XTP vs. JHP data

[korny351]

Wanting to reload ZERO 125 gr. JHP in .357 Magnum. Looking through my manuals I am finding different specs for Hornady XTP than other JHP. The XTP's data starts at the max loading for other jacketed bullets. Speer recommends 18.0 to 20.0 gr. of H110 with their Unicore and Gold Dot 125's. Hodgdon lists only XTP over 22.0 gr. of H110. Lee has headings for both 125 gr. jacketed and 125 gr. XTP's with different data. Any explanation for this discrepancy? Just curious.

John K.

 

[rcmodel]

Unicore & Gold-Dots are plated-jacket bullets.

The XTP is a conventional cup & core jacketed bullet and is harder and maybe won't slug up as tight in the bore.

The XTP bullet shape also results in less bearing surface (friction) then more rounded profile bullets.

rc

 

[buck460XVR]

The Hornady manual lists a starting load of 17.4 of H110 and a max of 19.9 under their 125grn. XTP, which is very close to the Speer loads. Speer also lists their loads for their GDs the same as their standard JSPs and JHPs. Altho I don't load 125s, I load 158XTPs and 158GDs with the same load, and get similar performance.

Hodgdon lists only XTP over 22.0 gr. of H110.

I have found several of Hodgdons starting loads to be way too hot for my handguns to shoot, and many times way over the max loads listed in other manuals. One of the reasons I use more than one reference before trying something new.

 

[korny351]

Buck, as referenced in my initial post, the Hodgdon data is a max load. It is the only spec given and Hodgdon states that loads should be reduced by 10% for starting loads where no starting loads are published. But, your right, as the resulting starting load pretty much matched max loads in the Speer catalog.