40 S&W X-TREME Bullets

[gk3]

I have 500 of these to load: 10/40 180gr HP copper plated. Not exactly my first choice, but a friend got out of reloading and sold me a box for a price I could not refuse. I'm looking for a place to start with load data and have a question.

I'm currently using HP-38. The Lyman 49th ed. has a 180gr JHP load for W231 starting at 5.0gr up to 5.6gr ( 927 - 1015 fps and 1.115 COL). Hodgdon's site shows an XTP 180gr at 4.1 up to 5.0gr, advertised at 797-947 fps with 1.125 COL. This is the closest match I have for these projectiles, and the only experience I have with 40S&W is 180gr TCFP and FP projectiles.

I would have thought the XTP and JHP rounds would be more similar in powder charge. I'm trying to understand why that's not the case. I'm not so much looking for load data as I am information on the best place to start. Should I load a few small batches on the low end of what's listed for the XTP 4.1 - 4.3 and see where they're at? I do own a chrono.

My goal is to make these meet power factor for USPSA. Has anyone ever worked with these projectiles and HP38 before?

 

[[email protected]]

In general the XTP bullets are longer so there is more bullet in the case when seated at the 1.125 COL. This gives less case capacity so you use a lighter powder charge. The velocity difference can be a result of the type of action used to collect the data. For example an "universal" receiver with a "x" length barrel vs a actual gun with "x" length barrel.
You seem to be on the right tract by starting low and working up. Hodgdon lists the 180 grain Berry bullet which is similarly constructed as the xtremes. They show 4.4 to 5.1 grain charges for the berry's

 

[Hondo 60]

I would have thought the XTP and JHP rounds would be more similar in powder charge.

XTP is a jacketed hollow point
The Xtreme bullets are plated, not jacketed.
========================================================
The difference between the published data is in what the ballistician (& lawyers) felt comfortable with.

 

[Walkalong]

I loaded some of those X-Treme 180 Gr HPs with 5.0 Grs of old (metal can) W-231 at 1.130 to 1.135 OAL and they gave an average 932 FPS from a 3.85" Baby Eagle, were accurate to very accurate and had a nice recoil impulse.

I loaded some old style Precision 180 Gr coated bullets with 5.0 Grs of old (metal can) W-231 at 1.125 OAL and they gave an average 967 FPS from a 3.85" Baby Eagle, were very accurate and had a nice short recoil impulse.

 

[gk3]

Correct, they are plated. I was referring to the variance between JHP load data in the Lyman manual vs XTP on Hodgdon's site, but I think eam3clm is correct that the XTP is longer and therefore seated deeper at the same OAL I just don't have any XTPs for comparison.

 

[gk3]

Thanks, Walkalong, that's very helpful.

 

[ray15]

As you've seen in the load data, not all JHP are created equal. The exact finished diameter, the thickness and hardness of the jacket, the jacket material, and the hardness of the core can all substantially influence the charge weight required to make a given pressure/velocity level. For instance Nosler JHPs often require 10% more charge than something like an XTP.

I've found the xtreme plated hollowpoints act a lot like XTPs where charge weight/velocity are concerned, as Walkalong's data confirms.