Round ball in a modern inline grouping poorly


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poihths
May 18, 2012, 08:44 PM
I have a CVA Accura 50 caliber that shoots 295 grain conicals (actually Powerbelts) very well with White Hots. I thought I'd like to shoot something cheaper, so I picked up some Hornady .490 round ball and some Cabela's .010 patches. I tried them with the White Hots and the gun spews them all over the place; the group is about 15 inches at 25 yards.

Is this just inherently a bad match - something to do with twist rate or rifling depth or whatever - or is it worthwhile to continue playing with this, using a different propellant and charge, or whatever?

The CVA has a 1:28 twist 27 inch Bergara barrel. I'm getting about 1550 or so fps on the Powerbelts. I haven't chronographed the round ball.

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farmerted
May 18, 2012, 08:59 PM
While no expert, I have shot a whole bunch of round ball in my Pursuit Ambush. It is minute of squirrel accurate to boot. What I would try, the cheapest thing first, is a thicker patch. The .018" pillow ticking is real snug, but is what has worked for me. YMMV. Also, I haven't tried the round ball load with more than 60 grains of 2f. Your velocity makes me think that the load is hotter and that the patch and ball are "stripping the bore", not grabbing the rifling on it's way down the barrel. Just some ideas.

Busyhands94
May 18, 2012, 09:06 PM
I'd suggest lighter powder charges. My Traditions Frontier has a 1/48" twist and doesn't throw round balls well at heavier charges, I'm getting fliers. But with lighter loads it's fine.

Another thing to keep in mind is that round balls like slower twist barrels, conicals and sabots require a faster twist to stabilize.

Best of luck to ya! :)
~Levi

dprice3844444
May 18, 2012, 11:35 PM
http://www.go2gbo.com/forums/index.php?topic=215590.0

says 64 grains of pyrodex

alsask
May 19, 2012, 12:13 AM
For roundball in a .50 you would not want anything faster than 1/48". 1/28" is fast for a pistol shooting .50 cal roundball.

T Bran
May 19, 2012, 12:28 AM
I agree with slowing it down a bit and using a bit thicker patch to ensure better traction on the rifling.
I have no experience with White hots other than seeing them in catalogues. My CVA inline shoots them into a decent group using 60 grains of Pyrodex. My Hawken hunter does well with up to 90 grains but has a much slower twist. Both get a very tite patch but I never measured the thickness of the cotton fabric [stole it from the wifes supply].
I just smear a little bore butter on the patch to ease the loading process but still have to thump the ball starter pretty good to get them going.
Hope this helps.
T

Jaymo
May 19, 2012, 12:28 AM
What about buying a Lee REAL mold and cast your own conicals for practice?

josmund
May 19, 2012, 06:26 AM
You'll struggle to get the PRB to shoot well with a 1/28 twist.

For discount shooting consider a box of 100 Hornady XTP's in a 200 grain. It will cost you about $22.

Then you can buy Harvester 50 / 40 Sabots for about $6 per 50. You're at about 34 cents a shot without powder. This can take a smaller powder charge and be very accurate.

ThorinNNY
May 19, 2012, 10:19 AM
I second Jaymo`s suggestion about getting a Lee REAL mould and casting your own bullets. REAL means Rifling Engraved At Loading.
In addition to giving you the accuracy you want, you won`t have to bother with patches or plastic sabots, your barrel will last a lot longer. It`s not the lead ball that causes barrel wear, it is the patch. Plastic sabots can leave something behind in the barrel that can be a pain to clean out.
Plus, casting your own is a money saver.

arcticap
May 19, 2012, 03:44 PM
I can see trying it with 1 White Hots pellet but not 2 of them.

straight-shooter
May 19, 2012, 05:02 PM
I agree that 1:28 twist is not ideal for roundball. On the other hand i've never personally tried it but the consensus is just that. I only shoot .44 cal in a sabot FMJ from it. My traditions Hawken 1:48 twist likes the roundball.

frontiergander
May 19, 2012, 05:22 PM
If you'd like something cheaper, buy a 50 pack of the MMP sabots " HPH-24 Black" and then buy the 260gr harvester scorpion PT Gold bullets to do with it. This guy sells the bullets for 36 cents each and will do bulk orders. Give Carlos a call and he'll set you up.
http://www.frontiermuzzleloading.com/t3375-ed-s-gun-shop-blackhorn209-store

The REAL bullet doesn't do well in the 1:28 twist either, I have a bunch of CVA's as I do a lot of testing/reviewing and I bought the REAL mold just for them only to find out they hated that twist.

It'd love the 370gr Maxiball mold that Lyman makes. I get 1 1/2" groups @ 100 yards with 70gr Blackhorn209 with my Wolf and Apex.

poihths
May 21, 2012, 09:18 PM
Thanks, everybody! Lots to think about and tinker with. Gotta love it!

zimmerstutzen
May 22, 2012, 10:47 AM
Twist alone is not the determining factor, otherwise round ball pistol barrels would not be offerred in fast twists like 1 in 22.

in -line rifling is very shallow in addition to being fast. Round balls can shoot with accuracy in most in-lines. It requires compensating for the difference in rifling. 1) a much lower powder charge is required. In a fifty caliber, maybe 30 grain charge tops and 2) a very tight patch ball combination so the rifling can grip the ball and spin it.

A top target shooter I once competed against built an extremely accurate flintlock offhand rifle using a barrel blank rifled for smokeless cartridge guns. It was a .375 barrel and he did use a tight patched ball combo over a very small powder charge, maybe 20 grains. He used a mallet to start the PRB. It was peculiar in many other ways as well. the barrel was probably an inch across the flats, but only about 24 inches long. Woody won alot of offhand matches with that gun. As I recall, he used 375 balls meant for revolvers and a thin tightly woven patch.

Loyalist Dave
May 24, 2012, 09:36 AM
To expand on Zimmerstutzen's point...,

The twist rate alone, indeed, is not the only factor. The Pedersoli Jaeger is 1:28 twist, and shoots patched round ball over 70 grains of 3Fg very well, and the Pedersoli 3-Band Enfield is a 1:78 twist, and shoots miniball style conical bullets very well.

I'd suggest you try something similar to what CVA recommends, and there are several different styles of pre-cast conicals as well as mold for such that may give you a break on price, but still shoot well. You may find you need to "paper patch" an all lead conical to get it to work like the plastic skirted powerbelts.

LD

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