I shot my Model 70 458 Win for the first time this afternoon. I was just out playing with it before I send it to become a 458 Lott. Shooting .458" 500 grain cast Meister bullets in front of 45 grains of XMP5744 and a Fed215M primer I was getting keyholes at 25 yards--I didn't think anything would ever keyhole in that short span! Thoughts, anyone?

Thanks,

[ 11-11-2002, 06:24: Message edited by: ACRecurve ]

Andy, I got pitiful accuracy not long ago from a 44 Magnum rifle shooting cast bullets. I solved it by getting bullets sized .431 rather than .429.

I am GUESSING you may have several things going against you. The bullets need to be oversized to get a good "grip," if you will, of the rifling. Secondly, your rifle may not like the 500 gr bullet....at least not at the velocity you were trying to drive them.

For sure something squirrelly was going on! Does the rifle shoot well with other bullets or loads? Whatever you were doing with this ammo today, your rifle clearly didn't like it! My guess is an oversized bullet would help more than anything. Note, I am recommending this ONLY with cast bullets.

If you know the gun will shoot with other things, I wouldn't lose any sleep over it. Hope something I said makes a little sense.

It probably hit one of those tumbleweed ass things flittin' around the desert.

Andy,
Only three things can cause keyholing.. oversized bore, undersized bullets, or way wrong twist. mic your bullets? Look at the bore?

This is the m70 we talked about, right? You might have to send to winchester and tell them it's broke. Might get the barrel right before you do the lott.

Or,
dang it all, call pacnor and get rolling

Best of luck
jeffe

I have a model 70 win 458 super grade, pre 64 rifle. Excellant shape. I inquired about the 454 lott, was told its not a magnum length action and the conversion could not be done. Is this true or not.

buford,
all pre-64 actions are the same length, it might require a little milling, that's it. From hornet to 300HH.
jeffe

I worked for three years trying to get my .458 77 Ruger to shoot lead without luck. Always keyholed at 25 yards. Bore slugged at .458 inch. Sized bullets from .457 to .461, weights from 400 to 525 gr., velocity from start to max. No change. We even worked out what weight bullet and velocity we needed for the twist. No luck. The one item I have no control over, and still get the bullets to work through the mag was overall length. My 77 has a throat about a mile long and there there is no way to seat the bullet out to the lands and still make it work through the mag. I even tried sizing the bullet to the throat; nope. This same rifle will shoot every jacketed bullet from 300 to 500 gr. into nice, tight one inch or less groups, but put a lead bullet down her bore and she shoots patterns. All the money I wasted trying to find cheaper bullets to shoot would have paid for a life-time supply of jacketed bullets. It took three years of frustration before I cut my losses and gave up on lead. Of all the rifles I shoot lead in, it's the only rifle I have come across that absolutely will not shoot lead, and with a barrel that shoots jacketed as well as it does, changing the barrel is not an option.

Buford,
You do realize,don't you,that your rifle is worth $3,000 or more?Do you realize that by rechambering it you'll be automaticaly making it into what collectors call a "shooter" and will be throwing most of it's value right out the window??

If I were you,I'd just keep her has a 458 Winnie and be happy.If you can't kill something with a 500 grain bullet going 2000 FPS,you're doing someting wrong.

I have had the same "keyholing" experience with two different .458 win mag rifles. I found that a .459 bullet cast from " Linotype" and lubricated with SPG solved the problem. Previous alloys while seemingly hard enough demonstrated some rifling patterns on recovered bullets that I concluded were due to the bullet metal being too soft and not properly being engraved by the rifling. The switch to Linotype completely solved the problem and resulted in 100 yrd groups of < 1.5 inches. I used a load of 28 grs of 2400 and a Dacron filler to case mouth and light compression by the bullet and a crimp. Try it!-Rob

I have had the exact same experience as Big Bore with shooting cast bullets in a 458 Winnie. My rifle was a M70 Winchester. It too had a Lllloooonnngggg throat. It would shoot lead at very low velocities, i.e. 1400 fps with decent accuracy i.e. 3" @ 100 yards. With 500 gr Hornady soft points over 69gr of IMR3031 would print 1.25" groups at 100 yards.

I had a home made M98 in 458 Winnie that had a somewhat shorter throat i.e. a custom reamer. This rifle would spit lead at around 1800 fps and maintain 3" groups at 100 yards. Bullet weight did not seem to matter nearly as much as velocity.

BRIAN it was just a idea, got caught up in that horsepower thing.Did not realize its worth $3000 plus ,found it in a pawn shop.

Paper patching might help those unstable .458 bullets too.

TSTURM - I know we aren't talking exactly the same thing, but I owned a .458 American for a couple of years and it LOVED cast bullets. In fact, that's about all I ever shot in it. I used a custom made 370gr HP. Very accurate. Very deadly.

Robgunbuilder,
Linotype with SPG lube, I would never have thought of that. I was told my Marshall Stanton over at Beartooth that SPG was primarily used for for its ability to decrease fouling in black powder rounds. I had ordered some .454 bullets with SPG and he called to see if that was what I really wanted, which it was not. He set me straight on that goof-up so I would never have looked at SPG for use in the .458, although I did try very hardcast and heat-treated bullets that went 26 on the hardness scale, of course with no luck. Just goes to show, what ever works...

Ross Seyfried did a lot of work trying to figure out rifled shotgun slugs, particularly in relation to the accuracy obtained by early express rifles and cast slugs.

What he learned was that there are about three differences between the rifles we used twenty years ago to shoot large cast bullets and the rifles that were used around a century ago. They were:

1) If you shoot a lead slug too fast, the rifling "strips", and doesn't rotate the slug. It just tears up the slug. If the twist is too fast (same thing, really), the rifling "strips" and just tears up the slug. This is why rifled barrels intended to shoot large lead slugs have slower rifling?

2)The rifling inside the barrel of those old rifles looks different. My recollection is that Seyfried described the lands as being wider and taller, and therefore more "strip" resistant?

3) "Gain twist" (rifling increases in rate from breech to muzzle) was more common in century-old rifles.

In short, the problem with shooting big-bore cast lead slugs fast down rifled barrels, is that great care has to be taken to accelerate the spin slowly or not too much at once (use slower twist, see BP muzzleloader twists), because there is not enough area on the outside of the slug where the twist is applied to spin up the massive slug that fast.

It's been perhaps fifteen years or more since I read those articles, and these are vague recollections. I wouldn't want to offer the statements above as things that I am absolutely sure Ross Seyfried wrote. Instead, consider them as discussion starters.