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2K views 22 replies 20 participants last post by  BFPGW 
#1 ·
Seriously, I have a large box of mis-matched 45-70 ammo, from a variety of different manufacturers. I want to use it to help rough in a scope sighting, before using the Good Stuff for the final sighting.

I'm assuming that the mis-matched ammo will work fine for the left/right scope adjustment, but that I will need to use the Good Stuff for the up/down adjustments and final dial in.

Is this a good assumption that will help me save a few bucks ?

Thanks

Regards,
Rich
 
#3 ·
How much do the bullet weights vary? Everywhere from 300 - 405 grains?

Barrels oscillate during firing, vibrating not only up and down, but side to side, and this oscillation/vibration can change pretty radically depending on the load. It's not that unusual to find different loads throwing bullets not only to higher or lower points of impact, but also to the side. So, both windage and elevation can be affected.

That's not to say that you couldn't get a rough zero, if you had say, a variety of 300 gr factory ammo all loaded to about the same velocity. It just might work out, but it's not something I'd want to count on.

Also - the 405's and the 300's shot to very different points of impact with my .45/70 Marlins. Far enough off to not even be useful.

Regards, Guy
 
#5 ·
I'm curious. Just how many shots do you think it will take to get from "on the paper" to zero? Do you understand scope adjustments? Take a measuring tape with you and count your inches from zero and adjust your clicks accordingly, at an established range, ie 25, 50,or 100 yards, maybe 125 with a 45-70. If you maintain the same POA, you should be able to walk it in in three shots with the "good stuff" 5 at the most. Then wizz away the mix and match just having fun.
 
#7 ·
Dang left me out of the conversation as soon as you required knowledgable:ahhhhh:
 
#11 ·
Also - the 405's and the 300's shot to very different points of impact with my .45/70 Marlins. Far enough off to not even be useful.
This has been my experience. I have tried and tried to get loads with the different weights to print close together, to no avail.

What I have noticed is that my rifle will take various loads of the same weight bullet and print them close together. The best is two 300 grain loads, one a Hornady and H4198 at 1600 fps, the other Speer Unicor and H322 near 1900 fps. They group about an inch apart at 100 yards, essentially interchangeable.
 
#12 ·
Looking at my notes, shooting various 300, 405 and 475 grain loads at the same target at 100 yards (Marlin 1895SS). Some loads were 16" higher, but none of the loads were more that 2" off side to side. As trapper-xx says, start at 25 yards.
 
#13 ·
I'd only use the mixed old stuff to get on paper at 25 or 50 yds. If you bore sight it you could forego using the old stuff completely. I always bore sight a new rifle/scope combo before heading to the range. It is amazing how close you can get it by doing a good bore sight job. I'll also use the bore sight to double check my rifles before going on a trip. If flying someplace with your rifle bring along the bore sight to check when you arrive in camp. Baggage handlers are pretty rough with gear sometimes.
 
#16 ·
THIS ASSUMES THE USE OF A SCOPE.

Just last week sighted in a new Vortex Diamondback scope. It was bore sighted by my gunsmith after mounting. I used the same handloaded ammo (25-06). Took 6 shots, all at 100 yds, shooting at a 16x16 hatched (at 1") target using bi-pod and rear bag. First 2 shots were off the paper. HOW?

First shot center aim, nothing on paper.
Starting 9 o'clock left edge of paper, fired 2nd shot.........nothing.
3rd shot, 12 o'clock high edge of paper.........found hole at 5 o'clock - 12" low and 5" right, from sight point. (sometimes you have to shoot all 4 edges)
Made adjustments, shots 4-6 tuned, "for good enough".

Once the gun is sighted in, then I work up loads to establish what shoots best in that particular rifle and really fine tune the groups.

A good bore sighting usually works with this method.

Have sometimes used the 25 yard method but with confidence in the bore sight, prefer this 100 yard method.

Not a "Technical Expert"....an ol' wise man showed me this a few years ago. :embarassed:
 
#17 ·
http://www.marlinowners.com/forum/g...82687-scope-mounting-bore-sighting-tools.html

Post #5. This is the same method that has been proven by many members to be the most economical on ammo. I don't use scopes often, but when I mount one it usually gets me within a couple inches of the bull before I put any ammo in it. Unless the user is bad at adjusting a scope, after bore sighting down the barrel it really shouldn't take more than 2 to 5 rounds.

As far as using mixed ammo, I have found that different brands of the same bullet weight and approximate velocity can print as much as a few inches right or left as well as up and down from each other. Not everytime but enough for me to never substitute ammo unless I have checked it for zero.

Lastly, when using a scope with typical crosshairs, use a target that is square. Align the crosshairs so one corner of the square is matched to one quarter of the scope reticle. It is sometimes easier to zero for folks than using a round target or similar.
 
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#18 ·
Myself, I'd sight in my scope with the ammo I most likely intend to use, compare several brands and weights actually, see what groups best and fine tune to that choice. Then later/afterwards just use the other ammo maybe out of interest depending on what bullet weights, brands, etc., you've got there. Basically to me, that mixed bag of rounds would be fun ammo to just "shoot up" mainly so to say. I dunno'... I just don't really see any savings really doing otherwise... unless just to make sure you can hit paper at 25 yards first time out of you know what I mean?
 
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#19 ·
Keep weights sorted to similar weights. Changes in weight and velocity will make a difference in horizontal as well. The high weight of .45/70 bullets cause significant torsional twist of the gun inducing lateral changes due to recoil and barrel harmonics.
 
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