How do you manage different rounds out of the same scope/gun?

I was thinking of putting this in the precision rifle section, but this is likely something you have run across.

When I'm developing a load, my scope is set to whatever my last series was. So- usually it's pretty much 'on', and then I go through my OCW and find the best group. But, this group won't be at the bull, it's almost always a little higher or lower due to bullet weight and left or right due to harmonics.

But let's say I'm not developing a load, I just want to put some rounds down range and make some clovers. But- I might shoot some 165s, or some 150s, or even some subsonics. How do you manage the scope settings for different bullets? I only have one zero stop, so everything else would have to be based off that. Or- do you just take a couple of sighting shots, adjust and then shoot? This does not work well in my 308 because of the speed difference between supers and subs. I can't remember where I set it last, so I might be off the target when I start shooting.

I'm hoping there's a 'duh, stupid', answer so please educate me.

I have two loads for my 308.
175gr supers at 2650fps and 200gr subs at 990fps. I know the dope for changing between them.
I sometimes swap over to cheap 150gr for banging steel. I don't really need to adjust anything to bang plates at 250yds with those.

Shooting groups doesn't require me to hit the bull. All I need is an aiming point.

Just thinking out loud here. Keep notes on the relative change between loads. Find the load that is the highest POI, and set your zero stop for that. Changing the turret for different loads would then be easy to do.

balistic programs like applied balistics have a zero offset in them. So zero for one load and then for each different load put in the zero offset then the program will tell you the right dope without changing the zero.

For testing/working up loads. I don't even see the need to bother with moving the scope. Adjusting POA for every new load seems tedious and like chasing my tail.

Keep the POA exactly the same for each new test group. I don't care if it's two inches low, 3 inches right if it makes a cloverleaf.

If that's my load. Then I adjust the scope to it. I typically strive for anaccurate as I can be load then try to mimic that with as cheap a load as possible. So I have practice/plinking round with the same POI as my "supreme" rounds.



If you end up with multiple loads you like running in one setup. Just write down your dope for each. So you know where to adjust for each one. Go back to your zero stop. Then adjust to the round your using that trip

If you use an app like Strelok Pro (awesome product by the way, get the PRO version), you can input all of your data for multiple loads per rifle. For each load, you can input a 'zero offset' that will then automatically apply to your solutions.

For example, my handload 6.5CM is my primary load that I've zeroed at 100 yards. So the 'zero offset' is 0.
A commercial load for that rifle requires 0.3MIL adjustment to hit the bullseye at 100 yards. The "zero offset' in Strelok for this load is 0.1MIL.

So, a 700 yard solution for the handload may call for 5.9 MIL of elevation with the handload and 7.2 for the commercial. IOW, it does the calcs for you.

screen shots showing my handload and the commercial load with the offset entered:

If you are just shooting groups, why care if the bullets group at your point of aim?

JBoyette said:

If you are just shooting groups, why care if the bullets group at your point of aim?

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Sorry if I wasn't clear- I'm not just shooting groups, I do that for building loads to test. When I get an 'Accepted' load, I make a bunch of them, knowing they'll group well. And using that one group, I can zero my scope to hit bull every time. But- a different load/weight will not hit the same location, and I like shooting steel at distance. the extreme case is super and subsonic- that's not just a different offset from bull, it might not even be on paper without adjusting the scope.

Sas quatch said:

Sorry if I wasn't clear- I'm not just shooting groups, I do that for building loads to test. When I get an 'Accepted' load, I make a bunch of them, knowing they'll group well. And using that one group, I can zero my scope to hit bull every time. But- a different load/weight will not hit the same location, and I like shooting steel at distance. the extreme case is super and subsonic- that's not just a different offset from bull, it might not even be on paper without adjusting the scope.

Click to expand...

Ok got u.

I dial the offset and just add the dope from that offset.

Example.
1 moa high, .75 moa right
Dial that on and do dope it from that point.

