20 ga RB/pumpkin full bore or wad?

[JustinP]

I have a 20 ga Remington 870 smooth bore with screw in chokes.
I seem to think I need to load up some round balls.
I have no real need to do this, but I've never let that stop me before.
It's really just a project to tinker with for me.

I've spent an insane amount of time reading old posts here, and other sites as well.
As far as I can tell the general consensus is, there is no general consensus as to full bore or ball in a wad.

I only have telescoping bore gauges so I haven't measured my bore yet, I'm going to check a couple places and see if I can get it measured.

I'm leaning towards trying powder coated full bore balls instead of balls in a wad. Powder coated to prevent leading was my thought. My gut feeling is it will be more consistent and more accurate.

I don't have any molds even close to what I might need. So I will need to find one or have one made depending on what size I decided I need.

I guess my question is, Am I going down the right road chasing this full bore idea?
Does it even matter? Is a good fitting full bore equal to a good fitting full wad accuracy and consistency wise?

[725]

It has been a good and rewarding effort or me. I like round balls, however I put 'em in a plastic wad with a cork base. Have found a star crimp beats a roll crimp (for me). I've PC'd a jar of balls but have not yet gotten around to experimenting with a load. So much to do and so little time to do it!

[JustinP]

Thanks 725

Have you been satisfied with your accuracy in the wads?

[longbow]

This is a question I am still trying to answer... To wad or not to wad?

The wad adds to the variables but for smoothbore I don't think it makes much if any difference.

I should start by saying I load for 12 ga. not 20 but same principles should apply. I found that using RB's in shotcups that are a good fit or using 0.662" RB's cloth patched into shotcups to get a good fit to bore I got very good accuracy from smoothbore resulting in +/-4" groups at 50 yards. With good hulls and loads most groups were between 3" and 4" which is better than most slugs give me.

As for full bore, I also shot 0.735" RB's over hard card wad column after unsuccessfully trying to use a trap wad with petals cut off. The 0.735" RB's are a little oversize but swage down easily and also gave me similar group size of 4" at 50 yards.

I find it quicker and easier to load RB's into shotcups than to make up wad columns so tend to go that route. Also, an RB in a shotcup is more choke friendly than a full bore RB is should one find itself in a choked gun.

If you go the RB in wad route, I suggest using at least one nitro card wad in the bottom of the shotcup and I have also found that it seems to help if you put a scoop of Cream 'O Wheat into the shotcup before the RB is seated... just enough COW to fill the airspace under the ball and make a seat for it. Without support under the ball I have found that shotcups tend to extrude up around the ball causing bad things to happen like gas seals failing, bottom of shotcup cracking, etc. Randy Buchannan uses felt wads under his RB's with good success too but same principle, to support the ball and protect the bottom of the shotcup.

Your fit of RB/shotcup to bore should be a good stiff push through. For a rifled gun or rifled choke I suspect you would want a very tight fit to transmit the rotation through the wad petals to the ball.

If you go full bore RB I'd suggest about 0.003" over bore diameter would be good. A bore size or somewhat under bore size ball can roll in the bore and you don't want the RB to leave the bore with any random spin on it. A little over bore diameter makes sure it leaves centered and no spin.

You can load using slug loads for equivalent weight if you want fairly peppy rounds or use birdshot load data for equivalent weight for more pleasant shooting. Maybe not quite as much issue with 20 ga. as 12 ga. A full bore 12 ga. ball weighs about 1 3/8 oz. so a substantial slug!

Not sure what RB sizes suit 20 ga. shotcups but for both full bore or wad size RB moulds you can order any size you want from https://www.ballmoulds.com/ if you can't find what you need elsewhere in commercial moulds.

For 12 ga. I have 0.662", 0.678", 0.690", 0.715" and 0.735" moulds, all Lyman and all cast somewhat oversize. I think 0.575" RB's fit 20 ga. shotcups and something about 0.615"+ should work for full bore.

Have fun!

Longbow

[725]

My experience has been with 12 ga. round balls. My thoughts are to get the wad / ball combo pretty tight to the bore, even to the point that the wad gets a little compressed on the sides where the ball / wad is moving through the barrel. I've never had a choke and I'm shooting cylinder bore. I'm very, very satisfied with my accuracy & the terminal effects in both rifled and smooth bore. I'll go looking for my data book for the details on how I load the shell. Long time ago I wrote a detailed thread here about "success with 12 ga. round ball" (or some such title.) It may still be in the archives. I think by using a regular RB and having it PC'd, you might just be on target with getting a snug fit for the wad / barrel relationship. Without the PC I'm thinking it may be too loose in there. In my case, I had Jeff Tanner cut a RB mold to produce a .702 ball (no PC). The added size from PC'ing may make a regular ball fill out to give you the snug fit I was after.

