fixed sights on short barrel snubbies

[blackpowder]

Hi everyone,

Does anyone know how the sights are set at the factory on short barrel snubies such as the S&W Mod. 36, M-10 or M-15 or the Colt DS for that matter. They all seem the same regarding the fixed sights.

I find that the POI along the lateral axis is always centered, meaning there is no left or right divergence. However, depending on ammo, the vertical POI is always off, printing either high or low. Sometimes as much as 4 to 5 inches at 30 feet. Heavy bullets tend to go high and very light ones low. So what rule of thumb applies here? Or do I have to test each and every cartridge separately to see where the bullet actually hits in respect to the point of aim?

your advice is much appreciated...

 

[deadin]

Sights on a Snubbie are about like a 'scope on a shotgun. Seems like they should be a good idea, but they never work well.
As long as the windage is close, just aim (point) at the center of mass and you will either hit the target in the head or in the nether regions. Both of which should give the desired results.......

 

[Pisgah]

Generally speaking, .38 Special revolvers with fixed sights are regulated to hit dead-on at 25 yards using standard-velocity 158 gr. loads. Point of impact elevation will vary with range, weight of bullet, velocity of load.

 

[Babysitr]

playing with all that, getting it dialed in is half the fun! I thought all snubbies were close range deals,until I got a 2" model 15!

 

[blackpowder]

Example: Two .38special loads shot out of the same snubbie with a 2" barrel (actually 1 7/8 inches) from a benchrest hit on exactly the the same vertical axis at 25 yards. So the windage is rather perfect. But the first, a winchester 95gr. silvertip +P impacted an amazing 6 inches below a winchester standard pressure 158gr. LRN. And - here is the interesting part- the actual point of aim was pretty much exactly between the two. That's a rather big elevation issue which has nothing whatsoever to do with the gun as the result remained almost exactly the same using a Charter Arms Undercover with the same barrel length.

 

[Borderboss]

While sights are great on a small gun and you should know where they're aligned, generally I've always thought of small guns the same as cameras: point and shoot. So whether it's my snub pre-10 M&P, or my Kahr PM9, I know where the sights are aligned, but I practice to make sure I can point shoot the gun accurately under 7 yards.

 

[Jack Flash]

The heavier bullet has a lower velocity so it stays in the barrel longer, therefore it's more affected by muzzle rise caused by recoil. IE, the barrel is now pointed higher than when the trigger was pulled. So heavier bullets impact higher on the target. The lighter, faster moving bullet is also affected by muzzle rise, just not as much.

 

[murphydog]

The heavier bullet has a lower velocity and stays in the barrel longer, therefore it's more affected by muzzle rise. So heavier bullets impact higher on the target.

Correct, except it is more the effect of slower velocity - a heavy bullet with higher velocity will print lower than the same slower bullet.

And yes to the OP, every load has to be grouped, as you saw with the two .38 Special loads you tried.

 

[blackpowder]

ok, got it. Seems that recoil induced barrel rise is the cause of the higher POI of slower velocity loads....sounds logical but then snubbies should be least affected by this phenomena, right? The shorter the barrel, the faster the bullet exits and therefore the same heavy and slow load shot through a 6" barrel should print even higher. But I am not a ballistics expert.....

 

[crsides]

Except that longer bbl guns have more forward weight, offsetting the time in the bbl effect. The answer is if your gun is shooting high with heavy bullets, move to a light bullet to "dial it in".