adjusting for distance

Doc Holliday 1950 · February 11, 2015, 08:51 PM

Using a 38 P+ 125 gr. HP in a 2" revolver what the deviation difference at 5 yards vs. 20 yards? Then using a 4" revolver same scenario? Then 50 yards, then 100 yards? All responses welcome.

Bob Wright · February 11, 2015, 10:31 PM

Best answer I can give you is to try it yourself.

My guess it that it may be about a foot low at twenty yards.

Bob Wright

Deaf Smith · February 11, 2015, 10:41 PM

Doc,

20 yards is not that far.

If you snub is sighted in at 7 yard, dead on, with the target right on the top of the front sight, I think it will be a few inches high at 20 at the most. 5 yards it might be 1/4 inch low.

The 4 incher would be just a bit differnt but not more than 1/2 inch.

Depends on what range you sighted your gun in more than anything.

Deaf

Snyper · February 11, 2015, 11:58 PM

The easiest way to compare impact points at different distances is to look at trajectory charts

If you use a ballistics calculator, you can see how velocity affects the trajectories

It's largely dependent on the "zero" distance

g.willikers · February 12, 2015, 11:04 AM

What size target are you using?
Unless you're trying to put all the shots in the same hole,
My guess is not much difference until you get to around 50 yds.
I quite often practice at 50 yds with a .38 and a .45, and, with six inch circles, use about the same hold as for the 15 yd target.
Most shots hit near the center, (when they hit at all

)

g.willikers · February 12, 2015, 11:11 AM

P.S.
This conversation reminds me of what a retired ballistic physicist told me about how artillery is sighted in.
He said that all the computer and trajectory info is used about the way we use a bore sighter.
After that, it's shoot 'em and see where they land.

Bob Wright · February 12, 2015, 03:17 PM

At seven yards just about any gun is going to hit about dead center. More than likely a .38 is sighted in with 158 gr. bullets. A 125 gr. pill is likely to print low as the range gets reasonable.

Bob Wright

RickB · February 12, 2015, 07:15 PM

Buffalo Bore shows their 125gr +P load, if sighted for zero at 25 yards, will be 1.22" low at fifty, and 10.2" low at a hundred.
The barrel length doesn't make much difference, but the longer barrel will have slightly higher muzzle velocity, so it won't drop quite as much.

February 11, 2015, 08:51 PM	#1
Doc Holliday 1950 Senior Member Join Date: June 16, 2014 Location: Bout as south as it gets Posts: 1,238	adjusting for distance Using a 38 P+ 125 gr. HP in a 2" revolver what the deviation difference at 5 yards vs. 20 yards? Then using a 4" revolver same scenario? Then 50 yards, then 100 yards? All responses welcome. Last edited by Doc Holliday 1950; February 11, 2015 at 11:24 PM.

February 11, 2015, 10:31 PM	#2
Bob Wright Senior Member Join Date: July 10, 2012 Location: Memphis, Tennessee Posts: 2,989	Best answer I can give you is to try it yourself. My guess it that it may be about a foot low at twenty yards. Bob Wright __________________ Time spent at the reloading bench is an investment in contentment.

February 11, 2015, 10:41 PM	#3
Deaf Smith Senior Member Join Date: October 31, 2000 Location: Texican! Posts: 4,453	Doc, 20 yards is not that far. If you snub is sighted in at 7 yard, dead on, with the target right on the top of the front sight, I think it will be a few inches high at 20 at the most. 5 yards it might be 1/4 inch low. The 4 incher would be just a bit differnt but not more than 1/2 inch. Depends on what range you sighted your gun in more than anything. Deaf __________________ “To you who call yourselves ‘men of peace,’ I say, you are not safe without men of action by your side” Thucydides

February 11, 2015, 11:58 PM	#4
Snyper Senior Member Join Date: December 16, 2013 Location: Eastern NC Posts: 3,047	The easiest way to compare impact points at different distances is to look at trajectory charts If you use a ballistics calculator, you can see how velocity affects the trajectories It's largely dependent on the "zero" distance __________________ One shot, one kill

February 12, 2015, 11:04 AM	#5
g.willikers Senior Member Join Date: September 28, 2008 Posts: 10,442	What size target are you using? Unless you're trying to put all the shots in the same hole, My guess is not much difference until you get to around 50 yds. I quite often practice at 50 yds with a .38 and a .45, and, with six inch circles, use about the same hold as for the 15 yd target. Most shots hit near the center, (when they hit at all ) __________________ Walt Kelly, alias Pogo, sez: “Don't take life so serious, son, it ain't nohow permanent.”

February 12, 2015, 11:11 AM	#6
g.willikers Senior Member Join Date: September 28, 2008 Posts: 10,442	P.S. This conversation reminds me of what a retired ballistic physicist told me about how artillery is sighted in. He said that all the computer and trajectory info is used about the way we use a bore sighter. After that, it's shoot 'em and see where they land. __________________ Walt Kelly, alias Pogo, sez: “Don't take life so serious, son, it ain't nohow permanent.”

February 12, 2015, 03:17 PM	#7
Bob Wright Senior Member Join Date: July 10, 2012 Location: Memphis, Tennessee Posts: 2,989	At seven yards just about any gun is going to hit about dead center. More than likely a .38 is sighted in with 158 gr. bullets. A 125 gr. pill is likely to print low as the range gets reasonable. Bob Wright __________________ Time spent at the reloading bench is an investment in contentment.

February 12, 2015, 07:15 PM	#8
RickB Senior Member Join Date: March 1, 2000 Location: Boise, ID Posts: 8,518	Buffalo Bore shows their 125gr +P load, if sighted for zero at 25 yards, will be 1.22" low at fifty, and 10.2" low at a hundred. The barrel length doesn't make much difference, but the longer barrel will have slightly higher muzzle velocity, so it won't drop quite as much.