Hi fellas,

I just bought my first big bore (CZ 550 Safari Magnum) in 458 Lott.....I have been reloading for many years but never for a big bore. Do I have to crimp ? and how do I grimp ? I have never needed to crimp my ammo so far so every help is much appreciated. And finally.....do I need to buy a special crimping die or ????

So a search for crimps, crimping, 458 Lott in the Big Bore and Reloading links...there's a ton of information on both.

Be sure the cases are trimmed evenly...follow the seating die instructions, use a Lee factory crimper or buy a taper crimper...work slow and test.

Luck

If you plan on loading more than one round in the gun at a time you need to crimp. Otherwise the bullets in the magazine can move under recoil. I've only actually had this problem with magnum revolvers where the bullets are pulled out of the cases and jam the cylinder.

Crimping is pretty easy though. Most 458 bullets have a crimping groove. Just seat the bullets to the point where the case is lined up with the groove. Your bullet seating dies should have a crimp built into them. After you get the bullets seated to the right depth back off the bullet seating adjustment and then screw down the die until you feel it touch the case. Then slowly adjust down until you can see the brass being formed into the groove in the bullet.

quote:

If you plan on loading more than one round in the gun at a time you need to crimp. Otherwise the bullets in the magazine can move under recoil.

In over 30 years, I've never had this problem.

The only thing I crimp is revolvers, and even then, I only use a light crimp.

quote:

Originally posted by Ingvar J. Kristjansson:
Hi fellas,

I just bought my first big bore (CZ 550 Safari Magnum) in 458 Lott.....I have been reloading for many years but never for a big bore. Do I have to crimp ? and how do I grimp ? I have never needed to crimp my ammo so far so every help is much appreciated. And finally.....do I need to buy a special crimping die or ????

I also have a CZ 550 Ssfari Magnum in 458 Lott AND I crimp. Any bullet seating die you buy for a 458 Lott will have a crimping function built into it and setup is fairly easy.

1. First, seat a bullet until the mouth of the case is in about the middle of a cannelure or groove.

2. Then back out the seating stem following which you will screw the die in until you start feeling resistance when ramming a case up into it. The resistance you feel is the crimping of the case.

3. Screw the die in until you have a satisfactory crimp

4. Then, with the cartridge in the die, screw the seating stem back down firmly. Your die is now set up to seat and crimp a bullet with one operation of the ram.

Some prefer to crimp in a separate operation but I don't with my 458 Lott loads. A Lee Factory Crimp Die is another excellent way to crimp but I think you would have to have it custom made and it might have to be built in one of their larger die sets which would require a larger press.

As far as bullets moving in the magazine under recoil; I don't know regarding the 458 Lott since I've always crimped bullets in cartridges to be fired in that gun but I know for a fact that without a crimp, bullets in my 378 Weatherby Magnum get rammed into the cases. Also try a "light crimp" in full house 460 S&W Magnum cartridges to be fired in a revolver and you'll have a big surprise.

By the way, I've never had to trim 458 Lott cases to get a satisfactory crimp but then my cases are all of the same brand. If you need to trim, I'd suggest a trim die since they're fairly cheap, work well and are fast enough since the number of cartridge you'll load will probably be relatively small.

Grumpy:

I've had the rounds move under recoil in a rifle, but never the bullet. Good to know the .378 is a little different.

The largest revolver I've loaded for is full house .44 Mag. If I'm ever fortunate enough to load for the .460 S&W, I think I'll take your advice and use a firmer crimp. Thanks for you insights.

+1 to Grumulkin on crimping procedure. It is necessary to at least check case lengths, as the seater die crimp won't be consistent if length varies.

The alternative is the Lee Factory Crimp die, which will work with varying case lengths. For the .458 Lott, it should be available as a stock line through Midway's European branches [Sweden and Norway list it], Product # 120512.

Direct from Lee, it's a custom order item.