Using the same scope

[dombra]

Dear All,
before I start cranking knobs I though I might ask first -
My ? is

does anyone have scope set on shooting 308 cast @100 yrd then cranks the setting down to shoot a J bullet- Do they make ascope thatll do that?
Many thanx

[NVcurmudgeon]

There's not really a simple answer to that question. Most of my cast boolit rifles have iron sights and are dedicated cast shooters. My .35 Whelen is scoped and when it is sighted in three inches high at 100 yards using a 250 gr. J bullet, mv 2600, my favorite 215 gr. cast load, mv 1700, will hit about eight inches low and eight inches right at 100 yd. About all I can do is keep a note in my range notebook so I can easily move between the two loads. In practice, I keep this rifle sighted in for the cast load, and resight only when I am planning a hunting trip. With such a big difference between full power J loads and moderate cast loads, windage may change as much or more as does elevation.

[44man]

Thats the way to do it! Sight in with the load you shoot most, then sight in with the other bullet and record the clicks. Then you can move back and forth between loads as you need to.
The only other thing is to get a scope with target turrets. You still have to record changes in a note book but you don't have to unscrew caps and hunt for a penny or something to adjust with.

[Maven]

dombra, I do this several times a year with 3 of my rifles, but as already mentioned, it helps to record the elevation (and windage?) settings you use most often. Option #2 is to do nothing to the elevation adjustment and simply shoot your CB load at a given aim point/target, but place another sheet of paper/"target" say 6" to 14" above it to record your j-word bullet results/groups. Btw, it helps to keep a few pennies in your shooting box in case you need to change the 'scope settings.

[Lloyd Smale]

ill sometimes tape scope settings for differnt loads right on the stock. Its ugly but effecient

[jhalcott]

You COULD buy another scope and set of rings for the OTHER kind of bullets. I have the Weaver style bases on most of my guns. A quick change over is easy and doesn't need any adjustments for testing work.For actual hunting or fine target work a minor adjustment MAY be needed. When I go out of state for hunting I will sight in 2 scopes on the gun. One goes in my pack the other on the gun. Scopes and slippery ,rocky slopes do not get along!

[dombra]

Thanx for the feedback gents

[454PB]

I can go from shooting cast to shooting jacketed without much trouble, but after shooting jacketed, my cast loads don't shoot well until the bore has been scrubbed clean of any jacket fouling.

Other than that, scope settings can be reset, recorded, adjusted, and repeated successfully.

[C1PNR]

Not all scopes will reliably repeat POI back and forth. I have a couple of older scopes that just wont do it.

Test your scope by moving, shooting, moving back, shooting, moving, shooting, etc., several times until YOU are satisfied the POI moves to where you expect it to be.

[44man]

Yeah, thats a major problem with a lot of scopes. Lately I have not found any that even move the POI the amount stated. Leopold is still perfect and the old, old Weavers are still the best. Even my Burris moves different then stated and the windage is not the same as the elevation.
But the small amount needed to adjust from one boolit to another should be repeatable.

[wiljen]

I remember one of the NRA mags years ago advocating a box test for scopes. Fire once, move 8 clicks right, fire again, 8 clicks down, fire again, 8 left, fire again, 8 up, fire again etc. They suggested 3 round groups at each position so you should get 4 3 round groups in a 2 inch square. I'd bet that most scopes can't begin to do that these days.

[Ricochet]

There's often some backlash in the scope so that when backing down the setting you can't simply take off the same number of clicks you put in. Yyou may have to move back more clicks, then turn some back the other way to get where you were, so you're always approaching the setting from the same direction.

Sure is easier with military open sights!

[S.R.Custom]

As noted earlier, Leupolds are less ornery in this respect, but some of the lesser scopes are horrendous. I frequently find myself having to "tap in" an adjustment by rapping on the scope turret with the handle of a screwdriver. Makes you wonder just how many of those flyers are caused by recoil induced scope fluctuations... :???:

[44man]

A big problem is the inner tube that the adjusment screw touches. If putting too much adjustment in one direction, it will effect the other. Elevation can effect windage, etc.
The tube should have flat spots at the adjusment screws.