Scope adjustment based on loads

[newton]

I am fixing to load for my boys 308 and had a quandary.

I am going to load mostly 100 yard Ed Harris type loads for most of his shooting using some 4227 I picked up. But then, I want to also load some stuff a little warmer, most likely using different powder, for when I take him hunting.

All of this is going to be based on what the rifle likes of course, but my curiosity is the scope adjustment.

I am curious if I anyone has found a good "zero" for one load that works at a given dope for the other. I am not sure if this makes sense or not.

The turrets are easy to adjust, so as long as there was not any horizontal movement then I am wondering if a zero for the target load at 100 would be best or a zero for the hunting load would be best, and moving the turret for the other load.

Maybe I can put into words better what I am thinking tonight, but thought I would throw this out there in case someone understands what I am asking.

[rsrocket1]

I did that with my Remington 788 .308. This gun is very accurate and holds groups well at many different velocities. The problem is that the groups don't grow or shrink as much as move around the POA/POI. So what I did was zero the scope with a standard 150g bullet at 2640 fps (good stout "hunting" type load with a JSP). I then develop loads with other bullets from 113g at 1700 fps to 170g @ 2000 fps to 200g @ 1020 fps. I adjust the load so that the POI is approximately the same as the 150g bullet @ 2640 fps. The load might be adjustable to get a tighter group, but if it moves the POI, I will stick to the load with the same POI rather than move the POI for a tighter group.

This way, I can have a mild shooting 25-50 yard plinker load for the kids where I don't need to readjust the scope when switching developed loads. 2 liter soda bottle or clay pigeon accuracy @ 50 or soda can at 25 is good enough.

[duckey]

Sounds like you are looking for a good flat shooting load at 100 yards so you can move/adjust your cross hairs after building dope on other loads that require you to to do so at the same or longer distance. Am I close?

[GhostHawk]

OP, what you are asking is one way. Another would be to work up a single load, get to know it and what it does at different ranges. Doubt induced by wondering " how much hold should I have for that deer over there?" well it does not do good things for accuracy or confidence. Both are IMO essential in deer hunting.

Just supress that desire for a "hotter" load. Work up one solid load that he can live with, and hit with, offhand, at a variety of ranges.

You'll both be happier in the long run.

[35 shooter]

One way to do that without touching the turrets(providing both loads are in line on a vertical plane) is to sight in with the hotter load and then turn the power level down on the scope for the lighter load.

With a 3x9, sight in with the hotter load at 9 power then turn the power down to say 3 or 4 and use the tip of the lower post for the lighter load.

Many times this has given me a zero at 100 yds. that works with both the heavier and lighter load. Simply use the crosshairs for the heavy load and turn the power down and use the tip of the bottom post for the light load.

I have one load for my whelen@2200 fps. and the same boolit with another load and powder @1275 fps.
Sighted in 2" high @ 100yds. with the cross hairs on 9 power with the hotter
load it is dead center @ 100 yds. on 3 power with the light load using the tip of the bottom post.
I'm ready for small or big game with a simple twist of the power ring.

This works for me, but #1 on Ghosthawks advice too...much simpler to just deal with one load at a time.

[newton]

Thanks guys. I knew it might sound confusing, and one of those questions that makes people scratch their heads..... duckey, yes, what you said is what I am asking about.

Good advice, but I think that I have not asked my question the right way still. Really, the question is more about bullet trajectory with different loads, and if people have found it best to set their scope to one load or another. I was not sure what part of the forum to ask this question in, so I figured load development might be the place.

I would go with the first suggestion, but I don't think that it will fit the bill for my application. I would like to have a 100 yard plinking load. I truly do understand that there can be confusion with two separate loads, and keeping just one load for both applications would be ideal - but the whole idea is to have a less expensive load to shoot a lot of and a more powerful(and expensive) load to hunt with. I do like the idea of the scope magnification, and might be the ticket with this - but that also might be confusing. I still think there is a way to do it, but my brain is not in gear yet.....

Here is one way to put it. I have two separate loads for my 30-30. I have a Williams FP peep on the receiver. It has lines on it and I know which one to put it on for my hunting loads, and which one for my light plinking loads. Real easy to move up and down, but there is no "zero" per say like there is for a scope.

My main reason for the question is deciding which load to work up. The hunting, or target. So my first thought, and probably the best, is to zero for the hunting. But then I got to thinking that maybe that's not the best - even though at this point I am confusing myself because you can think about your shots target practicing(adjusting scope based on dope) but you need to be able to pull and shoot when hunting(as has been mentioned).

One thing that I was thinking about last night is if there was a ballistics calculator out there that lets you see the trajectory of different loads, but keeping the same zero. All the calculators I know of are based off the "zero range" changing with each load. So what got my thinking - and the basis for the original question - is wondering if a 100 yard zeroed plinking load might give me a zero of 150 or even 200 yards with a full power load. I know that I could just "find out" by shooting them, but I also know that it can be calculated - I just don't know of the calculations.

So did this just muddy the water even more, or am I making it even murkier? I apologize if this is too confusing, I sometimes have confusing thoughts.

[fecmech]

Simply mark your elevation turret with two different sharpy colors. One for your hunting load zero and the other for your 100 yd target zero. I do it all the time with my lever gun moving between .38 spl loads and .357 mag loads.

[newton]

Yea, I think I will just zero for hunting and move turret for target if needed. The turret is marked, and once zero is found you can unscrew the turret and put it on the zero mark.

Really, my quandary would be solved if I could find a ballistics calculator that keeps a zero point with one load/velocity, and lets you see where the zero/trajectory would be if you increased the velocity.

What my goal would be is to have the hunting load set at a ~150 yard zero which should give a point blank range of ~200 yards, and then have that be close to a 100 yard zero for the lighter load. Not sure if that will actually happen, but that's what I am curious about.

All in all, this is just a curiosity question. Its raining here, don't have the gun yet, and not anything else to do but contemplate stuff like this.

[newton]

closest i am coming to finding my answer is a point blank range calculator. not exactly what I need, but getting close.

http://www.shooterscalculator.com/point-blank-range.php

[rr2241tx]

I think there are some good solutions here. I really like fecmech's solution because each load can be zeroed at the optimum velocity and both the windage and elevation marked. As long as one remembers/records the color code then there's no need to hold off nor accept poor accuracy from the cast load. I plan on using this idea with my 45-70s where I have half a dozen cast loads and two jacketed loads, none of which hit in the same place.