Anyone have any tricks for adjusting POI consistency across multiple loads?

[300magman]

I don't have a real pressing need to figure this out other than tooling around at the range with some fun loads, but I've noticed that my Marlin 45-70 shoots to DRASTICALLY different POI with different loads.
I was expecting vertical differences to be more spread than horizontal as I switch from subsonic to mid-range to top speed loads but I was surprised to find that the horizontal is just as extreme, to the point that at 100 yards they are going off paper.

Again, my hunting load is My Default Load so that is where I pretty much leave the rifle zeroed, I'm just curious if there are any adjustments I could try with the other loads or even tweeks I could make to the rifle, to try to bring the horizontal differences more in line so that when I'm playing with some reduced loads at the range I can possibly just get away with dialing for vertical shift and leave the horizontal adjustment alone.


Oh, One word of advice to those with a 45-70 and family -> never let the wife/gf/ or kids try it out with 400gr pills at 800 fps. The recoil is SO light yet it leaves such craters in the berm that they will forever bug you to bring the "big gun" for them instead of the 22lr every range trip from then on.

 

[BountyHunter]

The 45-70 is kind of unique in that it has three specific load levels of ammunition and in the reloading manuals.

Trapdoors and like
modern lever actions and Siamese mauser
Modern strong break actions like ruger #1 etc.

If you are mixing those loads they run from 2350 with the Hornady 325 FTX to the 500 grain lead at 1400. No way to get similar POI like that.

 

[300magman]

The 45-70 is kind of unique in that it has three specific load levels of ammunition and in the reloading manuals.

Trapdoors and like
modern lever actions and Siamese mauser
Modern strong break actions like ruger #1 etc.

If you are mixing those loads they run from 2350 with the Hornady 325 FTX to the 500 grain lead at 1400. No way to get similar POI like that.

Well, your right about 3 load levels, just with my Marlin those 3 levels are:
Subsonic (purely range fun)
Roughly "Trapdoor" equivalent (range fun / practice)
& Near max for Modern Lever Actions (Hunting)

However, I am NOT comparing the full spectrum of projectiles. I'm just using different velocities with the same bullet.
Though I have tried this with both a 300gr and a 400gr with similar results, though the 300 gr did move around with changing velocities somewhat more than the 400 did.

 

[pods8]

Maybe someone has some black magic up their sleeve but it seems to me just figure out the clicks in both planes from your zero load and note it down. What is your objection with making horizontal clicks?

The rifles I shoot aren't as extreme of a movement as you are talking (off the paper horizontally at 100yd) but there is certainly movement, often a few MOA worth when going between loads (different bullets factor in too).

 

[justgoto]

Again, my hunting load is My Default Load so that is where I pretty much leave the rifle zeroed, I'm just curious if there are any adjustments I could try with the other loads or even tweeks I could make to the rifle, to try to bring the horizontal differences more in line so that when I'm playing with some reduced loads at the range I can possibly just get away with dialing for vertical shift and leave the horizontal adjustment alone.

If you use the OCW load development method, it takes into account the horizontal deviation you are seeing.

When I use the Audette Ladder Test method of load development, I also account for the horizontal deviation, something that most shooters have been told to ignore.
Nowadays, when I develop a new load, I hold for wind during the ladder test. Then, when examining my target, I choose the nodes that group more toward the center. Now, all my loads are centered windage-wise.

 

[300magman]

Well, I can always experiment a bit. I'm not opposed to playing around with a grain more or less powder on the reduced loads to see where it takes me.

I was also talking to a steel silhouette shooter who had the forward stock on his marlin lever in 357Mag epoxy bedded to make continuous contact with the barrel for the entire length of the forward stock. He claimed it made a noticeable difference in his groups. . . I might try that, if it is possible without permanently gluing the stock on; though I might first just try half the length. Perhaps it will favorably stabilize the barrels harmonics across the full range.

Any input on whether or not it would be worth experimenting with adjusting the seating depth across the Very Narrow window that the bullets seating bands might allow for, or would such a small adjustment typically not yield much of a change in the load considering the bullets are already no where near the lands and a few thousandths of an inch closer wouldn't even equal a 1% adjustment.

 

[pods8]

You are already going to have to may vertical clicks right? As previously asked what is the issue with just making the horizontal ones too? I hunt with Barnes bullets and that is what my scope is zero'd for but those would be spendy lots of target work so I also have a cup/core target load for each of my rifles and know the adjustments (which requires both vertical and horizontal) to switch back/forth. On a good scope I don't see the issue dialing back/forth.

As for the epoxy its "bedded" not glued, you put release compound on the barrel when doing so, if you were so inclined to bed the barrel. No comment from me on if that'd help you at all, I free float my guns.

 

[300magman]

You are already going to have to may vertical clicks right? As previously asked what is the issue with just making the horizontal ones too? I hunt with Barnes bullets and that is what my scope is zero'd for but those would be spendy lots of target work so I also have a cup/core target load for each of my rifles and know the adjustments (which requires both vertical and horizontal) to switch back/forth. On a good scope I don't see the issue dialing back/forth.

As for the epoxy its "bedded" not glued, you put release compound on the barrel when doing so, if you were so inclined to bed the barrel. No comment from me on if that'd help you at all, I free float my guns.

Perhaps I am taking you the wrong way, and my apologies if I am, but your posts read as though they have a very condescending tone to them.

Yes, I understand it is not a terrible amount of work to dial on both planes, though with a typical hunting scope you do have to remove the caps and count clicks, so its not quite as fast & easy as using the target tactical turrets with zero stops.

I was mainly asking the question, just to see if there was any knowledge out there that I had not yet acquired, I like to learn new things when I can, and I have no problem tinkering with a theory just to see where it can take me or what I can learn.

Also, I know release agents let you epoxy bed rifles without making a permanent bond, but I also know a principle exits whereby a stock can be accidentally glued on by way of a mechanical bond depending on the shape of the portion of a rifle being bedded.
As it has been a long time since I have taken the forward stock off of my Marlin, I don't remember exactly what it looks like under there, but I know I would check before setting my mind to the project and going out to get supplies.

 

[pods8]

Not trying to be condescending, just not following your thought process. You will regardless have to make a vertical adjustment in your mind correct? If so I really don't see the difference to do horizontal too. Note I don't run target turrets either, all mine are hunting scopes under caps too BUT they are marked dials so I don't need to count clicks specifically. Do you not have markings to repeatedly go between? I presume you'd only be playing around with light/practice loads on the range with ample time?

Long story short I personally don't know of methods to try and force a POI between different loads so I was approaching it from a method I find works fine for me.

As for mechanically locking when bedding it occurs when something wider is below the line of the bedding, thus it can't be pulled out. I don't know what that gun looks like under the stock with that second tube but if it is two stacked tubes (barrel over the mag) you would likely need to fill in the area where then tubes meet with clay out to the diameter of the tubes IF you were so inclined to bed it. But I have no idea how well bedding the magazine tube, which is mostly what would occur there, would do in for your goals.