Scope elevation out
wolfpack
Member Posts: 1,251 ✭✭✭✭
Purchased a pre 64 model 70 in 300 H&H off GB with an older Leupold Vari X II already on the rifle. Went to the range today with factory Nosler 180 gr Accubonds. Rifle was shooting low at 50 yds, so I started adjusting elevation and shots were tracking well but ran out of adjustment. Made a little more than one full turn on the elevation before it ran out of adjustment. Plenty of windage adjustment but rifle was only about 1/2" off on the windage so didn't mess with that. Redfield base with dovetail front and windage rear, rings look to be high but can't tell the manufacturer. Everything solid and locked down on bases and rings, nothing loose. Rings look to have been lapped and no marks on the scope body at all, scope fits well in the rings. Rifle is still 8" low at 100 yds with no elevation adjustment left. Spoke with Leupold and am sending the scope in to have it checked. Any other ideas on why it might be shooting low? On the positive side the rifle functioned flawlessly and I believe it has potential to be accurate if I can get this elevation corrected.
Comments
If it turns out not to be a scope problem the base may need to be shimmed. You would be surprised how much a thin shim under the rear of what I assume is a one piece base will raise your point of aim. Being a one piece base this will angle your scope to the point of aim without putting stress on the scope itself like would happen with 2 piece bases. Best of luck. Bob
Another option would be to switch out your rings with Burris Signature rings and install offset posi-align inserts to move point of aim and allow you to re-center your scopes elevation adjustment. I have them on a number of my rifles and have never had any slippage or zeroing issues
Yes it is a one piece older base with slotted screws, the rings may be newer as they have torx screws. Scope is an older Leupold vari-x II 3-9x40. It has 3-9 stamped on the dials which I have not seen before, also there are no click adjustments, the dial is smooth when you turn it. Leupold tech said it was a micro adjust friction dial. I have another scope, a 2-7x32, which I know is good and I may put it on and see if it adjusts in elevation. Only thing is ammo is so expensive that I don't want to do more than what is absolutely needed.
I would optically or mechanically center the scope reticle.......before coming to any conclusions concerning the vertical or horizontal adjustments.
Hope this helps.
First of all, beg or borrow a collimator. That saves a lot of cartridges!
I have a couple of those old Winchester .300's. I took some measurements of my set-ups: From the center of the front ring to the screw for the rear of the base is 4.25". Doing the math, indicates that a .010" shim under the rear of the base would raise the point of impact @ 100 yds. 8.47". That would put your shots about where you want them but you are still all out of elevation. You can add more shims but that's not good, either; eventually something will bend. The Burris posi rings is probably the easiest and best solution--I have not used them, but as "carbine 100" said, I've heard that they work well.
As an aside, I've found with my rifles, there's a head space problem in that the cartridge manufacturers are a bit careless about the dimensions of the case belt. Since the cartridge is supposed to head space on the belt, that's an issue. It's no problem if you don't intend to reload, but if you do, the cases start to separate on the third firing. I get around that problem by expanding the necks of new cases to 8mm and them carefully size them back down untill the bolt closes with some resistance. The cases will now head space on that long sloped shoulder and, being careful not to set the shoulder back when re-sizing, the cases last as long as any other cartridge.
You have a great rifle and scope with a classic cartridge. Good luck with it.
You may want to lap the rings also.
Update on the scope. I ordered the Burris signature rings and a set of posi align inserts. Installed a plus 10 in the back a minus 5 in the front to give me 15 thousandths of elevation. They worked wonderfully, actually had to adjust turrets down to sight in, quite a bit of elevation adjustment left in the scope, Rifle shoots sub 1" groups at 100 yds now. The inserts really seem to get a good grip on the scope tube also. Fine job Burris.
Thanks for following up. It's always nice to see how a problem was resolved.
As Ambrose says: First of all, beg or borrow a collimator. That saves a lot of cartridges!
and time
Good to see you got it going and doing it correctly. You need to consider eventually getting a bore sighter. I use a laser type at about $50. I use it on everything from crossbows, black powder guns, pistols, rifles, shotguns. I install and change out scopes and site in (shoot in) for people. Also keep in mind that a good rule of thumb is .001 change will equal about 1 inch change per 100 yards of shim. Before shimming or using the Burris signature inserts, I center both the windage and elevation and then use the bore sighter to see how many inches is required at 100 yards to get on the target then shim or order the Burris inserts accordingly.
I also use the Burris signature inserts on some of my more expensive scopes just to keep the scope tube from getting marred. When using a matte finish aluminum scope tube and steel matte finish rings, I've seen the two gall/erode together and leave pits in the aluminum scope tube after about two years of use. Burris inserts will leave the scope tube non-marred.
I seen some nice custom Mauser rifles that were out several inches in both elevation and windage and have to go to the Burris Signature rings and inserts with good results. (mainly due to the base screw holes being drilled off center) You would think that others would also make (copy) signature type rings as they do not mar the scope tubes like the Millet windage adjustable and others that will bend and warp and scope tube. Burris has a good idea with such and lots of people not even aware of such. Also with the plastic inserts no scope bending and marring.
At $1 per shot or more a bore sighter will save lots of time and $'s fast. (and you are shooting expensive ammo yourself on the 300 H&H)
Also you will find that the higher the power on a scope the less range the windage and elevations adjust.
AND most generally the Leupold scopes are ok. Your 2x7 would probably have got on target due to having more adjustment range but the elevation adjust still off center.
Also I suspect if a scopes adjustment is left at the end of it's adjustment range for long period of time that a erector spring is fully compressed and more likely to become weaker when left in this position for long period of time and the scopes adjustment is more likely to become erratic or not hold zero if re-centered after long period of time. (scope adjustment become erratic and not track properly.
Buy your wife a bore sighter for Xmas.
I’ll wager it’s the rings and not the scope