PDA

View Full Version : Scope issues or am I just stupid...?


DannyInSoCal
11-01-2010, 3:27 PM
Zero'd the used Bushnell scope I picked up at 30 yards -

Backed out to 100 yards and ran out of adjustment before it was zero'd.

Removed scope - Remounted to be sure it wasnt moving -

Started over - Same results.

(6.8AR fired with a bipod and range bag supports)

It's just a rimfire cheapo - But it should still work for 100/200 yards....

???????

Thanx, DISC

xibunkrlilkidsx
11-01-2010, 5:29 PM
shooting high or low?

Jonathan Doe
11-01-2010, 5:39 PM
Rimfire scope may not have enough adjustment. Try counting the clicks from all the way bottom to all the way top. I am certain they have a lot less clicks than some decent centerfire scopes. However, I have never tried, and I cannot be sure.

killshot44
11-01-2010, 5:51 PM
Combination of Rings/mounting height and minimal internal elevation adjustment.

G-forceJunkie
11-01-2010, 6:31 PM
I think your problem is how you zeroed. i think the 30 yard zero when the bullet crossed the sight plane on the way up. Try shooting 100 yards with your 30 yard zero before turning any knobs. It should only be 3-4 inches low since the bullet will be recrossing the sight plane around 60 yards. It should work for 100 yards, 200 I doubt it without an angled base or a scope with alot of internal adjustment. Start with a 50 yard zero and go from there.

HighLander51
11-01-2010, 6:35 PM
All center fire rifles have two zeros because of the parabolic trajectory. If you zero your 6.8 at 30 it should be zero again at about 340 yards. It will be about 8" high at 200 yards, zero again at 340 and about 8" low at 400 yards. You cannot re-zero at every range you choose without changing both zeros. It's called a window. You have to decide how big a window you want, for example, a 10" window means a 40 yard zero, again zero at about 270 yards, but this setting will get you about +5" at 150 yards and about -5" at 320 yards therefor the 10" window. So this setting would allow a +/-5" shot by holding center to 320 yards. So in theory, a center hold at any distance between contact distance and out to 320 yards would hit a 10" target. It also depends on scope height over bore axis and actual loads.

DannyInSoCal
11-01-2010, 8:43 PM
All center fire rifles have two zeros because of the parabolic trajectory. If you zero your 6.8 at 30 it should be zero again at about 340 yards. It will be about 8" high at 200 yards, zero again at 340 and about 8" low at 400 yards. You cannot re-zero at every range you choose without changing both zeros. It's called a window. You have to decide how big a window you want, for example, a 10" window means a 40 yard zero, again zero at about 270 yards, but this setting will get you about +5" at 150 yards and about -5" at 320 yards therefor the 10" window. So this setting would allow a +/-5" shot by holding center to 320 yards. So in theory, a center hold at any distance between contact distance and out to 320 yards would hit a 10" target. It also depends on scope height over bore axis and actual loads.

The best explanation of zeroing I've ever read. So what I thought was a decent scope to go a few hundred yards - Seems like I made the wrong choice.

Looks like I'll just use the iron sights for the turkey shoot on the 7th - And figure out a decent scope afterwards...

Thanx, DISC

BKTJ
11-01-2010, 9:10 PM
My money would be on the cheap scope being the problem. I have never had good results with cheapie .22 scopes, however I have run $100 BSA scopes and had very good results.

HighLander51
11-02-2010, 7:25 AM
One of the note worthy lower cost scopes being used in 3 Gun matches today is the Simmons Pro Diamond run by Benny Hill from Texas. These are about $80. Actually more important that a scope is a good trigger for your AR. Most factory triggers are crap, too heavy and sloppy for good shooting. Prices range from about $120 to $300 plus. Here are a few, Jard, Chip McCormick, JP, Accuracy Speaks, RRA 2 stage, Timney, Jewel, and so on,

http://www.brownells.com/.aspx/cid=798/k=/t=S/mfg=/Products/AR-15-Triggers

DannyInSoCal
11-02-2010, 8:02 AM
One of the note worthy lower cost scopes being used in 3 Gun matches today is the Simmons Pro Diamond run by Benny Hill from Texas. These are about $80. Actually more important that a scope is a good trigger for your AR. Most factory triggers are crap, too heavy and sloppy for good shooting. Prices range from about $120 to $300 plus. Here are a few, Jard, Chip McCormick, JP, Accuracy Speaks, RRA 2 stage, Timney, Jewel, and so on,

http://www.brownells.com/.aspx/cid=798/k=/t=S/mfg=/Products/AR-15-Triggers

I was thinking the trigger seems ALOT heavier than I remember on my old 30-06...