[JustinP]

Thank you both very much for all the great information!

I think I've read older posts both of you have made in the past too.

I measured my bore at .6191, but I'm not fully confident in that number. My bore gage was barley long enough to reach past the choke. And the way I had to do it left a lot of room for error.

I most likely will order a mold from JT. Am sure I will have to if I go the full bore route.

But after talking with you guys, I'm not so sure I won't go the wad route. Oh who am I fooling, before it's all said and done I'll do both and have a small fortune in molds and component tied up in doing it too.....LOL

[725]

Oh, brother, can I relate!

[FullTang]

Thank you both very much for all the great information!

I think I've read older posts both of you have made in the past too.

I measured my bore at .6191, but I'm not fully confident in that number. My bore gage was barley long enough to reach past the choke. And the way I had to do it left a lot of room for error.

I most likely will order a mold from JT. Am sure I will have to if I go the full bore route.

But after talking with you guys, I'm not so sure I won't go the wad route. Oh who am I fooling, before it's all said and done I'll do both and have a small fortune in molds and component tied up in doing it too.....LOL

Hi Justin,

I foresee much heartache in your future, as you pursue this elusive Great White Whale of smooth bore accuracy. Perhaps as a way of mitigating the pain and financial calamity, you might first try some of the Lyman-style, diabolo slugs such as these: http://gardnerscache.com/20ga_350gr_...00pc_only.html
If nothing else, these will provide a baseline level of accuracy that you can expect out of your gun, and this won't break the bank. I've found that this style of slug (in 12 gauge, at least) to provide the best results with the least cost and effort.

[JustinP]

Buying tons of unnecessary and unused guns and loading components is expensive and foolish. But at least I'm not a golfer......lol

I would think the shuttlecock style like those would tumble and keyhole?

[longbow]

You might also consider a rifled choke tube. Some people report very good accuracy using rifled choke tubes. Some not so much but I suspect that slug fit is even more important with a rifled choke tube than fully rifled bore because for wad slugs in particular, they slam into the rifling at full velocity so if there is any slippage the slug won't pick up the spin. A full bore slug should be a better choice there.

Again, no personal experience but I have read that the Lyman 20 ga. sabot slug is not accurate from smoothbores due to proportions. Apparently the 12 ga. sabot slug does fairly wel from smoothbore but the 20 ga. generally does not. From rifled bores both reortedly do well and should also do well from reifled choke tubes if wad fit is good.

Hopefully someone that has tried will post with real results.

I am a smoothbore guy so limited experience there.

Longbow

[JustinP]

You might also consider a rifled choke tube. Some people report very good accuracy using rifled choke tubes. Some not so much but I suspect that slug fit is even more important with a rifled choke tube than fully rifled bore because for wad slugs in particular, they slam into the rifling at full velocity so if there is any slippage the slug won't pick up the spin. A full bore slug should be a better choice there.

Again, no personal experience but I have read that the Lyman 20 ga. sabot slug is not accurate from smoothbores due to proportions. Apparently the 12 ga. sabot slug does fairly wel from smoothbore but the 20 ga. generally does not. From rifled bores both reortedly do well and should also do well from reifled choke tubes if wad fit is good.

Hopefully someone that has tried will post with real results.

I am a smoothbore guy so limited experience there.

Longbow

My Thompson Center .56 smoothbore muzzleloader is what started me down this path with my 20 gauge. Which I think is also why I'm drawn towards the round balls for the 20. The smoothbore is just plain fun, and for the area I'm in and what I use it for it's super versatile.

If I stumble on a good deal for a used rifled choke I might try one. But for round balls I don't see it being an advantage. But I guess every single gun is different, so who knows.

I think I've made up my mind to see how well I can make a powder coated full bore ball shoot.
I really need to have someone with a bore gauge confirm my measurement before I go ordering a mold though. Then on to load development.

It'll take me a while yet, but I'll do an update when I get there. With good news or bad.....

[longbow]

Yes, RB's are easy to cast, easy to load and are fun to shoot. They may not be the most efficient projectiles but when shotgun size they pretty potent! I like round balls!

