[coy1369]

Went to the range yesterday with some ammo and the 24/7 pro 45acp. I started out shooting at 25 yards at paper. I was using a pistol rest. I wanted to check the "point of aim" to see exactly what the point of impact was. I loaded a mag, settled in and shot a ten round group. I was holding the sights "dead on" and not using a 6 o'clock hold. The pistol shot pretty much on center. I loaded another mag, using the same hold, and again, shot on center. After I was satisfied how it was shooting, I switched to shooting steel off hand. I have a nice spinning target with a 6" and 8" paddles on it. After a few mags I began to miss the steel targets and the more I shot the more I missed. I began to wander what was going on. So I switched back to the rest and paper. To my amazement, the pistol was shooting about 5" low using the same "hold" that I was using to start with. By now the pistol was very dirty and very hot. And I mean real hot. By now I've shot about 150 rnds pausing only to reload magazines. Idealy the thing to do now would be to let the pistol cool down and maybe wipe out the internals some but I was just about out of ammo.
Has anyone else notice a "shift in point of impact" like this. I know that when steel gets hot it has to expand and this could in theory change how the pistol locks up and thus change the point of impact. By the way, the pistol function flawlessly.

 

[jwc007]

Nope, never had that issue with either of my 24/7's (Pro 9mm and .45 OSS). Both went thru 300 rounds in one afternoon without changes to zero. However, this was done with the 9mm 24/7 at an indoor range in February, and it was a bit chilly up here. Probably about 60 degrees F indoors. For my .45 24/7 OSS, this was done about 3 weeks ago, at the same indoor range, and temperatures were a nice moderate 70 degrees F. I also use the dead on hold for most of my handgun shooting. I was shooting a Plate Rack of Pie Plate size Steel plates (30 feet) and IPSC Targets (15 to 20 feet), but I also shot some regular NRA Bullseye Paper Targets at 50 feet.

 

[Vismin]

Yeah, Coy, when I get tired my accuracy goes down too..nothing to be ashamed of. Just kidding.

I have sometimes suspected a similar thing, but I haven't shot with a rest in order to fully test it. Knowing how metal expands, you'd think theoretically it might affect accuracy. But I'd imagine the metals they use in guns are designed to prevent that. I will pay better attention to it when I go shooting next.

 

[Qwiks draw]

http://www.taurusarmed.net/forums/index.php?topic=6717.0
http://www.taurusarmed.net/forums/index.php?topic=6716.0
http://www.taurusarmed.net/forums/index.php?topic=1861.msg13596#msg13596
http://www.taurusarmed.net/forums/index.php?topic=2272.msg17734#msg17734
http://www.taurusarmed.net/forums/index.php?topic=7092.msg66642#msg66642
http://www.taurusarmed.net/forums/index.php?topic=7218.msg68075#msg68075
http://www.taurusarmed.net/forums/index.php?topic=7093.msg67050#msg67050
http://www.taurusarmed.net/forums/index.php?topic=3266.msg25295#msg25295
http://www.taurusarmed.net/forums/index.php?topic=1590.msg18607#msg18607

Have to agree with NYPD on this.
There are just too many variables that can be caused by humans rather then the mechancial contrivance.

Those are all in there and how to overcome those variables.

Type of grip,how the gun is gripped, how much pressure,trigger pull pressure, fatigue or lack of it,,follow through with the trigger and the shot, as well as too many other vageries ot list are usually the cause, or as a combination of factors that factor into all this.

Bullet weight, condition of the gun (dirty or not) can factor in as well, but don't normally factor in to POI changes that much. Never seen it in over 20 years of shooting. That includes observing many others who were shoooting as well over the decades.

This isn't a full auto weapon or high velocity varmint rifle or a blackpowder arm where that kind of thing can happen. Just isn't a factor.

Things do change. LOL

 

[James41]

Yeah, Coy, when I get tired my accuracy goes down too..nothing to be ashamed of. Just kidding.

I have sometimes suspected a similar thing, but I haven't shot with a rest in order to fully test it. Knowing how metal expands, you'd think theoretically it might affect accuracy. But I'd imagine the metals they use in guns are designed to prevent that. I will pay better attention to it when I go shooting next.

Yes metal does expand, that is why a bull barrel will usually hold better on a target when doing a lot of shooting than a thin "sporting" barrel will.

I used to have a Weatherby 300 mag that i loved. It had the sporting barrel to reduce the weight. On the first shot it was dead on. Following up with a second shot was real close on the first one, but quickly following up with a third shot you could see the difference. That is why when target shooting i would pull the bolt and run a patch through while letting the gun cool before shooting again.

I would expect that with a pistol being fired in rapid fire you would indeed run into that same kind of thing. I know that with my AR15 rapid fire by the time i get number 30 out the end of the barrel the accuracy is not as good as round 1 to 5 is...

 

[Trzeci98]

mine shoots low and to the right when she heats up

 

[coy1369]

Qwiks Draw, I'm the first to admit that human error would be the first thing to come to mind, thats why I got the pistol rest back out and did a slow fire. I haven't seen anything like this in 26 years of shooting out of a pistol either. I even came home and broke out the dial caliper and according to my measurments and some simple math I determined that the barrel wall thickness on the taurus, compared to my springfield loaded model,is about 10 thousanths thinner. the taurus is about .0055 and the SA is about .0065 measured about an inch from the muzzle. Next time out to the range I intend to try to duplicate this phenomenon. It's really no big deal I guess because this is a defensive pistol and if I ever got in a shoot-out that took more than a couple of mags, I've should have had a rifle to start with.

 

[Qwiks draw]

Not saying it cannot happen. Just odd. Thought to put things out there that might account for some of that.

 

[coy1369]

I know what ya mean. I really do appreciate the reply you and the other members posted. maybe i can get out sometime this week end and try it again. by the way, i ordered a set of fire sights from cheaper than dirt today. I have several pistols and i hate having just one that has to be aimed like the straights 8's.