Any suggestions on how I figure out about my Scopes Adjustments?

[ConnorExum]

So this Saturday I was out at the range shooting my favorite target: a reactive pice of metal about 3.5x3.5 by .5 inches thick at 500yards with my Howa1500s Varmint rifle. Now, of course 500yards isn't too far really. But my Tasco scope,trashco is more like it, I so need a new one)seems to go from 1 Click 1/4" at 100 yards to about 2 clicks or maybe 3 clicks per turn of the elevation or winddelfection knob on the scope. Is there any way I check to see of the threads on the knobs are wornout and thus giving me the erradict adjustments. I have to say one week I'll zero it and it will hit the plate 20-30 times out of 50 shots and the next time I'll shoot 100 rounds and hit like 3 times. There seems to be no telling what the adjustments will do with this scope it's like being an alchemist and not shooter...

Help please.

Connor R. Exum

 

[ArtinNC]

conner,
Try "Big Game Info" they have a ballistics calculator that I think is pretty good. The first time that I ever shot 600yds I used it and hit 5 for 5 clay birds using it . Art

 

[ConnorExum]

Conner
The scope is probaly not the problem.Hitting a 3.5 inch square at 500 yards is very do able with a good rifle but just because you can do it doesn't mean that it is always going to happen.
The wind and updrafts and down drafts will help determine your shots for the most part.When you read about guys averaging 3 inches at 600 yards with a 6BR for 6 targets that is good shooting.Remember they aren't hitting a 3.5 inch gong but a very large sheet
of paper and the groups will be in many different places for 5 shots each.They will also be shooting heavy for caliber bullets which don't get blown around as much as say a 220 Swift shooting 55 grain Sierras.

If you give us a little more detail on your combination and exactly what you are seeing it would help us decide if indeed the scope has a problem.
Lynn

I've been shooting mainly Blackhills 52grain Match loaded ammo. I don't have the stuff for reloading yet. I can't shoot a bullet over 60grains because of my barrels appauling low twist rate of 1:12. So, the wind factor is huge in anything over 10mph. I've tried to get in contact with Blackhills about their 52grain Bullets' BC so I can use JB Ballistic Calculator and develop a better drop chart. They haven't repsonded as of yet. Right now I'm using a value of .223-.224 for the BC of the 52grain Flat Base bullet at a Muzzle Velocity of 3250fps. I need a chronograph too but hey money is short as I'm a college student.

The conditions at the range are rather predictable actually, as the range itself is nestled inbetween to large hills. So that acts a great wind buffer. However, to shoot 500 yards, I have move the target up a steep bank that is about 15 degress in elevation already and the area where the target can be placed is a rectange patch about 30 feet long and 10 feet wide with trees on each side of it. The wind isn't usually all that bad at this area because of the trees acting like a buffer. I usually have a wind flag at 200 yards, 400 yards and smaller wind flags made of surveyors flag tape on the target's legs itself. This way I can see the wind at the target itself. Since I live in Kentucky the air tempature around now is about 80-95 degrees but since most of the range is grassy and the higher up on the bank I shoot the greater amount of vegation is present I don't seem to have serious mirage issue as the target only gets a bit hazzy not the classic wet window in heavy rain storm look. So I can usually shoot through the mirage with no problem. However, I do know that the mirage does alter the prespective of the target in my scope and could account for some problems. I do have a Mirage Band on order for the rifle right now.

The reason I believe the scope is at issue is that impacts seemed to be so varied. I can see the impacts because area is soft soil where I place the target in a crater on the hill. This allows me to adjust usually with some accuracy the rifle's scope without having any problem or at least it did from 300-400yards. Now at 500yards the bullet is actting strangely even on clam days. The bullet and my point of impact seem to vary from shot to shot moment to moment I'll hit the target 3-4 times then nothing for 5-6 more shoots with the bullets seeming going every which way from the impacts. As I read all my flags before shooting I do know what the wind is doing and dope it as best as possible. My guess is this that the scope has an error in it's adjustments perhaps excessive backlash because when I turn the knobs the threads feel as if they have play in them and that on click easily turns to two or three with one turn of the knob. This coupled with the excessive wind deflection at the 500 yard range from using 52grain low BC bullets is the reason I can't hit the target well. I figure if I can narrow down the varibles one by one I can determine if it's the rifle, bullets, scope or me... Well a good portion of the time it's probably just me but the other 20 percent of the time it's the equipment I feel...

Perhaps, now you can shed some light on this issue for me?

Connor R. Exum

 

[jb1000br]

shoot a group on the bottom of at least 30" of paper at 100yds.

click UP at least 20MOA or 30 if you got it, and shoot another group

measure the distance between group centers and divide by the clicks it took you to get there.

JB

 

[M700]

jb & gunamonth are tracking. Now let's see if your scope is.

We've got to perform a "box drill", or two. Set up a relatively huge target at a mere 100 yards. Get the rifle all snugged down tight. Sandbagged, bipod whatever. Use good, accurate ammo. Limit your coffee intake. It should be a relatively calm day. You want to eliminate as many variables as possible.

Start at the bottom left of the target. Shoot a three-shot group.

Add 5 MOA,20 clicks if you have 1/4 MOA adjustments) elevation. Shoot a three-shot group.

Put in 5 MOA right. Shoot a three-shot group.

Take off 5 MOA elevation. Shoot a three-shot group.

To left 5 MOA, shoot a three-shot group. This one SHOULD land right back on top of your first group. You should have three shot groups at each corner of the "box" you've drawn with your rifle, measuring about 5" apart.

Now - to really test the scope, try it again, with 10 or 20 MOA changes instead of the little 5 MOA change the first time.

By doing this you're checking the way the scope tracks; up, down, right and left. I find the 5 MOA adjustments get me a fair picture, but the 10 or 20 MOA adjustments are even better. You should end up with nice symetrical square boxes, with 3-shot groups at each corner. If not, your scope has tracking problems. You can do variations of this drill, going higher & lower, or farther left and right, but start with the basic box drills to check things out.

Hope this helps. I've seen mid-high priced scopes have problems with this, let alone lower-end models. Regards, Guy

 

[ConnorExum]

shoot a group on the bottom of at least 30" of paper at 100yds.

click UP at least 20MOA or 30 if you got it, and shoot another group

measure the distance between group centers and divide by the clicks it took you to get there.

JB

Thanks for all the Help.

 

[ConnorExum]

Jason's got you going in the right direction. As long as you've got that big piece of paper up there you might want to try something else also.

After you do the way up, way down in the center of the paper, try doing the same thing with a lot of left and then right horizontal cranked in. You may find that at far left and far right the amount of vertical you get per click is less than it was in the center, especially as you get near the end of travel. What happens is the erector tube comes in contact with the main tube so the amount of vertical adjustment you get is less per click. You may also get some horizontal that you didn't want along with it.

This happens even with some of the very popular, high $ scopes. Ideally you'd like to have the scope mounted so the reticle is centered in the tube at the longest range you normally shoot. It avoids this problem and minimizes spherical abberation at your longest range where it's most important.

Manufacturers claim +/- so many MOA verticle and horizontal. Sometimes it's one or the other but not both at once.

Will do.. thanks for the help.

 

[ConnorExum]

shoot a group on the bottom of at least 30" of paper at 100yds.

click UP at least 20MOA or 30 if you got it, and shoot another group

measure the distance between group centers and divide by the clicks it took you to get there.

JB

Thanks alot this should answer some of the questions I have...