Some quick ballistics help please

[eddiegunks]

Hey all

I am down to the wire. I have a match tomorrow. I do not have much extra ammo for testiing. Bad planning on my part. Maybe u can help me.

I have a 5 inch open gun. Dot sight. It shoots great at 10 yards. Today i was checking it at 25. Just to be sure. Well it shoots like 4-5 inches high.

I was expecting a bit flatter.

I am using 3n38. 125gr JHP zero bullets at about 1340fps. Can u help me figure out where i should zero this sight? If i could save some time and ammo doing this it would be great. I thought it should be pretty flat.

Thanks for the last minute help.

Eddie

[GOF]

Your dot sight sits higher above the bore than iron sights, so if you zero at a close range the bullet is still rising to meet the dot at longer ranges. I would zero your gun at 25-30 yards, and you should be good to go for any USPSA match.

[gng4life]

I normally sight-in at 18 yards or so to split the difference. Good luck...

[Hi-Power Jack]

Eddie, you want to zero it between 15 & 25 yards - BUT,

it will then shoot low by 2-3" at 0 - 8 yards.

Not a matter of being "flat", but your sight being 2 - 3"

higher than the bore. Picture yourself placing the muzzle

against a target and you'll hit 2-3" below your dot, because

your muzzle is 2-3 " below your dot.

For tomorrow, at any distance to 20 yards, I'd just aim

at the center of the A zone, and aim at the bottom of the

A zone for any further shots (20 - 50 yards).

You should be fine tomorrow - but next time you sight it

in, sight it in for 15 - 25 yards.

Edited August 26, 2012 by Hi-Power Jack

[eddiegunks]

just wanted to say a big thanks for the help. i was not able to get it all together for the match in time, and as a result did not get to shoot open this time.

i successfully got the gun sighted in this morning and all is great.

cheers

eddie