40 S&W Load Data Confusion

[Hartkopf]

Ok the data might not be confused but I am. Hodgdon’s data for 180gr XTPs w/Longshot:
The starting velocity with 6.5 grains is aprox 1000fps which is pretty close to the rated velocity of most factory ammo.

8grs @1159fps is faster than BuffaloBores +p ammo.

Hodgdon’s data for Berry’s bullets is a little milder but still way up there.

So what am I missing? I’m hunting for data with 180gr fmj and Longshot. These loads seem dangerous so I’m not doing anything until I understand what’s going on.

 

[WrongHanded]

Hornady says 4.8gr as a starting weight, and 7.5gr is max with their 180gr XTP or FMJ.

I didn't see Longshot in the Speer or Lyman manuals with a 180gr in .40S&W.

 

[twistytorn]

Well, the Hornady and Hodgdon data do overlap and they're based on the same case, primer, and OAL, so if you're looking for a reasonable load, it seems you could start somewhere in the Hornady data and see what you get for velocity. They used a 4.5" barrel Glock.

Otherwise Hodgdon is likely the best source of info on their data.

 

[Kevin Rohrer]

I use Longshot w/ 180gr bullets, and believe my loads use 7.0gr. Am not home to confirm it. The load is mild in my BHP and very controllable.

 

[sparkyv]

I'm using 180gr FPRN PC with LS right at the max Hodgdon data shown, 1.147" COAL in a 4"bbl M610 and getting 1176fps with no issues. I usually load a bit long in 40S&W, but within headspace of my CZ P-09 chamber which is the tightest I have. I save XTPs for my 10mms. For me, it's best to consult several sources for load data and work within the combined limits. I usually start in the range middle and work up.

 

[Walkalong]

8grs @1159fps is faster than BuffaloBores +p ammo.

That’s smoking with a 180. Jacketed 180s at 950/1000 FPS depending on barrel length is controllable and plenty to get the job done.
950 is my target velocity with the 4” barrel of my FNS-40.

I have chronoed a couple of factory 180 Gr JHP self defense type ammo and that’s about what they run in it.

Longshot can easily do that at safe pressures. Slightly faster powders can do it as well in fact

 

[Lennyjoe]

Hornady shows 7.5 gr of Longshot. I think I’m running 7.1 gr with Extreme 180’s with great accuracy out of a Walther PPQ, G23 and Baretta 96.

 

[GeoDudeFlorida]

So what am I missing?

I don't think you're missing anything I just think you're overlooking what you already know. That happens sometimes when people are looking at "data."
First off, BB uses a JHP bullet but not a Hornady XTP JHP bullet. Bullet profile and construction, gilding materials, core material, all of these factors in just the bullet can make a big difference in pressure and velocity. Second, differences that are tiny on a set of calipers but can be HUGE in a tight-spec' chamber or, as BB points out, an unsupported chamber. BB is selling loaded ammo (very high liability) while Hornady is selling bullets and Hodgdon's is selling powder - still substantial but much lower liability. As long as they can backup their data, Hodgdon's has some protection and I'm pretty sure they can backup their data.

You saw it all but it didn't make sense because the data is lacking context - different bullets, different testing methods, different assembly methods - and that's what gets confusing looking at different data sets.