Very interesting, as you stated, that is what I have come to understrand the 8/8 is good for 9mm and 357sig. Guess I'll find out with my P226 357sig, originally a 40 ....

 

I am playing the sight game with a 229 .40 slide.

I got it with 8/8 sights that were dead.
The sights that were on my M11-A1 were new and the front was a 6.
Swapped them over to the .40 slide and was low, as in not on paper low. .357 wasn't any better.

Finally broke out the dial indicator and found that the M11-A1 rear sight was a 6 (.230") and not an 8 (.250"). I thought the 6 was a light punched 8 and just assumed that it was an 8 as that's what my 3 others had.

I measured the rear sight I took off my 229 Select and it was an 8 so I put that on and the old #8 front (.220")
Headed out tomorrow to see what it's doing now and will take a 6 front as well.
I'll use the .40 barrel as that's what was in it in with the 8/8 sights and get a baseline.
Something I should have done to begin with.

 

Before blaming everything on the sights, examine your fired cases. If the primer strike isn't centered in the primer, the barrel may not be "aligned" for the offset of the sights. Specially on an newly installed barrel.

Are you firing from a "rested" position, single action at 25 yards?

 

i will have to find some of the 357 brass to look at a primer strike, for the 40 will just have to have my son spot where it lands, I shoot 4 different 40s out there, if its not hitting center of the primer how do I adjust the barrel fit to the slide ? or do i need a good Smith to fit the barrels?

 

My comment was intended, to show some of the variables involved when POA/POI isn't always spot on. Even something like the centerline of the bore, being slightly off center will do it too.

Much of it is how far into the ejection port the barrel goes to lock. Unless you know the orientation of the cartridge case in the chamber, it's hard to tell.

Barrel Alignment Gauges ( https://www.brownells.com/gunsmith-...ools/barrel-tools/barrel-fitting-tools/1911-barrel-alignment-gauge-prod906.aspx) were used to fit 1911 barrels, and could be used in this case too. It wouldn't necessarily need a gunsmith, but a gunsmith would understand, and possibly have the gauges if he was a "Pistolsmith" that fit a lot of barrels.

Dykem is used to coat the breech face, and the gauge is slid down the bore, it has a firing pin sized protrusion which optimally would slide into the firing pin channel. If it doesn't, it will leave a mark in the Dykem showing where it contacts. Remember, just like the rear sights, .010" difference at the pistol means about 2" difference at 25 yards.

 

It could be the barrel. I bought a Barsto .357sig conversion barrel for my P229. It was fitted by a very good Smith and it shoots 4” low at 10yds. Had to install an adjustable rear sight to solve this issue.

 

Post like this are exactly why I joined SigTalk. Willard, as usual, thanks.

 

i found a pile of ..357 and 40 about 10 feet from where I was shooting everything on both set of cases was pretty centered a few of each showed a very small drag mark on the primer but it wasn't on all of them so I'm guessing this may have been me shooting some fast double or triples or it could just be a thing , who knows?

main thing is it is hitting where I'm looking again so I'm going to run with it

 

Just got back from trying mine the way it showed up.
229 Legacy slide with a .40 barrel and 8/8 sights.

It was set up for .40 with 8/8 sights as the POI at 15 and 25 yds was behind the dot.
.357 was low.
All zeroing done while seated and supported.

Putting the sights that were on the M11-A1 that I thought was 6/8 really screwed it up.
Especially when it was actually a 6/6. 2" low in the front and 4" low in the rear.

I will need a #9 front to be able to use a .357 barrel it seems.
Both .40 and .357 primer strikes were dead center.
A Dawson precision .215" fiber optic front should work for .357 and is the next one to try.

 

Did we start seeing some pistols (9mm, I believe) showing up recently that did not have the standard sight numbers we are used to having. I can't remember if some were seeing differences on other calibers. But if those newer slides with non-standard sight numbers maintain the same sight picture, SIG would have to adjust the depth of the dovetail cut to compensate. If that is the case, and if any of you have such a recent pistol and you start swapping sights onto older slides, you might not get the results you expect due to the different depth of cut on the dovetails.

 

Ya know what?
Take the 8/8 for .357 and 9mm and 6/8 for .40 and .45 and just toss that out the window.

I also took out my 86 P220 that I had installed Trijicon HD XR sights on. Ordered as a .40 and .45 with 6/8 sights.
I thought it was low when I first tried it and today was set up for supported shooting and tried it again. Very low, close to 4" to low.

The original sights have no numbers and once again I assumed it was 6/8. WRONG
When measured they are 8/8 for a 1986 P220

No excuses as I have several dial calipers and should have measured twice and bought once. LOL Good grief.

The only gun I have with sights that it's "supposed" to have is the 226 with 8/8

M11-A1 6/6
228 6/8
229 Select 6/8
229 Legacy .40 8/8
WG 220 8/8
226 Legion-9 8/8

The XS sights on the 228 are on and the Speed Sights on the 229 Select are on target at least. Whew..

 

I need to bench all my pistols but I'm afraid they will all be off now lol i will just keep adjusting on the fly like I always have, I know where they all hit

 

Every individual gun is different. 8/8 and 6/8 are general, but not definitive.

 

Where bullets hit will depend on muzzle velocity too. All else being equal on your P-series, and not adjusting or replacing sights, the faster the bullet, the less time it spends in the barrel. And importantly, the less the bullet is affected by JMB's short recoil breech unlock action which has the barrel chamber end tilting downward to unlock as the bullet is traveling down the barrel. Slower bullets obviously spend more time in the barrel and are thus angled more upward in relation to slide and sights.