Colorado:

I've never heard of anyone doing that. I can see how it might be an interesting project.

One thought though. The .450 No. 2 has a smaller base diameter than the .500 3 1/4" NE, .565" vs .573". So you gain .25" in length but lose a tad in diameter by using the .450 No. 2 case. The .475 No. 2 NE is also 3.5", but has a base diameter of .580", so it would be a better starting point than the .450. Also, keep in mind that the .250" longer case of .500 3 1/4" NE only saved a half ton of pressure over the 3" and they used the same load.
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