Anybody seen this before? 250 gr SSTS of different length

[Rifleman]

Has anybody seen this before? Both seem to be Hornady SSTs. I weighed and measured both. Both are .452 in diameter and both weigh 250 grains. The only thing I can figure out is one has a much larger hollow area inside. Just wondering if anyone could tell me what is going on here. I wonder is one possibly a version Hornady made for T/C?[img src="https://i.imgur.com/yd4ByYj.jpg" src="" alt=" "][img src="i.imgur.com/yd4ByYj.jpg" src="" alt=" "]

[ronc]

All copper bullet...?

[ET]

I suspect the longer bullet is actually a 250gr Monoflex bullet.
www.hornady.com/muzzleloading/monoflex-ml#!/

[ported45]

The one on the right is the new style MonoFlex.

[ported45]

The one on the right is the new style MonoFlex.

[Rifleman]

Thanks, guys, yes The long one is the all-alloy Monoflex and the short one is the original SST. Appreciate the help!