Bullets Keyholing, what to try next?

[SRM]

Just got back from the range with my encore and a TC custom shop barrel in 50 cal, 1:48 twist.  Barrel was purchased to I can shoot heavy conicals.

Bullet - Hornady Great Plains - 460 grain Hollow base, flat point
Charge -100 grains pyrodex select.
Winchester 209 primer
Leuopold scope
25 yard target


First shot low at 7-o'clock
second shot 7 inches away and high at 3-o'clock
third shot way left at 9oclock and key-holed through the target
fourth shot next to second shot
Started raining and I went home

With the keyhole and obvious lack of accuracy, should I start by increasing charge, decreasing charge, or try another bullet?

Have 444 grain power-belts on hand to try also.

Any help would be greatly appreciated.

Scott...

[johnt]

 Hi SRM,
 Might wanna double check yer post

460gr in a 50 1-48??
more than willin ta help,,,,,,,,

[SRM]

 Hi SRM,
 Might wanna double check yer post

460gr in a 50 1-48??
more than willin ta help,,,,,,,,

Double Checked, nothing wrong.  I want to shoot the 460 grain bullet in the 1:48 encore from the TC custom shop.  Keyholing with 100 grains of powder.  Obvious instability.  The question is to increase the charge or decrease the charge?

Scott...

[johnt]

Thanks for the return srm, I had no idea anyone marketed that large a projectile for the 50.,seem's cva has a 530 also!
 IMHO,I enjoy my .54. With a 230gr PRB or a 320gr REAL I can hit at 100 purty darn close. Gonna try .380 REALs soon.
 All Bull huwey aside, shooting 460,, one must consider the flinch factor!
 Then ya gotta figer if the "sabot" "skirt" or "patch" will impart too the projectile the proper rotation for its' length in the given caliber, with the depth of groove and bore condition for proper accuracy!
 If it is a Custom TC,and it won't shoot what ya what,then ask the custom TC shop how ta shoot it. Or ask CVA,.
 Me? take the scope off. And I'll shoot it better than 7" at 25 lookin down the bore.
 silly? er what?

[Charles/NM]

IMHO, a 1 turn in 48" barrel isn't going to stabilize a bullet heavier than around 370 grains, maybe 400 max.  Try a 370 grain Maxiball.  Should give you a 3/4" group at 50 yards.
Charles/NM

[johnt]

That's what I was going to say Charles!
 But it's a "custom!"" Encore!" Barrel,that's gotta be different than all the others!
 I guess 460 grn projectiles or even 530grn for the .50 must stabilize in that gun. After all you can buy'm so it much shoot,, right?
 Whattaya figer? 460grn in .50? 1 1\8"--1\14?"??

Sorry for the sarcasim SRM, why do you want to shoot such bloody huge rounds?
  I could "hip shoot", or throw rocks,,better at 25 yrds. Spear?? 75ft!??

[Snowshoe]

I have a Lyman Deerstalker in .50 cal with a 1 in 48" twist, and it will shoot up to 370g bullets but not much more. The most accurate is in the 320g range. I had some 378g  bullets that keyholed on me, so I sized them a little larger. It was a little tough loading, and leaded up the bore,  but they shot very well. If you want to shoot big bullets you need at least a 1 in 32" twist.

[Ironwood]

I have to agree with Charles and Snow.  It seems like the 1-48 twist would have trouble stabilizing a bullet of that length.  Of course there are several other factors that could be causing the problem.  If the bullets are the proper diameter, well lubricated, but will not stabilize at maximum charges then I would think the twist rate can't handle that weight/length of bullet.  

You might want to try something like the Hornady 240 gr. XTP (green) sabots just to see how well the barrel will shoot.  If a charge of around 90 grains of Pyro RS and that bullet/sabot doesn't give you clover leafs at 25 yards then I would seriouly look at the barrel it's self as being the problem.

[pendennis]

Scott, there's no way a 460 grain bullet can be stabilized at 1:48".  I shoot 460 gr bullets in my .45 caliber Pedersoli Tryon Creedmoor.  It's bored 1:20", and I can shoot as little as 65 grains of GOEX fffg, and get 2" groups at 100 yards.

