Shooting 6" low?
I went out shooting yesterday with my USP full size 40 and at 15yds all the rounds grouped about 6" from where I was aiming. I had great groups but with the same ammo it used to hit dead on. I did a ton of dry fire exercises and the gun stayed steady. I only had the one type of ammo with me. Federal 180gr. Should I just chalk this up to an off day or something I should look at? Also my cousin shot the pistol and it did the same thing. The tempature was around 50 and I usually shoot when it's in the 80's. What do you guys think? Thanks
Off day. Had something similar with the USP 45. Went out a week later with the same ammo and was dead on.
You need to be farther away so the bullets have time to rise.
Did you forget to use a cover up hold and instead used a center mass or 6:00 hold? I've done that before switching out my sights to adjustable. I have never liked a cover up hold and have always used a center mass hold, so I would often forget and send a round inches lower from where I was aiming. As I said, that is why all my shooter HKs now wear adjustable sights. If that was not the cause I would not worry unless it shows up again. You could have had one of those oh-crap days where nothing you do is correct. Sort of like talking to many women (thank God my wife is not one of them). CYA statement.
Originally Posted By Big-Bore:
Did you forget to use a cover up hold and instead used a center mass or 6:00 hold? I've done that before switching out my sights to adjustable. I have never liked a cover up hold and have always used a center mass hold, so I would often forget and send a round inches lower from where I was aiming. As I said, that is why all my shooter HKs now wear adjustable sights. If that was not the cause I would not worry unless it shows up again. You could have had one of those oh-crap days where nothing you do is correct. Sort of like talking to many women (thank God my wife is not one of them). CYA statement.
I did use a cover up hold. What kind of sights are you using? I hate using a cover up hold and want something differant.
Originally Posted By AR45fan:
You need to be farther away so the bullets have time to rise.
Iv shot at 5,10,15,20, and 25yds before and all have hit where I was aiming.
I wish I could recommend the sights I use but the company has been sold and the new owners have an F rating from the BBB the last time I checked. The company was MMC (Micro Machine Corp or Company) and they made an outstanding adjustable rear sight. It was as snag proof and bullet proof as any fixed sight yet fully adjustable for elevation via a captive cam screw (cannot loosen it and lose the screw or have the blade fall out) and drift adjustable for windage via two set screws. They also have different configurations and colors of night sights and I like the bar-dot-bar which looked sort of like this: -o- with the o being the front sight. It was a great sight and I have 4 or 5 pairs of them, but then they went and spoiled it all by selling out to a company that does not seem to give a rat's ass about customer service or producing a quality product. I use to recommend them but started hearing all kinds of horror stories and then was told about the BBB rating and checked it out. Sad to say it was true so I cannot in good conscience recommend them any more. I did a quick search and it appears that they are no longer in business, which I suppose is a good thing since they appeared to be run by thieves after they were sold.
Anyway, I do not know of another snag-proof bullet-proof adjustable sight out there. I'd check with LPA, Mepro, Novak, Heinie, all the majors and see what they come up with.
The only other alternative is to take your pistol and the load that you shoot most often, and shoot it at a carefully measured distance, from a bench using a rock solid hold. Use the sight picture you want and shoot several 5 shot groups. Now, measure to the center of each group from where you want the bullets to hit and take an average of how far off they are from where you want them to be, then buy a taller or shorter front sight to bring it into zero. There is a formula for determining how much difference you need to zero and it is always correct, IF you take careful measurements. Remember, junk in equals junk out. 8.9 is not the same as 9 and 25 paces is not the same as 25 yards.
The formula is: Sight movement equals (sight radius times impact movement) divided by (distance times constant), or SM = (SR * IM) / (D * K)
IM is impact movement, or amount you want to move your groups center.
SM is sight movement in inches.
SR is sight radius, the back of the rear sight to the back of the front sight.
D is for distance, the range you are shooting at.
K is constant, 12 for feet, 36 for yards, 39.37 for meters.
Sorry I cannot be more help about your specific question.
So, if you need to move your impact three inches UP and you shot at a measured 20 yards, and your sight radius is a measured 4.75 inches, then you set it up like this: SM = (4.75 * 3.0) / (20 * 36), or 14.25 / 720. You need a .020 inch SHORTER front sight to move your impact movement up three inches at 20 yards (the actual amount was .01979 but honestly, .020 is as close as you are going to get)
