Sig M17 and m1152 ammo

This week, I have done a lot of shooting here at ft campbell with the team members that are going to All-Army at Ft Benning and have found some odd characteristics with the M17 and standard issue m1152 (115gr fmj flat point) ammunition combination. We shot about 1800 rounds between 4 guys out of several pistols so pretty solid trends.

Recoil is very snappy. This is +P+ 115gr, going 1350ish fps, so it has quite a punch. Significant muzzle climb over the 147gr ammo. But here's the weird thing, it printed about 8" low from point of aim @50yds from all our guns. At 25 yds, it was about 4" low. I don't think there is any bullet drop at that range, I think it is just how Sig set the sights up and how the bullets are interacting with the 1:10 twist barrel. Accuracy was acceptable, I would guess around 3" at 50 which is great for a combat gun. The entire team was able to ring steel at 200yds in wind with ease by holding high.

At short ranges (7-10 yards) which would be more normal 'combat' distances, you have to put the front sight post well above the target and completely obscure it. Fine for people, neck holds are effective, but a huge PITA shooting small round poppers or steel targets (which we will be doing at the Small Arms Championship next week). 

I have a personal m17 at home, and have found it to shoot poa/poi as expected with 147gr. So this is either a function of this red hot 115gr special ball, or some weird sight setup they have done for the Army. I bet this ammo would really smoke through a 1:32 barrel, but personally I preferred the old m882 for training. Maybe we will get lucky and be issued the subsonic m1153 round and see a higher POI.

Shooting low with hot, light bullets is expected. The bullet exits the barrel before the muzzle is at full recoil while the 147 bullet being much slower stays in the barrel longer while the muzzle is rising.

Sure, agreed... but this ammo was adopted specifically for this pistol, and it is what is issued/shot with the m17 99% of the time. m1153 is used/issued rarely. So why would the sights be that far off is my question.. seems like a big oversight for such an accurate pistol.

M882 ammo is 124 grain not 147.