I have colored marks on my turrets for different grains

Tim said:

screen shots showing my handload and the commercial load with the offset entered:

View attachment 217922 View attachment 217923

Click to expand...

I've just bought the Pro version.

My plan is to zero my rifle with my fastest round, and then everything else should hit lower than that? That way I can keep the zero stop, especially as I'm going between supers and subs (300 BLK bolt gun). I'll give it a try today.

Sas quatch said:

I've just bought the Pro version.

My plan is to zero my rifle with my fastest round, and then everything else should hit lower than that? That way I can keep the zero stop, especially as I'm going between supers and subs (300 BLK bolt gun). I'll give it a try today.

Click to expand...

That is what you would think, but it also depends on the barrel harmonics. At the zero distance, there may not be much difference in bullet drop, and barrel whip could be significant. At longer distance bullet drop will be more significant.

Sas quatch said:

Sorry if I wasn't clear- I'm not just shooting groups, I do that for building loads to test. When I get an 'Accepted' load, I make a bunch of them, knowing they'll group well. And using that one group, I can zero my scope to hit bull every time. But- a different load/weight will not hit the same location, and I like shooting steel at distance. the extreme case is super and subsonic- that's not just a different offset from bull, it might not even be on paper without adjusting the scope.

Click to expand...

When you get an accepted load what conditions have you tested it under? Hot weather, cold weather, distance, etc.? How many groups have you shot until it is accepted? Suggest you use your method to find an accepted group but do not load a batch until you have tested it in all conditions. Once you find that load don't go overboard in batch loading for it, sure as you do another load will pop up and better it. Only load batch rounds for a match, serious shooting session or when TSHTF.

Dial your scope zero to match that preferred load. Make a detailed dope card for it. All other loads should be shot at the same zero with the information on wind and drop on your dope card. I wouldn't mess with recording loads that are outside of a minute or two. This includes any factory rounds that you might be inclined to shoot.

Not trying to bust your chops but I've pulled hundreds of bullets from rounds I thought were great after finding something that shot better. I'm a firm believer in having at least three loads with different powders that group close to each other. You never know when your preferred powder/primers will become un-obtainable.

Sas quatch said:

I've just bought the Pro version.

My plan is to zero my rifle with my fastest round, and then everything else should hit lower than that? That way I can keep the zero stop, especially as I'm going between supers and subs (300 BLK bolt gun). I'll give it a try today.

Click to expand...

That should not be the basis. The fastest round may not be the most accurate. The round with the best ES/SD may not be your most accurate. Don't give up accuracy for speed. YMMV

Well, from the discussion, I don't see a solution- Looks like I will burn rounds sighting in when I change known loads. From the original post, I was hoping for something I was missing but looks like there's no an easy answer.

Sas quatch said:

Well, from the discussion, I don't see a solution- Looks like I will burn rounds sighting in when I change known loads. From the original post, I was hoping for something I was missing but looks like there's no an easy answer.

Click to expand...

In my humble opinion, there is absolutely an answer. Use the offset approach I mentioned.

the posters above, again in my opinion, are way overthinking things.

I regularly shoot matches and steel with different loads. The load I choose each time depends mostly on my purpose that day. A lot of the matches I shoot have 3-4 MOA steel, so I’m happy burning through factory ammo. If I’m going for <1MOA steel or shooting groups I use my hand loads.

Applying the zero offset to your known DOPE couldn’t be easier.

for the “weather” variations mentioned above, keep good notes and learn your DOPE. Or do like 99% of competitors and use a weather station (Kestrel, Windmeter, internet) and an app to calculate your solutions in real time.

long range shooting does require knowledge , skill and experience....but if I’ve learned 1 thing, it’s that it’s nowhere near as complicated as some choose to make it.

Hi Tim- yes, your answer made a lot of sense- which is why I bought Strelok pro which keeps the offsets. I still need to have my 'base' load by which to build the offsets.