I have a NEF..H&R,(Wish it was H&H,lol) whatever single shot 20 bore rifled slug hunter.
Massive bbl wall thickness, even at the muzzle.
It was supposed to shoots Sabots,but I wanted old school so I slugged the bore back about a decade ago, n had a brass ball mold made by some guy in England.Very nice mold/mould too,by the way
I was never great with a Micrometer....I want to check my ball size...ok, no jokes here, lol...:)
Should my balls be the exact groove size?.
It used to do a clover leaf at 75 yds.....pretty target , but one Ugly gun..:)
cheers
franc

I haven't shot it in a few years, n want to.
Want to make sure Im ok.
I just used a low pressure 20g 1oz load of unique (about 7000psi), cut the petals off a 20g wad, added some felt wads, put it & the ball in a Remington yellow case with the crimp cut off, n put some crisco ontop .The Remingtons seemed to fit the ball nice, didn't even have to crimp it,as it was a snug, not tight fit.
I tried Winchester AA cases, ball wouldn't fit with out way to much force.
I was thinking my margin of error was that a 20bore slug is a good bit less than an ounce.
Am I mental?...these bbls are wicked thick, 1/8th+ at the muzzle
Franc

Can some one help with ideal size for the 20bore round ball as compared to the measurement of the widest part, the groove, of a rifled bbl.?...Ideally should it be sized to the exact width of the groove diameter?
That was my impression?
Sorry if this is a dumb Q, but I know very little of rifling, dont want to mess up...
Please help,
thanks
Franc

Most everyone I know uses a ball of groove diameter or a thou or two larger.

hello Roger,i thought .004 (.002 PERSIDE)to compensate for irregular bore size.and have a good consistent seal, or use a softer alloy

ok guys, thank you, I believe I am good
cheers
franc

So, how does it shoot? We gots to know...planning on a 20 ga double slug gun build myself.

xs..its been 10 years since i shot it with the load described, its a modern H&R/ NEFsingle shot rifled gun, with a decent scope...like i said in my first post ,it would clover leaf three balls at around 75yds...also like i said...pretty target , but kinda ugly gun, lol
I have yet to start shooting it again, but i will
franc