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223 zeroing
Posted: Tue Feb 05, 2019 8:22 am
by shotgun sam
A quick question I am sure someone will advise me on.
My usual zeroing area on the farm has been shortened to 75 yards as the farmer has temporary storing some lorries.
I would like to have the rifle zeroed for 100 yards how high above the center point will replicate that
Re: 223 zeroing
Posted: Tue Feb 05, 2019 9:11 am
by 1066
Not enough to to worry about..with just a guess at your bullet weight and speed of 55gn and 3,200 fps it looks like you'll be .16" low at 75 yds
Re: 223 zeroing
Posted: Tue Feb 05, 2019 9:56 am
by Sim G
Yep, just as he says....
For S&G just ran 55gn Sierra Blitzking at 3250fps for a BC of .271 through the calculator and 75 to 100 yards is a 0.1” variation.
Re: 223 zeroing
Posted: Tue Feb 05, 2019 10:28 am
by shotgun sam
Thanks 1066 and Sim G
Re: 223 zeroing
Posted: Tue Feb 05, 2019 12:20 pm
by breacher
Difference is so tiny you wont notice.
Re: 223 zeroing
Posted: Wed Feb 06, 2019 9:39 am
by Mattnall
breacher wrote:Difference is so tiny you wont notice.
Yep, and if you do want to off-set you'll most likely need to be below the aiming mark not above it.
Re: 223 zeroing
Posted: Thu Apr 04, 2019 2:12 pm
by Phoebus
I happened to zero my .223 yesterday at 100 yards and using my ballistic info, I'd be 0.2" or 5mm out at 75 yards but I'm running an 18" 1-9 twist barrel shooting 55gr's at 3240fps. Either way, it's negligible really.
Re: 223 zeroing
Posted: Fri Apr 05, 2019 7:58 am
by IainWR
If you have a fairly high line of sight above the line of bore that may be much more significant. You will need impact 1/4 of the distance between scope and barrel below the target to get a 100y zero at 75 yds, less the tiny little bit for gravity drop from 75 to 100.