I also shoot a Sharps 45-120 using a Lyman 535 grain bullet and 80-100 grains of GOEX fg, and it barely stabilizes the bullet at 100 yards.  The barrel is 34" in length and bored 1:18".

The 1:48: twist is a compromise from T/C.  You can get a .45 caliber round ball to stabilize, and it will shoot got groups at 100 yards.

[clodbuster]

SRM-Change the bullet!  The 1 in 48' will probably not stabilize such a long bullet, just not enough spin.  Something around 370 gr will probably work much better.  As with reloading centerfire cartridges, the bullet is the most important factor.  If your barrel doesn't like a particular length or weight it just wont shoot it well.  With bp the charge weight needs to be varied in 5-10 gr increments to find the optimum.  Ergo loose powder.
Wipe between each shot.  I use 1 wet, then 1 dry or just 1 dry in another gun.  Hope this helps

[johnt]

Thanks Clodbuster,
  I wonder how many folk's new to the idea really understand that a heavier bullet in the same caliber is longer than a lighter one? Or how full lead vrs.sabot vrs. powerbelt or PRB really effect's twist in a given ratio to deepth of groove and projectile choice? :oops:

[KING]

:-D   Goint to loose a lot of hair if you want to keep shooting that type of projo out of a 1:48 twist.  The .50s that I have will not go over 400 grns without keyholing.  Some will do it a lot,or you get a projo completely sidways into the target.  Not to conducive to accurace at all.  Drop the bullet weight to around the 350 is you are shooting a plain lead or a cast projo.  LIke the guys said,try to use a lighter bullet with a differant plastic wad thingie also.  Your powder amount will give the needed" OOOOOmph to drop a whitetail,but you should be shooting a cloverleaf at the 25 yard mark with your load,so experiment a little.  You also might wanna check that hollow base and attempt a solid base.  Wont hurt.  Stay safe.........King

[dbm]

Scott, there's no way a 460 grain bullet can be stabilized at 1:48".  I shoot 460 gr bullets in my .45 caliber Pedersoli Tryon Creedmoor.

... and I shoot a 560 grain bullet in my 1:48" original Enfield, cal .577", that stabilses. Comparing the original post calibre with another is moving the goal posts somewhat as they'll have different characteristics.

David

[SRM]

Back to the range on Sunday.  Re-tried the 460 hornadies - no keyholing, but still very lousy groups.

Then I tried the 444 power belts with 90 and 100 grains of pyrodex.  25 yard groups were unexceptable at 4 to 5 inches.

Off to the Scheels for some 348 grain powerbelts.  Once again, unexceptable groups with 90 and 100 grains of pyrodex.

On a whim, reached into my goodies box a retrieved the Goex FF that I shoot in my TC 54 New Englander.  100 grains of FF with the 348 produced clover leafs at 25 yards.  Moved the target to 75 yards.  Acceptable 2.5 inch groups.  Grabbed the 444 power belts, same charge/same target, and proceded to land the next 4 shots into the same 2.5 inch group.  Go Figure???

Removed the scope, sighted in with the open sites and now Dad can hit a large soup can at 75 yards with the TC open sites.

Taking the Encore, Dad, and the 444's to Colorado next week.  I'll shoot my New Englander and 450 grain PR Conical.

Why such heavy bullets?  I prefer the heavier weights because they usually leave two holes that make tracking without snow on the ground much easier.  I realize that shot placement is essential and I have rarely had a double lunged elk go more than 75 to 100 yards.  But, once upon a time, years ago, with a lighter bullet, I hit a cow to far back (Based upon the blood spot on her side, base of lungs and liver)  I lost her, when I lost the blood trail.  Switched to a heavier conical and reasonable charge and have had pass through ever since (5-elk).

Thanks for all comments.  I do intend to try some 370 range conicals in the encore for deer hunting.

SRM...

[tommy4toes]

SRM -
the only thing I can think of is REAL black powder "hammers" bullets different than the substitutes. A whole lot depends on the hardness, but I can tell you that with substitute powders, bullet diameter needs to be bigger - on the order of .002 or better. i think it's a burn-rate thing. Can you get oversize 460 grainers to try>?

t4t

[tommy4toes]

BTW -

if ya shoot round balls, they cant keyhole !!!!!!!!!



t4t