Regarding the ever confusing Sig sight numbers, and caliber swaps, I've done some reading. My understanding is that the 6/8 sight would have a lower POI than a 8/8 sight, for the same caliber. Since the P239 is in 40 S&W, and fires a heavier projectile, the 6 front sight is appropriate given that the pistol is rotating upwards before the projectile leaves the barrel.

So, for a 357 Sig projectile, leaving a few hundred fps faster, and with 40 grains less weight, I believe the POI for a 6/8 would be low.

Any responsible opposing viewpoints?

(Jane, you ignorant... comes to mind)

This message has been edited. Last edited by: 4MUL8R, September 29, 2017 05:59 PM

Correct POI would be low for 357 with 6/8. Here's my targets for my P229/357 with 8/8 sights.

As numbers go down, groups go down.

P1010487 by greyeyezz

.40

P1010481 by greyeyezz

Given that the cartridge is supposed to be superior in many ways, I guess I need to consider the expense of a sight swap along with the already expensive barrel.

Unless you shoot at 25 yards or beyond, the difference in POI is hardly worth worrying about.

quote:

Originally posted by 4MUL8R:
Given that the cartridge is supposed to be superior in many ways, I guess I need to consider the expense of a sight swap along with the already expensive barrel.

Yup. That's one reason I haven't pulled the trigger on anything. Affordable DA/SA .357 Sig P229s in nice condition are scarce. Nice, affordable P229s in .40 S&W are plentiful, but, by the time you add a barrel ($140) and replacement sights... *shrug*

I shoot both .40 S&W and 357 SIG using the same slide and sights with my SIG P229. The sights I am currently using are the #8 front and #8 rear SIG X Ray sights.

Yes, if you use the same sight picture the .40 S&W rounds will hit a little higher than the 357 SIG as was shown. I simply use a different sight picture for the two rounds.

Most SIGs are set up for a "combat", "drive the dots", or #3 sight picture and I use that for 357 SIG. With .40 S&W I use more of a "split the bull" or #2 sight picture, and that seems to work fine for ranges of 15-25 yards or so.

Inside of that range, the difference in POI is really not worth worrying about. If you like to shoot at long ranges, since 357 SIG is a faster round it will shoot flatter, so the farther out you go the difference in POI narrows.

quote:

...given that the pistol is rotating upwards before the projectile leaves the barrel.

It may also be that you're over-thinking this a bit...