Lyman roundballs measured at .735", Benelli bore slugged at .723"...safe to shoot?

[mojomandan]

Hi guys,

I have a Benelli Supernova Tactical shotgun with 18.5" smooth bore barrel and really wanted to try shooting a Lyman .735 roundball. I have had ok luck with the Lyman 525 grain slug (6" groups at 50 yards-good enough for me), so wanted to see what round balls would do after reading some other positive reviews.

Since I wanted something closest to full bore, I bought the .735, cast some from melted lead shot (all balls measured .735"), and slugged my Benelli's bore with one round ball. It did not take a lot of force to punch the ball through with a wooden dowel, and it created a .177" diameter-wide flat "equator" around the ball. The "equator", and therefore my bore, measured .723" in diameter.

I know a lot of people say the difference between bore and projectile should be .003 - .005" (I think). Should I forget this size of round ball since it is .012" larger than my bore? :sad: At the very least, I know I will have to completely trim off wad petals if I do.

Thank you!

[longbow]

Well, I shoot 0.735" round balls through my smoothbore but it runs 0.729" bore. I got warnings but did just as you did and tapped a ball though with a mallet and dowel. It went very easily so I did not worry. It also shot very well.

I used the same load in a borrowed Remington 870 with rifled barrel and again they shot very well with no signs of pressure or problems. That barrel ran 0.727" groove.

However, at 0.723" that is getting a bit tight for my liking. I can't say it isn't safe but that seems a bit much.

You can order whatever size ball mould you want from Jeff Tanner:

http://www.jt-bullet-moulds.co.uk/moulds.html

I do not have any of Jeff's moulds but have been told they are very nice, not expensive and cast well. I would recommend 0.725" for your gun.

I also recommend using a plastic over powder gas seal then hard card wad column. Round balls tend to destroy shotcups with cushion legs because the unsupported base and leg want to extrude around the ball. At least use a nitro card wad or two under the ball if you use wads with petals cut off. A scoop of COW under the ball also seems to help. I think it compresses and forms a nice seat for the ball.

Having said that, if ball fit is good and you work up a good load you should expect to get 3" to 4" groups at 50 yards. So far I have to say other than factory Foster slug loads and specialty slugs like Gualandi and AQ, I have not had any home cast slugs shoot as well consistently from my guns as round balls do to 50 yards.

Much beyond 50 yards the balls pick up random spins and groups start to open up.

Longbow

[mojomandan]

Guys,

Thank you for your information-filled responses! I will heed your warnings and go with something smaller. I guess the only thing to do with my current ball mold is sell on eBay :sad:

And the nicely cast round balls...back to the melting pot!

[FullTang]

One thing in your favor is that this gun is rated for 3.5" shells, so it can take 14,000 psi all day long. I have the same gun, and I've shot a lot of oversize slug-in-wad combinations with no problem at all. Not saying it can't be blown up, but the added pressure from this amount of "squeeze" won't be all that much.

[Hogtamer]

"Lighter RBs at higher velocity will shoot lower than heavier, slower combinations."
Trying to figure that one out over my grits and eggs this morning, Excess. Help me understand!

[pipehand]

"Lighter RBs at higher velocity will shoot lower than heavier, slower combinations."
Trying to figure that one out over my grits and eggs this morning, Excess. Help me understand!
I'm not excess, but what I think he means is that the heavier ball going slower will be of higher momentum, causing greater muzzle rise (recoil)/while having longer barrel time. This causes the ball to exit the barrel with the gun pointed higher. It's not about trajectory, which is what happens after the projectile leaves the muzzle.

[TonyfromItaly]

hello mojomandan, if you use soft lead, the max oversize you can shoot is .04 mm or 0.0015". The barrel will function as a resizer at the equator part of the ball.

[W.R.Buchanan]

mojoman: look thru this section and find the thread by XS650 about shooting .665 round balls,

I load .662 round balls for my M500 for 3 gun and there is a thread about that as well. These loads are my normal 12 ga Trap Loads, with a Ball and 1/4" thick Felt wad substituted for the shot load. The crimp closes perfectly and they shoot well out to 50-60 yards.

I just posted pics of those loads on eh 20 ga slug thread so you can see what they look like.

Randy

[longbow]

mojomandan:

Something else I guess I should mention, though I have not done this myself, is you could make a hammer swage die (very easy) to size those 0.735" balls down to your bore diameter. That will put a "belt" around the equator then you load those on a gas seal and card wad column. Not sure I would trust that the "belt" would remain lined up with the bore but others have claimed this works.

It may be an option. I would recommend either a custom mould to produce a +/- bore size ball or go with an undersize ball that fits a shotcup. 0.662"and 0.678" are Lyman standards and both work well for me. The 0.665" I am not sure of but a couple of folks here (Randy?) seem to have moulds of that size. Track Of the Wolf has scissor moulds in a variety of non-standard sizes as well so you might look there.

There is a solution!

Longbow

[W.R.Buchanan]

Mine is a Lyman .662. It would probably do .665 with harder lead than plain wheel weights.

Randy

[longbow]

Randy:

Do you "patch" the 0.665" balls?

I find that my 0.662" balls (IIRC they cast at 0.663") are a bit loose in standard shotcups. They are a good fit in steel shot shotcups but loose in standard thickness shotcups. It's funny that all my Lyman round ball moulds cast at least 0.001" over stated diameter while my Lyman boolit moulds tend to cast at or under stated diameter with the same alloy.

I have used both paper and cloth to patch them and both work well. I suppose a donut wad under the ball would work too and might be easier. I mostly shoot the 0.678" balls now as they are a perfect fit in my standard wads.

Just curious.

Longbow

[W.R.Buchanan]

LB: no, I just load them in a Claybuster WAA12 clone with a 1/4" felt cushion wad. The .662 dia. plus the thickness of the wad petals is very close but slightly smaller than the bore size. literally .002-.004 smaller or close enough.

Randy

[longbow]

I'll bet that felt wad forms a nice "dish" for the ball to sit in. I find mine are a slight rattle fit without the patching. A thicker petal wad might just do it but then I have the 0.678" ball mould which for my wads is a perfect fit, so... Both do shoot well when loaded right though.

Longbow

[mojomandan]

Guys, many great suggestions as always. After reading all of your discussions, I think I will try a smaller round ball with wad. Unfortunately, I rarely have time to cast lead and go to the range to try things out, so it may be a while before I report back.

[W.R.Buchanan]

I must ask,,, Do you have your MOJO workin'?

Randy

[Markbo]

What.. you don't have a Lee .723" sizer??? ;)

[mojomandan]

I must ask,,, Do you have your MOJO workin'?

Randy

Always!


What.. you don't have a Lee .723" sizer??? ;)

Dammit, I knew there was something I forgot to buy!

[TonyfromItaly]

Hello, if you take the barrel off the Benelli, there should be stamped the bore diameter in mm, at the beginning of the barrel. I think it should be 18.5 mm. If that is the case, a .735 inch ball corresponds to 18.67 mm. In that case, a ball cast with soft lead would be safe to use.