First shot ALWAYS high, help

[Bravo_Victor]

Ok so i have a Czechmate, which always shot fantastic. Moved to a 2011 and havnt shot it in a year with major. Shot some light steel loads at a few steel matches, then converted it to Iimited and shot some 95pf loads at a few steel matches using 100gr plated Berrys bullets. Now my 2011 is out of action so i converted my CZ back to open and began to zero it at 20 yards. Heres the issue. Every single time, in a 3-4 round group after i load the mag and chamber a round, the first shot is like 4-6” high and slightly to the left. Everything after that is POI/POA to some extent bc even those rounds are 1-2” apart but atleast its still hitting where its supposed to. I can replicate this every single time. What could be the issue? Ive read all kinds of theories like barrel lockup, extractor, barrel fit etc but why would this be such a sudden thing? Any idea?

[regor]

30 minutes ago, Bravo_Victor said:

I can replicate this every single time. 

 

From a ransom rest or are you still holding the pistol? Could be a grip issue and after the first shot your grip "settles in", so to speak and leads to a consistent POI. Try putting the gun down and then pick it up between every round fired and see if it still displays the same behavior. 

[CHA-LEE]

Sounds like an inconsistent lockup. Try using a new or heavier recoil spring.

[Bravo_Victor]

9 minutes ago, regor said:

 

From a ransom rest or are you still holding the pistol? Could be a grip issue and after the first shot your grip "settles in", so to speak and leads to a consistent POI. Try putting the gun down and then pick it up between every round fired and see if it still displays the same behavior. 

Its from a rest and is rock solid

[Bravo_Victor]

5 minutes ago, CHA-LEE said:

Sounds like an inconsistent lockup. Try using a new or heavier recoil spring.

Ill try this

[Hi-Power Jack]

1 hour ago, Bravo_Victor said:

 shot some 95pf loads ;    converted to Open - the first shot is 4-6” high.    why would this be such a sudden thing? 

 

Sounds like you installed some very weak springs for the 95 PF loads, and as everyone said, you need to

install some stiffer springs for Major loads

[Bravo_Victor]

13 minutes ago, Hi-Power Jack said:

 

Sounds like you installed some very weak springs for the 95 PF loads, and as everyone said, you need to

install some stiffer springs for Major loads

Negative, the 95pf loads used an 8lb spring and the Major loads use the usual 10lb factory spring. I’ll toss a cajun 10lb in there and maybe an 11 to see. Just weird bc the same factory spring didnt have these issues. 

[lacivilian]

You see this sometimes when a person lightly racks the slide on the first round and if the gun is a looser fit it won’t lock up fully. Try to pull the slide back and then slam it forward. Then shoot a group and see if the POI changes. It shouldn’t after that. 

[Bravo_Victor]

Ok so i put in a new 10lb, tried an 11 and for shits and giggles i tried an 8lb and came up with the same result, this:

 

im somewhat convinced its just the load im using. I tried some of my production loads and it didnt seem to yield the same result. Still doesnt explain why the first shot is always so off and the rest are 3-4” groups at best. Im using RMR 124gr JHP which worked pretty well in my 2011 Open gun. My 2011 loads with this bullet were 9.9gr of AA7 @ 1.110 yielding 168pf and the CZ loads are 9.2gr of AA7 @ 1.080 yielding 168pf. I know it seems short but thats just how these bullets are. This is all off a rest at 20 yards, dot is perfectly still with no movement. The CZ is usually a tack driver. 

 

 

Edited October 26, 2019 by Bravo_Victor

[Bravo_Victor]

Im also going to take the optic and optic mount off to see if thats the issue

[Hi-Power Jack]

7 hours ago, Bravo_Victor said:

  going to take the optic  off to see if thats the issue

 

Good idea, but I doubt it.   If it was the optic, you wouldn't get a group anywhere.

[KrisS]

Maybe your ammo has too shallow seting depth or to weak crimp. Maybe while loading first round the bullet is pushed deeper than during all other shots. You get higher speed of the first shot and higher poi ? Just a theory. You could use different ammo or crimp yours stronger ?

[Hi-Power Jack]

3 hours ago, KrisS said:

Maybe your ammo has too  weak crimp. Maybe while loading first round the bullet is pushed deeper than  all other shots. You get higher speed of the first shot and higher poi ? 

 

Interesting theory, but in semi-autos taper crimp doesn't hold the bullet firmly in place -

unlike revolvers with the roll crimp.  Semi-autos rely on the sizing die to hold the bullet

firmly in place.

[KrisS]

Imho what keeps the bullet is mostly neck tension. Although in major ammo where oal is longer and bullet sits very shallow additionall crimps helps a little (but maybe not much). On cmj bullets I use when I apply more crimp there is a „step” that holds bullet in place and prevents (maybe marginally) the bullet setback. If he changes crimp and there is a change in the 1shot pattern then it is ammo related. Changing ammo to different kind /make would be even better of course. I could be wrong though. That’s just unconfirmed theory

Edited October 28, 2019 by KrisS

[racerba]

maybe it's not the first shot that's high, but subsequent shots are low...