[bernie]

The 180 gr. XTP's I reload for my .357 have two crimping grooves on them and I have always used the highest crimping groove in my .357 cases. What is the second, lower crimping goove for? I wondered if it was to load them in .38 special cases and keep them the same length. If this is the case, has anyone here actually done it and what were your results?

[earlthegoat2]

With the 180 gr XTP SPECIFICALLY the dual cannelures are for the use with 357 magnum and 357 maximum loadings.

Some say the rear cannelure is for controlled expansion, not a crimping groove. I always thought expansion was from the design of the hollow point in the XTP bullet though.

I am about 99% sure it has to do with both 357 Mag and 357 Max loadings though.

[jw johnson]

I was told they were controlled expansion. I load 357 maximum and use the forward crimp groove or it would not chamber in my revolver. (they would be too long)

Accurate bullet though.

[pbslinger]

I emailed Hornady and they told me the second cannalure is for the 351 Casull. The second one on the 300 grain .429 bullet is for the Dan Wesson 445 Supermag. The second one on the 300 grain 45 bullet is for the 454 Casull.