Alternate cases for forming 450 Bushmaster

[pitted bore]

T-
Your comments are appreciated. A couple of followup points:

[1]
The interest in the 7.5x55 is 99% speculation, but the subject of alternative brass is intriguing even if impractical. The conversion could be done in extremis if 450B brass vanished for some reason, but your list in the other thread shows there' s lots of easier alternatives like 284, 6.5-284, etc. Hoot and yourself are absolutely correct in stating that the conversion is a lot of time-consuming work.

It's hard to imaging a situation in which 450B brass would vanish, but 7.5x55 brass would be available. Even in the middle of this current drought some loaded 450B ammo and 6.5-284 Hornady brass is available.

I may finish the one 7.5x55 piece I started and fire it, just to say I did it and also to determine the amount of body swelling. I'm already playing with other cartridges that require forming and certainly don't want to add the 450B to the list. I cannot think that a 7.5x55 conversion would add anything more to the knowledge of 450B behavior than the 284 conversion; both have the same LR primer and the problem of a reaming the neck.

[2]
This question is for you particularly: Do you know why the extractor groove diameter tolerance is only one half that of the .284 parent case? Did you design it that way? Is it something Hornady and crew added when writing up the SAAMI specs? Or was it a typographical error that carried on into the SAAMI drawings and specifications?

It's not a big deal, but it makes the 450B unique among SAAMI approved cartridges, I think. Just wondering if there's a touch of magic there.

Thanks.
--Bob

[wildcatter]

T-
Your comments are appreciated. A couple of followup points:

[1]
The interest in the 7.5x55 is 99% speculation, but the subject of alternative brass is intriguing even if impractical. The conversion could be done in extremis if 450B brass vanished for some reason, but your list in the other thread shows there' s lots of easier alternatives like 284, 6.5-284, etc. Hoot and yourself are absolutely correct in stating that the conversion is a lot of time-consuming work.

It's hard to imaging a situation in which 450B brass would vanish, but 7.5x55 brass would be available. Even in the middle of this current drought some loaded 450B ammo and 6.5-284 Hornady brass is available.

I may finish the one 7.5x55 piece I started and fire it, just to say I did it and also to determine the amount of body swelling. I'm already playing with other cartridges that require forming and certainly don't want to add the 450B to the list. I cannot think that a 7.5x55 conversion would add anything more to the knowledge of 450B behavior than the 284 conversion; both have the same LR primer and the problem of a reaming the neck.

[2]
This question is for you particularly: Do you know why the extractor groove diameter tolerance is only one half that of the .284 parent case? Did you design it that way? Is it something Hornady and crew added when writing up the SAAMI specs? Or was it a typographical error that carried on into the SAAMI drawings and specifications?

It's not a big deal, but it makes the 450B unique among SAAMI approved cartridges, I think. Just wondering if there's a touch of magic there.

Thanks.
--Bob

Bad Bobber, I did not design it that way. In fact I wanted the rim to be more like the 45acp's or at least the original 284's. These other numbers you describe are the work of the lawyers and this is what happens when you let lawyers do the engineering.

The thought was they could strengthen the head/web, by going to small rifle primers and more meat in the extractor groove. The Tort, was the concern. Remember, at that time no body thought this would work and forget about my documented data and 100's of thousands of rounds fired, over about ten years. But this is still the Bad-Boy on the Block, don't ya think??

..t