I disagree. I played around a couple of weeks ago with different bullet weights in my 4" S&W M13-2, which hits to POA with 158 grain ammo in both .38 and .357. Both 125 grain Winchester PDX HPs in .38 and Speer .357 135 grain SBGDs hit about 5" low at ten yards. That's enough to matter.
OTOH, standard weight HSTs (9x19 - 124, 40 - 180, 45 - 230) hit right to POA in my autoloaders once they were adjusted for windage.
I will check my guns poi at 25 yards with carry ammo and change out sights from those groups. I will also see what my training ammo is doing but unless it's way off I won't change anything.
The Rhode Island CCW qualifier is 30 RDS at 25 yards on an Army L (b-22) target so friends and I shoot it as a competition for ourselves. My best group sizes are around 12" which is hardly world class but it does give me a good enough group to center.
This was shot with my beretta m9a1 compact frame/vertec slide with Wilson sights. Their front night sight and their .300 rear battle sight. Shot with Winchester NATO.
Attachment 23706
This was done with my Springfield Loaded with a fusion rear ledge sight that is higher than stock but I don't remember the number. Shot with gold dots. Both targets inside 4 minutes and I think the top target was inside 2 minutes. I used a 30rd magazine
Attachment 23707
This is why I buy ammo by the case, and generally cases of the same lot if I can get it. I generally buy ammo once or twice a year and get 5-7K at a time.
Regulated for who and for what ammo?
I'll try to keep this short ..... different people have different sized hands and hand geometry. So they interface with the gun slightly differently. Different ammo (especially different bullet weights) hit at different POA/POI . I had a student come to class several years ago who had SOLID mechanics and was consistently shooting a 1 hole group at 5 yards.... but it was about an inch and a half to the left. Not LOW and left...just left. I went over and looked at what he was doing watched him shoot a few rounds and he asked if I knew why he was consistently left. I asked if I could shoot a few and when I did they went in the same hole he was shooting. I told him at lunch we'd move his rear sight over a little and see if that fixes it. It did. He asked how I knew so quickly what the problem was. He said he had been to 7 different instructors (some VERY well known) and none of them had been able to diagnose the problem. I told him I knew what it was because I actually have the same issue. On single stack guns I need the sights pretty well centered up but with glocks I have to drift the rear sight a small amount to the right to get it the POI "centered" for me.
For ME , when I have the gun aligned with the web of my hand and bones in my arm glocks shoot a tiny bit to the left for me with typical 115 grain ball. Not low and left, just left. It is NOT an issue of me pushing the trigger left, not an issue of my index finger "bicep" pushing the gun left, nothing like that. It is apparently the way the frame in recoil reacts with my grip. Most people shooting a pie plate sized group at 5 yards would never even notice it....but since I windage zero them to be able to hit 1" pasters at 7 yards I do notice it.
So what about ammo? When I windage zero a pistol for 115 gr ball it will shoot anything faster than that a tiny bit to the right and anything slower and heavier to the left and HIGH. So if I then use 147 ball in that pistol I have a POI shift from POA of about 3-4 inches high and left at 15 yards. So if I plan to be able to make down 0 hits (IDPA) at 35 yards ( IDPA standards stages can have targets out to 35) then I really need to stick with 115 (or rezero it for 147 ) because 147 impact would be up in the right shoulder area or completely off the target.
When I zero carry guns for my typical carry ammo (CCI Gold Dot 124+p) then anything slower than that will go left and anything heavier will go high (and left since it will also be slower) . So I pretty much need to stick with that particular ammo if I expect to make shots on eyesocket sized targets at 10 yards...or snipe flies at 5 to 7 yards (some of you that will read this know what I'm talking about). If I take 147 ball and try to shoot it in my carry gun on anything small or at any distance I have to aim low and right to hit center.
And the type of sights does not seem to matter with regards to windage. Whether it is factory plastics, trijicons or whatever I have to move the rear sight if I expect to shoot POI to POA. For the last decade I've typically used Warren/Sevigny sights. Most are aware that they have 2 different front sight heights. Their website says one is for long slide guns (.245) and one is for regular length (.215) but in my experience it has more to do with bullet weight than slide length. My Gen 3 G34 needs a .215 for 115 gr or 124+p to be centered at 25 yards....the .245 puts them low on the target. My Gen4 G34 hits POA/POI for elevation at 25 with 147gr with a .245 front but needs a .215 for POA/POI with 115. My Gen 3 G17 with the .245 sight throws shots low but the .215 is centered at 25 yards. The last carry gun (Gen 4 G17) I zeroed with 124+P at 25 yards shot about 4 inches HIGH with the .215 height front. I had to put a .245 height front on it and it was dead center. BUT my other GEN 4 17 needed the .215 to center up elevation at 25 yards.....so was that last one just an anomaly? Probably. Point is you have to shoot the gun with the ammo you will be using.
So with regards to the initial conversation what does all this mean ? It means that the factory simply cannot predict bullet weight or how the end customer will grip the pistol . Even if they ransom rest it at the factory and tell you what ammo they shot it with does not mean that it will necessarily shoot that way for the end user....even if the end user is an excellent shooter. Each shooter will have to zero it for themselves and for their chosen ammo. It MIGHT even require a different height sight. Does it matter to "the majority of shooters"? Probably not since the majority of shooters can't shoot a 5" group at 5 yards. but if you want the gun to throw bullets where the sights are pointed we may need to refine the zero from what it was factory set at. Most times the factory just centers the sights and fires it for function.....
Last edited by Randy Harris; 02-14-2018 at 10:19 AM.
Yesterday I shot some 30 yd groups with a Shadow2, and was surprised to see my pattern shifted 6” right. After checking if my rear sight was loose (it wasn’t) I realized the sun was behind and to the right. That was blurring the right side of the notch and causing my right POI shift.
A harder rear sight focus fixed it.
Last edited by Clusterfrack; 02-14-2018 at 12:46 PM.
“There is no growth in the comfort zone.”--Jocko Willink
"You can never have too many knives." --Joe Ambercrombie
Decided to shoot a SW 19 in IDPA today. First stages, shot low till I figured it out. I hadn't shot the gun in a few years. On the last state, I put two rounds in the same hole on the farthest target. Obviously, that's my real ability level (haha!). The low shots - it's me not being used to the heavier trigger pull at first.
To humble us - some young man about 12, kept on running stages at zero down with a Glock 9mm. Sigh - youth.