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Anyone else experience a POI shift in elevation with Blazer Brass 124g? Login/Join 
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The subject covers my question but there might be more to the story. Read further if interested in my puzzle.

I recently upgraded the OEM sights of my CZ P07 to a set of Night Fision sights. When zeroing those new sights at the range, the POI was higher than acceptable at anything beyond seven yards and as much as 8-12 inches high at 25 yards. For context, the OEM sights (#4 front) shot POA using a combat hold. The OEM #4 front is a bit taller than the #3, which I think is the manufacturer-installed front sight.

Given the most obvious/recent variable was the change in sights, my first thought was that the sights were simply not going to work for me, despite Night Fision specifying that their sights are OEM dimensions.

So, I reinstalled the prior set of sights and set out to zero the pistol. The results were only slightly better, with the POI much higher than before with the same OEM sights -- roughly 2" high at 10 yards, and higher the greater the distance.

I used ammo from at least two different boxes but they may have been from the same case. I suspect it could be another variable, but I tried to limit it being my shooting by shooting two-handed with each hand, offhand, and with a rest.

The pistol has about 6k rounds through it. My next step is to run some defense ammo through it (HST 124g) but wanted to get SIGforum's expertise in case there are other things to consider before/during my next trip to the range.

Thanks in advance.
 
Posts: 8 | Location: North Carolina | Registered: March 15, 2010Reply With QuoteReport This Post
Freethinker
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quote:
the #3, which I think is the manufacturer-installed front sight

I don’t pay much attention to exact POI with combat-style handguns, so I can’t answer your question about the ammunition directly. I am, however curious about something you mention.

With SIG factory sights, raising the sight number raises the point of impact. That’s true of both front and rear sights, but a higher number front sight for higher POI will actually be shorter than one with a lower number that’s taller. That’s because front sight height is inversely related to POI height. Are you sure that the manufacturer of your sights doesn’t follow the same protocol: I.e, is it possible that a #4 sight is intended to raise the POI over a #3, and something else is going on? Plus, you say “the #3, which I think is the manufacturer-installed front sight;” are you not certain about the standard front sight?

In addition, what do you mean by a “combat hold” (sight picture)? If it’s that you cover your intended point of impact with part of the front sight rather than using the old traditional method of placing the top of the front sight blade in the middle of the intended POI, do you know if the sight manufacturer follows the former method of regulating their sights?

To return to the ammunition question, though, what are you comparing the 124 grain BB to? It’s not uncommon for different ammunition to produce POI shifts. More powerful ammunition and heavier bullets that produce more recoil will often cause higher points of impact.

Or perhaps I misunderstood everything you posted, and you can just ignore all this. Smile




6.4/93.6

“Most men … can seldom accept the simplest and most obvious truth if it … would oblige them to admit the falsity of conclusions … which they have woven, thread by thread, into the fabrics of their lives.”
— Leo Tolstoy
 
Posts: 47276 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
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Thanks for the information about the SIG sight system. I've not needed to make adjustments to my lone SIG. Maybe there is a lesson for me there :-)

CZ, at least for the P07/09 models, appears to use a numbering system that as the front sight number increases, so does the sight height.

Regarding the default setup, I am not the original owner and do not know what the OEM installed sight was. I picked up on another message board that the #3 could be the default sight on these models.

I do not yet have a comparison for the Blazer Brass 124s because that's my standard the last five years or so. That's where the results from the next range trip will come in. I'll post my findings.

Thank you sigfreund.
 
Posts: 8 | Location: North Carolina | Registered: March 15, 2010Reply With QuoteReport This Post
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