Hello Geg
First lets start with the 10-12" at 1000 yards. I presume you meant group size?
The 180 gr bullet might shoot well for you at 500 yards but, I like the larger weight bullets such as the 220 Gr Sierra MK or even the 240 MK at 1000 yards especially in the size of case you are using.
Your scope has a TOTAL of 50 MOA verticle adjustment. If the scope is starting out at the BOTTOM of that overall adjustment you would have 50 MOA from a 100 yard zero. If your scope is on a straight "level" base and ring set up, that means you have 25 MOA to work with TOTAL from a 100 yard zero.
This means you would need a tapored base. Each .001" of tapor (Higher in the back end of the base) equals 1 MOA at 100 yards. So if you have a tapored base of say .020" you now have 40MOA usable verticle adjustment to your scope.
In reality though, you should have enough adjustment at 25 MOA to go to 1000 yards from a 100 yard zero, as it is set up.
I'm just adding info here in case you want to go further then 1000 yards in the future.
Most rifles on the average should have 22 to 25 MOA verticle adjustment to shoot at 1000 yards. I keep adding from a 100 yard zero.
We find at Williamsport, most all 30 Cal mags need 22 to 25 MOA (88 to 100---1/4 Min clicks from a 100 yard zero) to get on target. That's an average.
Learn to start your zero at 100 yards and always work from and back to there. Much easier to NOT get confused as to where you were to start with.
You will need to run your bullets over a GOOD reliable chronagraph to get the extreme spread of your loads and cases (seperate them to the lowest extreme spead for your match cases) used and also to get the velocity you are after. The velocity is needed when programing the info into a ballistics program.
You might want to try Reloader 25 in your rifle with the 220 or 240 gr bullets if you switch to them.
Well lets see now, we have the bullets and powder, the MOA, the chronagraph and now it's up to the loader and shooter to see if you can get the 10" to 12" group?
Remember start at a 100 yd zero first, put 22 MOA --88 clicks on your Leupold and shoot at 1000 yards. If it takes more or less clicks, adjust until your on target. A good set of bigeyes, binoculars or spotting scope can be helpfull also.
If you don't have a computer ballsitics program, I would get one. If you have a program and put in your speed and all other infomation, you shoud be real close to what the printout tells you as per MOA needed at the various yardages.
I hope that's the info needed for what you were asking.
Good luck
Darryl Cassel
PS-- The accuracy level for paper target shooting and with the 220 gr bullet is normally 3000 to 3040 FPS or a bit higher (3100) for your sized case.
[ 02-23-2002: Message edited by: Darryl Cassel ]
