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Coated POI different


ES13Raven

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So I tried out some coated bullets for the first time yesterday - 147 FP out of my CZ SP-01 Shadow. I was chrono / group testing at 25 yards.

My sights are zeroed at 25 yards with plated and jacketed in both 124 and 147. The lines across the top of the slide, compared to the line of the sight cut make it easy to see if the sight has drifted (see pic below).

With the coated, the POI was consistently about 3" left, with several different power factors (127-135). Anyone else experience this with coated?

P8678jgl.png

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It isn't the coating. Different bullet profiles, different powder charges, the amount of crimp, the size of the coated bullets vs the size of the plated and FMJ bullets all these variables will influence POI. Find the bullet and powder that you like, that you CAN get a years supply of, work up a load and sight your gun in for it and forget about it.

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My Shadow does the exact same as yours. All coated bullets regardless of weight print 3" to the left. Only problem i have with that is my rear sight will not move so i cannot account for it. i have also noticed that 200 grain .40's will print 3 inches to the right in my Glocks as opposed to 165 or 180 grain bullets. So, different bullets, different POI is a rule.

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I noticed that yours is where mine needs to be to center coated bullets. Other than canting the gun over, which would make it shoot to the left, it does not take a whole lot of stackable tolerances to cause your problem. When I started shooting many years ago I was canting the gun slightly and could not get anything to center for me. It only takes a slight amount of cant to do this. You might do some measuring to make sure the barrel is centered in the front of the slide or is the hole in the slide has been bored slight off center. It only takes a tiny amount to cause problems.

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I noticed that yours is where mine needs to be to center coated bullets. Other than canting the gun over, which would make it shoot to the left, it does not take a whole lot of stackable tolerances to cause your problem. When I started shooting many years ago I was canting the gun slightly and could not get anything to center for me. It only takes a slight amount of cant to do this. You might do some measuring to make sure the barrel is centered in the front of the slide or is the hole in the slide has been bored slight off center. It only takes a tiny amount to cause problems.

Good idea. I just miked it several times.

SP-01 Shadow:

Left side = 0.2005

Right side = 0.192

SP-01:

Left side = 0.195

Right side = 0.196

My SP-01 the sight is centered and shoots POA.

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Well, ES13Raven, now I absolutely must test this out. Bowenbuilt is one of the people here I pay attention to, someone who does tons of testing with attention to detail, so now I'm going to have to test this out and look for it. Maybe I have in fact experienced this and falsely attributed it to myself.

If you've shown me a way to blame shooting problems on something other than myself, I'll owe you a beer. ;)

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