.357 Mag with H110/296 and 180 gr XTP

[OlympicViking]

I'm going to load some .357 Mag with XTPs over H110 for my 686+, but I'm finding inconsistent data. The first place I looked was Hodgdon's website. Hodgdon only has 180 gr data for the Nosler Partition, but they seat it to 1.575" and the powder range is 13.0 – 13.5 gr. I checked my Hornady 9th ed manual and they list a COAL of 1.590" and a range of 11.3 – 13.1 gr for the HP XTP. Lastly, I checked my Lyman 49th ed and they list a COAL of 1.585" and a range of 13.9 – 14.5 gr for an unspecified 180 gr JHP.

What data would you guys use? I know the minimum for H110 loads should only be 3% less than the maximum charge in order to avoid dangerous pressure spikes, so the powder charges listed in the Hornady manual seem downright unsafe to me. My COAL will be 1.590" because that places the lower of the two cannelures right at the case mouth for that hearty roll crimp that H110 needs. I'm guessing Lyman isn't printing data that's blowing up folks' guns, and their COAL is closer to mine, so I'm leaning towards their starting charge weight over Hodgdon's.

 

[Steve C]

The data from the maker of the bullet is usually the best data to use as it was developed for the specific bullet you are loading. I would reduce the max Hornady data by 3% for a start load of 12.7gr and work up to 13.1gr max. Remember to crimp tight and use magnum primers. COAL is usually set by the location of the crimp groove in jacketed bullets.

 

[LoonWulf]

Im loading for a rossi92. I used the 13.5grn suggested by hodgdon and it produced almost exactly the predicted velocity. Pressure seems pretty sedate, im inclined to continue from there.
Ive seen a few references to the 14.5grn loading, as well. This may have been droped for fear of someone getting them into weaker guns, a change in the powders burn characteristics, or that the load was simply to abusive to the average .357...or none of the above.

 

[buck460XVR]

Revolver JHPs have different profiles and bearing surfaces. Their OAL, unlike with pistol bullets is determined by the cannelure and cannot be adjusted if one crimps where they are supposed to. The profile many times determines where the cannelure is and this also determines how much bullet is inside the case, thus affecting case volume. This is why I always suggest using recipes that use the same bullets first. No interpolation needed. As for the Hornady loads being unsafe, they have been tested, proven safe and are published. You really think Hornady would open themselves up to liability by publishing unsafe data and then charging for it? Use a magnum primer with H110/W296 and a firm crimp and you will be fine, even at the start levels. altho they probably will not be the most accurate. I would start @ 13 and work up. BTW.....Lyman is not using an unspecified bullet, but the 180 gr XTP.

 

[ArchAngelCD]

I'm sure the difference in OAL in each source us during to different bullets being used. The data is different probably due to different testing equipment and powder lot numbers. This is why data is given in ranges so it will be safe in your gun with your bullet. It's why we start low and work up, to allow for slight differences in guns and components.

I have loaded 180gr Hornady XTP bullets for the.357 Magnum and used W296/H110 and Lil'Gun. I used the data on the Hodgdon site with no signs of over pressure. Note, I only use Lil'Gun in ammo shot in my levergun.

 

[Varminterror]

I'm going to load some .357 Mag with XTPs over H110 for my 686+, but I'm finding inconsistent data. The first place I looked was Hodgdon's website. Hodgdon only has 180 gr data for the Nosler Partition

Nothing inconsistent about what I'm seeing. Data for the 180 Partition isn't data for the 180 XTP. It's that simple.

The Partition is a very specific bullet design, as is the XTP - neither are good candidates for use with generic load data, and the XTP especially should only use data published using the XTP. Use the Hornady data.

 

[.308 Norma]

The Partition is a very specific bullet design, as is the XTP - neither are good candidates for use with generic load data, and the XTP especially should only use data published using the XTP. Use the Hornady data.

I'll second that.

 

[OlympicViking]

Update: I emailed Hodgdon last night when I posted this thread asking about XTPs and H110. I checked my email when I got home from work today, and Hodgdon gave me Hornady's data.

 

[murf]

Apparently, you guys give good advise!

murf