Practice Ammo

[Qtiphky]

Does point on impact really change that much at normal confrontational distances between ammo types/bullet weights? Meaning, I carry 147 gr Hydrashocks in my 9mm for SD purposes, but I practice with 115 grns FMJ's at 25-30 feet. I also shoot different bullet weights and types in my 10mm, 40 and 380. Does the point of impact change enough to matter at these short distances?

[cornbush]

It can be a fairly big difference sometimes.
My uncles 92f changes POI about 16 inches going from 115 to 147 gr pills.
My .357 changes very little.
My .45 changes about 3 inches from 185's to 200's and about another inch when I go up to 230's.

[kraigwy]

impact has more to do with bullet weight in a pistol then it does velocity. Heavier bullet will recoil more, causing them to impact higher.

Fix sight guns are designed for a certain (most common) bullet weight, I.E. 38 are designed to shoot a 158 grn bullet, so of course lighter bullets are going to shoot higher generaly.

GENERALY, the could be exceptions.

I try to match my practice ammo to my carry ammo, its easy for me since I cast dern near everything.

For example, for my 642 (and my other 38/357s) I usre 148 grn WCs for practice. My carry bulle is a 150 grn SWC (Lyman 348477) They pretty much impact the same place.

[Brian Pfleuger]

Self defense shot distances average about 7 feet and almost never exceed 20-something. At those distances, very little matters except your composure.

[Unclenick]

The heavier bullets recoil more, but go slower, for any given powder charge. They spend more time in the barrel while it is recoiling upward. Thus, they exit at higher angles of barrel elevation than lighter weight bullets over the same powder charge. Increased powder charge also causes more recoil, but it also speeds the bullet up, so it exits the barrel sooner. The net result is that the angle of barrel elevation elevation at bullet exit is changed relatively modestly by the charge increase. That's why bullet weight, rather than charge, affects short range (up to 25 yards or so) pistol point of impact (POI) most. Rifles don't always follow this rule because barrel whipping can sometimes overwhelm recoil elevation in them. But for the shorter barrels in most pistols, this rule seems to hold.

How much effect there is on POI depends on both range and that final angle of barrel elevation. A light gun or a gun with a barrel line high above the grip frame will elevate more in recoil than a heavier gun or than a gun with a lower barrel line. It's just the vector physics of the recoil direction and the mass inertia involved.

A friend of mine got a Ruger Alaskan in the .454 Casull cartridge. That cartridge elevated the muzzle of that 2.5" gun so much that the rear sight could not be set low enough to avoid a high POI with 300 grain bullets. The frame and rear sight want a longer, heavier barrel. I think we were about a foot high 10 yards. A bit too much for best comfort, so a taller front sight insert was needed.

Where this POI issue could make a difference in SD shooting would be in employing the Mozambique drill or other emergency head shot practice. For center of mass hits, it shouldn't be a problem at the usual distances. I've often set or filed sights to be close to spot on with a somewhat light bullet, then used a 6:00 hold on a paper bullseye with heavier bullets. 200 and 240 grain bullets in .44 Special in my 3" Bulldog, for example. Just as long as I know where the bullet hits, I'm OK.

Despite the short distances normal for SD, Gunsite taught us that you keep the range as long as you possibly can in a gunfight because you are the better trained shot. No point in spotting the BG an equalizing factor if you don't have to. There's not a lot to choose at mugging range, but in clearing your house after hearing a bump in the night, you have some choice in the vantage point you look into a room from. I find accuracy capability beyond what is required also offers a psychological advantage. Excessive precision may not help, but it doesn't hurt anything. The reverse isn't always true.

[l98ster]

Peezakilla is right on the money!! At SD distances, every gun out there is "accurate" enough. The reason you become "innacurate" is because someone is shooting at you!!! Keeping composure is the hardest part, not only because you are in a life threatening situation, but also because there there is no real way to practice that situation (nor would you want to).

Imagine a range that shoots back at you!!!

Come to think of it, I saw a show on the outdoor network (cant remember which one), but there was a tactical range where the targets would actually shoot paintballs back at you. Obviously you needed to wear a facemask and goggles but this is the most realistic way of practicing self defense that I have ever seen!!

-George

[bobelk99]

Grandma said "Tain't no sech thing as 'Accurate enough'"

Make sure your POI is set for whatever you carry, not what you use at the range. Better still, use same load for all.

I realize nearly everybody but me buys special SD ammo for a carry gun.

I am an 'old geezer'. I have a few times seen what two or three rounds of 45 ball does to the human body. If ball won't stop the BD I'm in deep dodo.