Post by bhwoodsman on Nov 22, 2011 9:07:41 GMT -8
From the forum announcement of new chamberings for the 450 Bushmaster and 458 SOCOM, a lot of folks were a bit shaken by the bullet diameter for the 450 and the crimp for this cartridge.
I've been reloading now for about 40 years. Seldom if ever buy loaded ammo. I still have both eyes and all my fingers. None of my firearms are damaged. I don't know everything about assembling or reloading ammo.
The 450 Bushmaster cartridge is based on a large rimless pistol case. It headspaces on the case mouth. No rim or shoulder for this very important task. Overall case length is critical. Too long and the case rim will be forced into the bullet when chambering greatly increasing pressure. Too short may result in at least misfires when the firing pin may not hit the primer properly and/or the case may stretch to the point of case head seperation. Maybe immediately or in subsequent firings.
A crimp is mandatory unless they are going to be loaded single shot. Even then a very light crimp may be beneficial to keep the loaded rounds at the right overall length while in their storage cases while in transport and in handling. The case mouth tension will dictate this. These are heavy bullets. A taper crimp is called for and I'm sure the better reloading dies use this form. If not, don't use the crimp in the bullet seating die. If you load or reload pistol ammo like I do, I use a taper crimp die for this task. Seat the bullets to the desired OAL with the bullet seating die and then crimp with the taper crimp die. Lightly. Gotta have enough case mouth to headspace.
Bullets. Yeah, I feel your pain. I shoot and load/reload a 45-70. I've got .458 bullets from 300 to 405 grains. You can get some pretty sweet deals on these in bulk and I don't get too snooty about who makes them. If they are jacketed and in my weight and budget range, I can use them. Sizing .458 to .452 is not so bad or technical. It is another step but can be done inexpensively. If you have ever cast and sized lead bullets you already know the drill. There is an inexpensive die out there that works real slick.
So you say there is no cannelure on the bullet for crimping. You may not need it. You can use a light taper crimp without it but a cannelure is best. There is a tool for that too. Once again inexpensive. And, once again another step adding to the chore of loading/reloading. To me it's a hobby to save some money but also to do it my way. Just like most of us and building and modifying ARs.
In any case, bone up on case preparation and reloading in general. Safety. Safety. Safety. Have fun. I know I will.
I'm really looking forward to loading this 450 Bushmaster. Got my dies and I already have all the other tools and a powder used for another cartridge. Sized some .458 300 grainers to .452. Just looking to BHW to kick out the barrels. Sure would like to have another source for a bolt.
I've been reloading now for about 40 years. Seldom if ever buy loaded ammo. I still have both eyes and all my fingers. None of my firearms are damaged. I don't know everything about assembling or reloading ammo.
The 450 Bushmaster cartridge is based on a large rimless pistol case. It headspaces on the case mouth. No rim or shoulder for this very important task. Overall case length is critical. Too long and the case rim will be forced into the bullet when chambering greatly increasing pressure. Too short may result in at least misfires when the firing pin may not hit the primer properly and/or the case may stretch to the point of case head seperation. Maybe immediately or in subsequent firings.
A crimp is mandatory unless they are going to be loaded single shot. Even then a very light crimp may be beneficial to keep the loaded rounds at the right overall length while in their storage cases while in transport and in handling. The case mouth tension will dictate this. These are heavy bullets. A taper crimp is called for and I'm sure the better reloading dies use this form. If not, don't use the crimp in the bullet seating die. If you load or reload pistol ammo like I do, I use a taper crimp die for this task. Seat the bullets to the desired OAL with the bullet seating die and then crimp with the taper crimp die. Lightly. Gotta have enough case mouth to headspace.
Bullets. Yeah, I feel your pain. I shoot and load/reload a 45-70. I've got .458 bullets from 300 to 405 grains. You can get some pretty sweet deals on these in bulk and I don't get too snooty about who makes them. If they are jacketed and in my weight and budget range, I can use them. Sizing .458 to .452 is not so bad or technical. It is another step but can be done inexpensively. If you have ever cast and sized lead bullets you already know the drill. There is an inexpensive die out there that works real slick.
So you say there is no cannelure on the bullet for crimping. You may not need it. You can use a light taper crimp without it but a cannelure is best. There is a tool for that too. Once again inexpensive. And, once again another step adding to the chore of loading/reloading. To me it's a hobby to save some money but also to do it my way. Just like most of us and building and modifying ARs.
In any case, bone up on case preparation and reloading in general. Safety. Safety. Safety. Have fun. I know I will.
I'm really looking forward to loading this 450 Bushmaster. Got my dies and I already have all the other tools and a powder used for another cartridge. Sized some .458 300 grainers to .452. Just looking to BHW to kick out the barrels. Sure would like to have another source for a bolt.