Different pistol powder resulting in significant POI?

[prickett]

I've been shooting Titegroup, then WSF in my 9mm. With the great powder drought, I've had to dip into my shotgun powder (Titewad). It is a VERY soft shooting powder, barely able to cycle the slide at max powder.

Shooting the new load, my shots all seem to hit about 6" to the left. It seems very strange to me that changing powders would result in such a significant difference in POI.

Is this behavior something anyone else has seen?

[JRPVT]

prickett, yes it's sort of normal behavior when you change powders or boolit weight. We have also been trying different powder/bullet/boolit combos, and frankly, we will have to adjust to the pure physics of each load. Given a ransom rest and a lot of range time, you could plot it all out. Essentially, the slower, softer shooting powders have more dwell time in the handgun. All of the variables come to play then, sort of like shooting a flintlock, everything needs to stay in place until recoil kicks in. Long dwell between squeezing the trigger and a muzzle flash. Same the other way, faster, sharper powders/lighter bullets can bring your poi up/ or down; depending on if you predict recoil and hold "down" on your pistol to prevent excessive muzzle flip. Left and right movement is usually grip/ trigger pull related. Also depends on left/right rifling. Tons of factors in play. Sorry to be so long winded, but find one you can live with and tweak your shooting style to it.

Best of luck, Dave

[bowenrd]

When you have a pistol or revolver with fixed sights using different loads is one way of getting it to shoot to point of aim.

When you change one thing you change everything, results anyway.

[tazman]

I had the same issue using Titewad except for very light boolits. For boolit weights under 110 grains I use Titewad exclusively.
When I use it just for the light boolits, I get the same POI as the other powders with the heavier boolits.
If I use the normal powders for the light boolits the pistol sprays boolits everywhere.

[prickett]

I'm used to high/low changes in POI, but this is the first time I've seen left/right changes to POI. It does sound like it could be a grip issue as I'm using a new pistol too. But I switched back to "old faithful" and saw the same results with it.

[lwknight]

I submit the possibility of knowing that the powder is not first choice, you may be subconsciously gripping tighter to prevent stovepiping. Thus, changing your poi laterally.

[Blackwater]

Here's another possibility to consider: You don't say so, but I'm assuming you're shooting a double stack 9. These guns usually have a pretty wide grip frame in order to accomodate those wide bodied mags. This makes the shooter with average sized hands have to sort of reach around to the right side of the grip (for a right hand shooter) to grip the gun. This thereby puts the hand to the right, and handguns always recoil away from any fixed pivot point (our wrists) if it's to one side or the other. Old handgun techniques called for the gun to be gripped so that the centerline of the bore and the long bones of the forearm were directly in line with each other. If one's hands just aren't big enough to accomplish that, and still reach the trigger with the trigger finger, there's no option left but to compromise one's grip and grip it around to the side. This is often what causes guns to shoot to the left for right handers (expecially single actions) and to the right for left handers.

When guns were originally designed, there was concern about holding on to them no matter what. Horses were the mode of transportation, and they could be ornery and unpredictable sometimes, so the manufacturers designed in a taper outward to the bottom of the grips so that keeping them in hand would be surer and more secure. That solved one problem, but left us with another: due to the fact we get used to something being made a certain way, and the fact that we tend to automatically distrust something that violates traditional design, we've tended to continue making grips that way. However, in more recent times, custom grip makers have made custom and production grips that taper DOWN toward the bottom rather than outward, and these enhance double action trigger pulls in revolvers. In autos, though, this ability is severely limited by the shape of the grip frame which is necessary to accomodate the magazines, so there's little that can be done. However, there are SOME grips that help considerably, even though the dimensional shifts are relatively small. I recall one set of grips from Cheaper Than Dirt that a buddy had on his P-35 Browning that was subtly but VERY effectively contoured, and to grip the gun while wearing these was truly a revelation. The P-35 is a great gun, to be sure, but it's never felt "right" in my hands until I felt my buddy's gun with those grips. They extended forward and back on the grips just a tad, but it was enough, with the changes in taper and girth down the length of the grip, to make an awesome difference in how it felt in my hands. It was just a very small amount thinner where the trigger finger and thumb wrap around the grip frame, but ovaline in contour, and just flat felt "RIGHT." The difference WAS indeed GREAT, too. When I gripped the gun, I tended to grab it more exactly in the same place in my hand, and this increased consistency in my shooting - not a small thing, but one that many frequently don't notice today.

Whenever I find someone having lateral dispersion, I usually suspect the grip first. It's not always the right answer, but it is in the majority of cases, or at least is ONE of the root causes of lateral problems. FWIW.

[Echo]

A Big Plus One for ^^^^

[prickett]

Whenever I find someone having lateral dispersion, I usually suspect the grip first. It's not always the right answer, but it is in the majority of cases, or at least is ONE of the root causes of lateral problems. FWIW.

The grip very well may be the issue, but my pistols both have smallish grips (a CZ-75B and an M&P 9mm Pro with the smallest palm swells). I have average sized hands and both guns feel good in my hands. My curiosity is that I've shot the CZ for years, and just now does it exhibit this behavior. The M&P is new, so I don't know what to expect with it.

I guess the next step would be to shoot off a rest to determine if it is me or the gun/ammo.

Thanks for the suggestions, all.