9mm - Power Pistol load data

[jaybr]

I'm working up some loads for 9mm 124gr Hornady XTP's and have a few questions.

Both my Hornady and Lyman load books list 5.7gr of Power Pistol as max load. I've seen several postings much higher, and the Aliant website list max as 6.4gr.

Hornady load is specifically for XTP bullets

Lyman is for 124gr JHP

Aliant is for 124gr Speer Gold Dot JHP

I've read that the Speer bullets are plated, not jacketed, does that make a difference?

They all also list different OAL, Hornady being the shortest at 1.06

I would assume that the Hornady OAL is correct since it is for the XTP bullet, however I'm a little worried about loading as much as 6.2gr behind that load as I assume the pressure would be higher than say 1.1 OAL.

So far I've tried 5.7gr at 1.065 OAL, they shot fine and I got an avg of 1068 fps

Also tried 6.1 gr at 1.1 OAL with avg 1102 fps.

Both of these are below the listed book velocities but I fired from a longer barrel. Do chronographs vary much?

 

[Steve C]

Do chronographs vary much?

Chrono's don't varry much, different guns will, even with the same barrel length. Shooting on different days at different temperatures will varry your velocities somewhat too mut not much.

You should be observing your brass for obvious pressure signs like primer cratering, piercing, flow or flattening.

What are you trying to accomplish with your loads, a specific velocity or are you shooting for accuracy?

You only gained 37 fps with a .4 grain increase in powder, as long as there is no obvious pressure signs then increasing .1 grain to 6.2 isn't going to blow up your gun but again, check for pressure signs before proceeding any further or deciding to continue using that load.

 

[Jim Watson]

Chronographs don't vary much - although I heard of a dud last month - but the barrels used in lab tests don't have a lot in common with what comes on a mass produced gun. They are of minimum bore and chamber dimensions to develop the most pressure possible from a given load so there is a safety margin on what you put in a real gun. That also gives unrealistically high velocity in many cases.

A 124 at 1068 is right in there with what the original 9mm Lugers were doing in 1903. Unless you have a real application for hotter loads, why push it?

 

[jaybr]

What are you trying to accomplish with your loads, a specific velocity or are you shooting for accuracy?

I've got the bullets, and I have plenty of FMJ for plinking, so I thought I'd work up some SD loads with these. There is no magic number, but I was hoping to get 350 ft lbs energy, which would require 1130 fps.

The numbers I posted where from my Beretta 90-two, 4.9" barrel.

I also tested them in my CX4 with 16" barrel, and got:

5.7gr - 1252 fps
6.1gr - 1329 fps

So there zipping along pretty good in the longer barrel.

I haven't tested yet in my Kahr K9 with 3.5" barrel

 

[kart racer]

I have pushed some 124's very hard with power pistol.I've loaded maximum loads and over, testing at small intervals in my cz's.I don't recommend going over max published loads,but I do believe after experimenting there is some fudge factor.

Testing with new brass and zero 124 gr fmj,I was loading at 115 gr loads and had no problems-it was a stout load,probably +p+,and with the cz's you have to load shorter due to the short leade.