If you want to slug your bore you could drill a hole of about the same size as the bore in a piece of aluminum or even hardwood then cast a slug in it. a 5/8" drill bit should work for this. It is handy to have a lathe because you could cast oversize then turn down until just a bit larger than the bore, then slide it into the chamber and use a piece or aluminum or brass rod (softer than barrel steel) to pound the slug into the bore. Soft lead swages easily.

If too big, turn it down some, if too small then smack it with a hammer to make it swell a bit then try again. If you cast a piece of threaded rod into it that gives a lathe or drill press chuck something to hold while you turn it to size. A drill press and file should do it if you don't have anything else.

Alternately you could order pre-cast round balls from Track of the Wolf:

https://www.trackofthewolf.com/List/Item.aspx/127/3

They have 0.626" which should work for slugging the bore but are oversize to shoot.

20 ga. is nominally 0.615" bore so maybe someone has slugs or round balls they can send you to slug with? Where there is a will there is a way! You just need a near bore size slug or ball that can be swageed into the bore.

Longbow

[FullTang]

Buying tons of unnecessary and unused guns and loading components is expensive and foolish. But at least I'm not a golfer......lol

I would think the shuttlecock style like those would tumble and keyhole?

You're right that the proportions of the 20 ga Lyman-style sabot slug are different, but I do like Longbow's suggestion of a rifled choke tube to address this.

I used to shoot a lot of black powder, and one of my shooting buddies had a 20 gauge smoothbore muzzle-loader, which was capable of surprisingly good accuracy---now and then. It was always quite sporadic, with plenty of flyers. I guess if the stars align and the ball fits just right, and the sprue is oriented just so, you can hit what you're aiming at. Or, you could miss by a foot or two.

It always seemed like a wad could provide the solution, perhaps by keeping the ball from spinning down the bore, but my experience with RBs in wads was never great. Full bore RBs in a rifled barrel, though, always give me outstanding accuracy in any one of my 3 rifled shotguns.

[Earl54]

Get an egg fishing weight and use that to slug the bore. I start it into the bore from the chamber(oil the bore,it helps)and once it starts you most times can push it by hand(except if you run into one of the old Ithaca "Deer slayers" model 37 pumps, cause the have a tapered bore)and feel tight and loose spots.

[JustinP]

Thanks guys!

I've thought about slugging my barrel.
Most of my lead is on the harder side though.
I need to dig through my found object bucket and see if I can come up with a little dab of soft lead.

I do have a lathe and a mill, so I could make a quick slug mold.

Full Tang, you got me thinking more about trying a rifled choke now.

[murf205]

I have not delved into 20 ga territory (YET) but as far as my fully rifled Hastings on my 870 goes, my success has been with a .735 rnd ball powder coated and loaded in a cushioned wad with the petals cut to allow the full diameter of the ball to be engaged in the rifling. In other words, petals cut just enough to hold the ball. With sabots, the gun either likes them or not. IMHO, it has been NOT. I am a rnd ball homer. BTW, it sure is easy to see those big holes in the target.

[JustinP]

murf205, I didn't realize it until you mentioned it but hole size must be why I shoot my 22 less as I get older!

[Hogtamer]

Cast a ball 5-10 thousandth over bore size (soft lead!) and it works great out of smoothbore. Easily punch a big hole through a deer at 50 yds. A full bore ball down a rifled barrel will leave you scrubbing lead for a week.

[JustinP]

Cast a ball 5-10 thousandth over bore size (soft lead!) and it works great out of smoothbore. Easily punch a big hole through a deer at 50 yds. A full bore ball down a rifled barrel will leave you scrubbing lead for a week.

Thanks Hogtamer!

My lead stock is firmer, around 12 BHN.
I was going to shoot for 1-3 thousandths over with the lead I have on hand.

You thinkin' I'd be better off going softer and in that 5-10 range? 10 seems big to me, but I never use soft lead either.....

[longbow]

I used ACWW 0.735" RB's with no lube in both smoothbore and rifled gun with no problems. I shot the most through my smoothbore but I put 15 rounds through a friend's rifled 870 with no leading.

I certainly wouldn't say not to tumble lube the RB's or maybe use a lubed wad under just in case, but I had no issues using naked hardish lead ball that actually cast about 0.738" so about 0.005" over my fat bored Cooey with 0.733" bore.

The rifled gun had 0.727" groove diameter so pretty tight but again, no issues.

I'd expect soft lead to smear but the only slugs I have cast from pure lead were the Lyman Fosters which are grossly undersize. They did bump up but again, I had no leading issues in smoothbore.

Longbow