Shooting high: is it me or the equipment?

[awp101]

Swapped the factory sights on a 4" .357 GP for a set of Williams Fire Sights and tried to get it zeroed for a 6 o'clock hold at 25 yards last week. I used the 8.5"x11" (I think) targets our range provides which has a 4" square with a 1" square bullseye. With the rear sight all the way down, using Magtech 158g FMJ .38 Special and rested on a MTM Front Rifle Rest, aiming at the bottom of the 4" square still put me about 2" over the bullseye.


So where should I be looking first for an issue? The sights are GP specific so I don't think the front sight is the problem. Could it be I'm using .38 Special and the sights are "regulated" for .357 even though they're adjustable?

I know I'm not a sharpshooter and I'm more used to dots and glass due to lousy eyesight but I do know to use "equal height, equal light" for irons.

In the end it's not a huge deal breaker because even that high at 25 yards will let me run the 15-20 yard plate racks at the range but my OCD is flaring up and needs an answer...

Thanks!

[bigbrowndog]

I’d say it’s your ammo, being slower and the heavy 158gr bullet. If memory is correct, longer dwell time in the barrel means it Will hit higher due to recoil forces already acting on the gun.

This info is from mr. Bradshaw,


Barrel Time and Point of Impact (POI)
a) Long barrel time raises POI.
b) Short barrel time lowers POI.

Bullet weight & Point of Impact
a) Heavy bullet raises POI.
b) Light bullet lowers POI.

Same bullet----Powder Burn Rate (BR) affects POI.
a) Fast powder (fast BR) shortens barrel time to lower POI.
b) Slow powder (slow BR) lengthens barrel time to raise POI.
c) Medium powder (medium BR) puts POI between fast and slow powders.

Trapr

[awp101]

Thanks for the chart! I knew there was a correlation between bullet weight and POA/POI but I couldn't remember which way it went. I also remembered the same grain .38 and .357 would have a different POI but again, I couldn't remember which was which.

[bula]

If butt of gun was rested, it will throw impacts high. I'll add, LOL, just back up until your on ! 

[awp101]

Jun 22, 2019 11:24:39 GMT -5 bula said:

If butt of gun was rested, it will throw impacts high. I'll add, LOL, just back up until your on ! 

My butt was rested but not the GP butt.

I'll just do like with the old SAAs, aim at the belly button to hit 'em in the head.

[45MAN]

TOO MANY TIMES THE FACTORY SIGHTS WILL NOT WORK WITH AMMO THE GUN IS EXPECTED TO BE USED WITH. MY 6.5 INCH S&W CLASSIC 45 COLT AND 5 INCH MODEL OF 1989 45 COLT REVOLVERS SHOT REAL HIGH WITH FACTORY SIGHTS WITH THE REAR SIGHT BOTTOMED OUT. MY 4.2 INCH SP101 327 MAG SHOT REAL LOW WITH THE REAR SIGHT UP ALL THE WAY. A GOOD SAMARITAN ON THIS WEBSITE MADE ME UP A LOWER FRONT SIGHT (NONE AVAILABLE FROM RUGER) AND A HIGH FRONT SIGHT FROM DAWSON FIXED THE CLASSIC (S&W DID NOT HAVE ANY FACTORY OPTIONS FOR THE CLASSIC), I AM STILL SUFFERING WITH THE 5 INCHER BUT AM WORKING ON FASTER LOADS FOR MY S&W 45 COLTS. MAKES YOU WONDER HOW MUCH, IF ANY, ENGINEERING THEY PUT INTO THE SIGHTS???

[groo]

Groo here
Also different sights "look" different.
Have someone else try it...