18 February 2003, 01:49
HerrBergSeveral loads, one (horizontal) point of impact
OK, it's time to start my second year as a reloader. The first year I spent trying to make small groups for my rifles, not a very difficult goal to reach.
This year (and from now on?) I will focus upon developing loads that have the same POI, or at least they should be horizontally aligned. I have high requirements on terminal performance but the groups themselves only need to be "quite good".
I reload for .308WIn, .222Rem and 7x57R.
This is where I need some help. I will *try* to get loads that are usable without changing the scope:
1) A low-velocity FMJ roundnose
2) A high-velocity FMJBT for longer distances
3) A low-velocity, but heavy, SP
4) A high-velocity light/mediumweight SP for longer distances
5) A cheap low-recoil practice load (for .308Win)
6) A mean and evil varmint load.
I�ll have no problems with the POI�s not being perfectly aligned horizontally, but hopefully the speedier loads for long distances will have a highet POI at, let's say, 100 meters.
So, here�s my questions:
a) Any suggestions on methodology?
b) How do I fix horizontal problems?
Regards,
/HerrBerg
[ 02-17-2003, 16:58: Message edited by: HerrBerg ]18 February 2003, 02:50
DUKThere is one proven but time-consuming method called "trial and error"...
I played around a lot with my 30/06, 6,5x57R and the .222 Rem. It seems that for the bigger calibers the change of bullet weight gives very high differences in POI. A good compromise were finallz the Nosler bullets where the Ballistic Tips can be used for target practice and the Partition in the same weight for game. Usually the difference between the two in the same weight class is only one or two centimeters and still this can be reduced with a different powder load.
With the .222, I use 50 grain bullets with a reduce load for target shooting like runnig boar and 55 grain for hunting. If you load over a bigger range of powder volume, most probaby you can find the same or at least similar POIs. As I said, you have to try and play around, every barrel is different.
Good luck, DUK
18 February 2003, 11:36
NBHunterI do this with my 338WM. My heavy loads hit center at 100 yards, my A frames and X bullets hit at 2-2.5", and my 200gr rounds about 2.5" high. It can be a bitch to get them were you want, but I like you, like the idea of just loading the round and shooting. Usually I load up 1 each of a powder weight for a given bullet up to a max charge for that round. Example- 200gr load with one each of 70gr, 71gr, 72gr, 72.5gr, ex. Then I shoot them at the 100 yard target noteing whoes hole is whoes. If the round that lands were I want it to is OK in velocity, Bingo. Right now I have loads in 200gr (x 2), 217gr, 225gr, 250gr, and 275gr in one rifle and never touched the scope.
19 February 2003, 00:13
1894Trial and error but some things can make it easier.
Stiffer barrels generaly do this more easily and minimising the differences between powder and bullet shape/weight is a big help.
Remember coincidence may only be at the range you test at.