bore will expand. This is why they don't sell RB off the shelf. You must fit the ball and patch to the choke. Then make sure that's the gun they are shot in.

[Nobade]

Yes, you are correct. Always pust the ball/patch combo through the bore by hand to check if it fits before firing one. It should be just like loading a patched roundball muzzleloader - a firm press but not need to beat it through with a hammer!

[longbow]

I got some pretty good groups of 2" +/- at 50 yards using 0.735" round balls in a fully rifled barrel. Twist was 1:36". I agree it is fast for round ball but it did work much better than I expected. I did not shoot further than 50 yards so do not know if accuracy would hold up at longer range. The gun was borrowed.

They are a little oversize but even wheelweights swage easily as there is so little meat at the equator.

Not sure how well a patch is going to make the transition from hull to forcing cone/rifling but it would be interesting to see your results. A patched 0.690" or 0.715" ball may work and certainly shouldn't present a safety issue. It may not grip the rifling or may lose the patch but certainly shouldn't result in over pressure if loaded for the weight.

0.690" ball in a shotcup may also work for rifled barrel. It is worth a try.

Keep us posted.

Longbow