Bullet tumble???

[COLOelkman]

So I shot my White Ultra Mag today, shooting some Bullshops 460 gr. with 95 gr. Pyrodex P. Shot at 50 and 100 and things looked OK. So I tried some of the White Power Punch 460 gr. conicals and they shot OK as well, but not as good a group as the Bullshops. So I decided to shoot my Super 91. Shot 2 at 50 and it wasn't a great group but OK, I then shot at 100. First 2 were maybe 3 inches higher than the Bullshops then problems followed. The next shot I didn't think hit my 3'x3' target. Thought maybe I forgot to put a bullet in??? So shot another and it hit 13 inches low and sideways. Upon further inspection, I think shot 3 hit the far right side of the target sideways also. I was using 95 gr. for all shots so kinda surprised to see what happened to shots 3 and 4 of the White bullets. I did feel the barrel and it wasn't at all hot and I really wasn't shooting fast. I run 2 patches down the bore after every shot and they all seemed to come out about the same. Anyone ever have bullets tumble like this and any ideas what might cause this?

 

[diablo]

Weird. Heat shouldn’t make much difference with a conical. Were you using a wad of any kind? That will generally help.

 

[D33RHNTR]

I’ve had the same thing happen if I was shooting a shorter bullet (hornady sst) combined with a magnum charge. If I changed to a longer bullet (Barnes MZ) with the same charge or backed off the charger with the shorter bullet, they stopped key-holing.

 

[COLOelkman]

I’ve had the same thing happen if I was shooting a shorter bullet (hornady sst) combined with a magnum charge. If I changed to a longer bullet (Barnes MZ) with the same charge or backed off the charger with the shorter bullet, they stopped key-holing.

The weird part is that the first several shots were fine, then 2 tumbled so I stopped shooting. I've read that a loose fit could cause tumbling and they all loaded similarly but relatively easy. I felt minimal resistance when pushing the ramrod but that was true for all the bullets.

 

[Katoom]

Assuming these are lead conicals? And you are lubing them? If so, sounds to me like that powder charge is too high for that bullet in your gun, and/or the bullet is undersized for your barrel. It’s also a hefty charge to begin with for that heavy a bullet, high pressure, innacurate, and unnecessary, I hunted elk with a 460 on 75 grains and shot through a cow lengthwise.

Either or both causes could cause your bullet to strip through the rifling and be unstabilized, causing keyholing and inability to group. I’ll bet that an 80-85 grain charge (work up starting with 75) would tighten everything right up. A wool wad under the bullet also is often advisable to maximize accuracy.

Finally, I am assuming that your rifling is a 1/24 or so twist which is good. Slow twist rates (1:48 or more as found on most hammer guns) will not stabilize the heaviest conicals as well since they are too long.

 

[COLOelkman]

Weird. Heat shouldn’t make much difference with a conical. Were you using a wad of any kind? That will generally help.

I"ve not used a wad.

Assuming these are lead conicals? And you are lubing them? If so, sounds to me like that powder charge is too high for that bullet in your gun, and/or the bullet is undersized for your barrel. It’s also a hefty charge to begin with for that heavy a bullet, high pressure, innacurate, and unnecessary, I hunted elk with a 460 on 75 grains and shot through a cow lengthwise.

Either or both causes could cause your bullet to strip through the rifling and be unstabilized, causing keyholing and inability to group. I’ll bet that an 80-85 grain charge (work up starting with 75) would tighten everything right up. A wool wad under the bullet also is often advisable to maximize accuracy.

Finally, I am assuming that your rifling is a 1/24 or so twist which is good. Slow twist rates (1:48 or more as found on most hammer guns) will not stabilize the heaviest conicals as well since they are too long.

Main reason I used 95 gr. is that a well know muzzy shooter uses that with the same gun. I do plan to go down to either 85 or 90. The bullets are lubed but to be honest, the lube is a bit old so adding a bit more probably wouldn't hurt. I also will try adding a wad. My shoulder and cheek will be much happier as it was not real comfortable!!! My cheek is actually swollen a bit today.

 

[matpat]

You are also shooting “P” which is probably closer to 110. Had same problem (tumble) with original power belts. I’d reduce powder charge.

 

[Zeke]

I might be talking out of my rump (since I'm a one-trick-pony when it comes to front-stuffers) but whenever I've seen tumbling, it's because of not fast enough barrel twist for the length of the projectile.

Zeke

 

[elkassassin]

Kinda Like Stuffing A Conical Down a Slow Twist HAWKENS!

I've Got a couple of 600 Grain WHITE POWER PUNCH Conicals You Could Try!

I've Tipped Bucks Over & Lifted Them Off The Earth!

I might be talking out of my rump (since I'm a one-trick-pony when it comes to front-stuffers) but whenever I've seen tumbling, it's because of not fast enough barrel twist for the length of the projectile.

Zeke

 

[Trix4me]

I had some 460’s tumble out of my White when I tried pellets never a problem with loose powder. I never used the pyrodex P.

 

[COLOelkman]

I might be talking out of my rump (since I'm a one-trick-pony when it comes to front-stuffers) but whenever I've seen tumbling, it's because of not fast enough barrel twist for the length of the projectile.

Zeke

Barrel twist is 1 in 24 and many people shoot and recommend this size bullet for this gun.

 

[COLOelkman]

Kinda Like Stuffing A Conical Down a Slow Twist HAWKENS!

I've Got a couple of 600 Grain WHITE POWER PUNCH Conicals You Could Try!

