So I finally got out to the range. Had the place to myself. It was nice. I fired 100 Berry's 124 grain copper plated out of my shiny new M&P9. 50 were HP and 50 RN. They were loaded 10 each with .1 grain increment charges of Win231. The HP's started @3.6 grns and ended @ 4.0. The RN @ 3.8 and ended @ 4.2. HP's were seated @1.060 +/- .004 and the RN @ 1.120 +/-.005. I chronographed each shot alternating 10 HP and 10 RN. I had no issues with the pistol functioning even on the lowest charges.

The average velocities
RN HP
923 925
945 924
970 973
988 988
995 1001

I wasn't shooting for accuracy, good thing since I haven't fired a pistol in over 40 years, but surprisingly the higher velocity HP's seemed more accurate than the RN. I found it interesting that the two load ranges lined up so closely despite the .2 grain powder difference for each corresponding load. That obviously is caused by the deeper seating of the HP's.

After shooting off my own hand loads I ran a box of Win White Box 115 FMJRN through. At 25 feet I was able to put a full 10 round magazine into a 4 inch circle. I know that is pretty sad but I was pleased and it confirmed the factory sighting of the pistol was good.

As an aside I did some chamber measurements with the two bullets. The RN were 1.229 to the lands and the HP 1.062. I checked my measurements several time. Based on the HP one I was on or very near the lands @1.060. My next load I will keep the powder charges the same and reduce the OAL to 1.055. Given the velocities I feel I am still well within safe limits.

nothing wrong with 4" at 25 feet, nothing at all, thats minute of mugger any day of the week!!!

Sounds like you're doing things right. Do remember that seating a bullet out more than the loading manual recommendation won't cause any real problems other than possible feeding issues, but seating deeper, even slightly, can raise pressures dramatically. Most people don't try to seat handgun bullets out to the lands, but seat for reliability. In most cases seating out farther than recommended will actually lower velocity since it lowers pressure. Experiment...there's always a sweet spot. And stay safe.

It was not my plan to seat so close to the lands. The fat profile of the bullet and the normal varation in OAL put me there. Before Seating deeper I wanted to see what velocities I was getting with the low and moderate powder charges. To get some jump I need to go for a shorter OAL. I am confident 1.055 should be safe. I will start with the same load series and watch what happens to velocities and check for pressure signs.

MacD wrote:

I haven't fired a pistol in over 40 years,

MacD, 40 years???? Why such a long dry spell?

Last time I handled a pistol was when I was in a militia regiment while I attended university. I won an area command shoot-off with the Browning 9mm but after that I went into an administrative position and just never had the inclination to get back at it until now.

MacD, enjoy it to the max!

REALLY REALLY watch it with 9mm and seating depth changes, esp with jacketed stuff. I use plated too...Xtreme brand though. Reminds me...gotta order some.

Nice group @ 7m too! If that action dont stop whatever it is buggin ya, dont come see me, I dont want yer problem!