Last night, I reloaded 500 rounds of 9mm. The recipe was 115gr xtreme bullet, 4.2 gr of titegroup, 1.1" oal. I have it written down that I liked this load before (but with berrys).

I went out back today with my G17, and found that my point of impact was roughly 5" high at 70ish feet. I was perplexed and even shot from a rest to confirm that it wasn't me just having a bad day. What gives?

Also, I was shooting with a wml attached, which I do not typically do. In the past, the gen5 g17 has had laser accuracy.

Well, changing bullets and loading in quantity is never a good plan. They ARE a bit different in construction and response to pressure results in POI differences. Possibly the new load is a bit slower, powder charge needs adjustment and in OAL. I have had similar results when changing bullets and had to adjust OAL and powder charge to get the desired POI vs POA. Start by removing the light and retest.

A slower bullet would shoot higher.

quote:

A slower bullet would shoot higher.

Well a heavier bullet will often shoot higher, not just slower bullet. Easy to test, run some 115gr @ 1000fps & 147gr @ 1000fps, get back to us.