I've Tipped Bucks Over & Lifted Them Off The Earth!

Thanks for the offer but I have several other bigger Whites as well. Not sure there's any 600 gr. in there. A few of the Whites I bought over the years were sold with White bullets so I have a big variety. Might have to try some of the bigger ones at the range sometime but I've kinda settled on the 460 g. size for now as several people have had very accurate result with this size.

 

[cannonball]

I had some 460’s tumble out of my White when I tried pellets never a problem with loose powder. I never used the pyrodex P.

I have a Green Mountain barrel, 45 caliber, 28" twist, 34" barrel. It is a tack driver with real Black Powder. Not so with the substitutes. Figure it?

 

[DSilver]

I had the exact same thing happen. What I figured out is the back of my bullet was beveled, but the bottom of my sabot was flat which allowed the bullet to move side to side slightly (does that make sense) when it was pushed into the barrel. You can see the bevel at the bottom in this pic.

 

[diablo]

I had the exact same thing happen. What I figured out is the back of my bullet was beveled, but the bottom of my sabot was flat which allowed the bullet to move side to side slightly (does that make sense) when it was pushed into the barrel. You can see the bevel at the bottom in this pic.View attachment 119882

Yeah, bad idea shooting a boattail in a sabot made for flat-based bullets.

 

[muleyczy]

Yeah, bad idea shooting a boattail in a sabot made for flat-based bullets.

I’m following this but not certain I understand. Would you mind explaining further?

 

[Ballistic]

Long heavy bullets need 3 things to keep them from tumbling in a muzzy.

1- positive engagement into the riflings (obturation) -sometimes a wad helps this happen sooner and consistently.
2- correct faster twist rate.
3- speed - if they aren’t moving fast enough they will tumble.

A 600 grain bullet and extra speed are not a friendly combo to shoot.
Over stabilization of a bullet only has slight accuracy issues.
Under stabilization by too slow of twist or slow speed has a huge effect on accuracy
Creating key holing and tumbling.

I would shoot the bullets with the tumbling issue using a chrony or labradar to verify speeds. I would bet the tumbling rounds are probably slow. A tighter bullet fit -more powder- or a wad should fix the issue.

Sometimes 5-10 grains of booster powder like 3FG or 4FG ahead of your normal powder charge (take the 10 grains out of the normal) will do the trick better than a wad or more powder. It helps obturation happen sooner and seals the barrel for consistent speeds.

Knurling the bullet to make it a tad bigger (tighter down the barrel) could help as well but there’s an art to doing it well - and I think you can get the results you want without doing it.
As long as the bullet will seat onto the powder with 2 fingers pulling down the ramrod you should be fine.
If it’s dropping onto the powder without any effort (ramrod without your hand) then bullet fit is the culprit.
Best Wishes.

 

[Katoom]

Doesn’t anybody care about avoiding high pressure loads in muzzleloaders? You want him to go up to 105 grains with 10 being fine powders? Could you at least tell us what pressures you expect such a load would generate? If not, could you explain why muzzleloaders are exempt from worrying about them blowing up in your face? Not saying it would but, then, when would it in your opinion?

 

[Ballistic]

Doesn’t anybody care about avoiding high pressure loads in muzzleloaders? You want him to go up to 105 grains with 10 being fine powders? Could you at least tell us what pressures you expect such a load would generate? If not, could you explain why muzzleloaders are exempt from worrying about them blowing up in your face? Not saying it would but, then, when would it in your opinion?

If this is directed at my comments please re-read my post - especially this part -

“Sometimes 5-10 grains of booster powder like 3FG or 4FG ahead of your normal powder charge (take the 10 grains out of the normal) will do the trick.”


In addition -Tons of trace pressure data has been done on black powder and black powder substitutes. Even the hottest of load combos (.50 cal) produce less than 25,000 psi -which is safe for the weaker metal found on most muzzy barrels.
Generally speaking-10 grains by weight of black powder will raise speeds 75-100 fps and when adding on the upper end -will raise pressures approx 3,000 psi.
Most .50 cal get to a point of “the law of diminishing returns”
You add powder and then at some point speeds don’t increase anymore.
There are exceptions. Double load one and they will blow up. Heavy bullets with a really long barrel and large doses of powder - you definitely can get into trouble.

Bullet stabilization on long heavy bullets is paramount or they will tumble. You can increase the twist rate if you shoot them at slow speeds or increase the speed with a slower twist rate.

Do some research on blackout center fire for example. They shoot long heavy bullets at subsonic speeds. Barrel twists are 1-8 or faster or bullets will tumble (.300 blackout). The same bullets in .308 win need a 1-12 or 1-10 twist (velocities are much higher).

 

[diablo]

I’m following this but not certain I understand. Would you mind explaining further?

Sabots are made for either flat based bullets or boattailed bullets. So if you’re shooting a Barnes Spitfire TMZ as pictured above in post #14 (with a boattail) you need to shoot it in the factory supplied sabot or a sabot designed for a boattail like the Harvester sabot below. These sabots support the base of the bullet.

Crush Rib - High Pressure Sabots - 50 Caliber - Boattail Bullet (50 Pack)

The Harvester Muzzleloading patented Crush Rib Sabots are precision engineered and manufactured in the USA to exact specifications and offer superior accuracy. Patented by Harvester Muzzleloading Reduces Loading Friction Up to 50% Operates to Loading Specs of all Muzzleloaders Easy to Load...

harvestermuzzleloading.com