Mark III newbie sight in question

vikinghater · Post by **vikinghater** » Fri Apr 04, 2008 5:19 am

First of all thank you all (Especially Bullseye!) for this wonderful forum with such a nice atmosphere.

I am a proud new owner of a Mark III Hunter along with a Barska Electro Red Dot sight. The combo is very accurate!

I sighted the gun in at 15 yards at a indoor pistol range near my home (Appleton WI). From a steady rest it shot very accurate! I then moved to 25 yards and it shot about 1.5 inches high. At 7 yards 1.25 inches low. Obviously the bullet is traveling upward (I guess

). Question is how do you account for this in match shooting...which I do not participate btw. Just curious. Do I just aim higher or lower or do I remember the "clicks" to change higher or lower on the sight. I feel stupid asking this but I've never ran into this rifle shooting, although I probably did but the trajectry was so much flatter??

Paul

wlambert · Post by **wlambert** » Fri Apr 04, 2008 8:36 am

It is going to depend on what competition you shoot. I shoot Bullseye Pistol at 50 feet, 25 yards, and 50 yards. I zerro my .22 at 25 yards, and no adjustment is required. I am dead on at 50 feet and 50 yards.

If you are doing serious precision shooting, you are better off adjusting your sight rather than trying to adjust your hold.

On my .45, I need to adjust 4 clicks to go from 25 yards to 50 yards. I mark the two locations on the turret with finger nail polish.

wlamber

melchloboo · Post by **melchloboo** » Fri Apr 04, 2008 10:57 am

I do not shoot with a dot, but have heard similar comments from my bullseye club members. They zero at 25yd. for the day, and sometimes further adjustment is not required, or else they mark the dial based on previous experience.

I think to some extent it will depend on your scope. But also, Bullseye has commented here on how a bench test with a dot scope can be misleading because it may not actually be where you see the dot in your actual hold, and I have heard this from others too. Even during a bench test, you have no guarantee that you're looking at the same angle/distance when you move the target out between tests. I'm not saying this explains the different centers you're getting, just something to keep in mind as you zero in your scope...i.e. I think the general wisdom is to do it from your natural hold if you can find a way to support/steady the pistol while doing so.

Post by **Bullseye** » Fri Apr 04, 2008 5:28 pm

You ask a good question about the trajectory of a 22 LR bullet. Here's a chart to help with the ballistics.

Many may recall that I've said that the 22LR cartridge has a very flat trajectory. When looking at the chart, one can see that the difference between the impact of a bullet at 25 yards is only about 1/4 inch different than one at 50 yards. However the bullet isn't flying straight (horizontally), it's actually arcing upwards then downwards between those two distances. That is why most bullseye shooters don't make sight changes between the short and long line with a 22 cal pistol.

This isn't the same as the flight path of a larger caliber bullet like the .45 bullet. Most bullseye shooters make four to five clicks (Bo-Mar rear sight) changes between the 25 and 50 yard lines for the bigger bore pistols. Practice reveals how much correction each shooter might need to keep the impacts in the center. Some shooters change aiming points vice making mechanical sight corrections. For example; Holding at six o'clock for 25 yards and using a center hold for 50 yards.

Your optical scope mounts significantly higher than the bore axis, or the mechanical sights mounted on the receiver, so corrections between the yardages may be different. Again practice will reveal the amounts of sight correction changes between the these two sighting systems.

Hope this helps.

R,
Bullseye

45dave · Post by **45dave** » Fri Apr 04, 2008 10:57 pm

Hey, great looking chart. Last weekend I was working on figuring out where I was at different yardage, 25 (zero) 50, 75 and 100. What I found in the field was darn close...about 1/4 inch at 50, 3 inches at 75 and almost 6 inches at 100. Darn that chart would have saved me time.
This Sat I will be sighting in my new scope, looking forward to something with more magnification and a better cross hair set up.

vikinghater · Post by **vikinghater** » Sat Apr 05, 2008 1:13 am

Thanks to all that replied! Bullseye that chart is almost to the T what I experienced...whew! I thought I was doing something wrong, I really love this gun and can now just concentrate on shooting

Thanks again!

Paul

melchloboo · Post by **melchloboo** » Sun Apr 27, 2008 5:57 pm

I have a feeling I asked this before, but is there a similar chart somewhere for standard velocity (about 1000fps) rounds?

Post by **Bullseye** » Sun Apr 27, 2008 7:31 pm

Here's one for 1080fps.

R,
Bullseye

melchloboo · Post by **melchloboo** » Sun Apr 27, 2008 7:54 pm

thanks.

it is a little hard to say exactly from the chart, but if I understand it correctly, with both standard and high-velocity ammo, if a pistol is zeroed for 25 yards, then the same sight picture at 15 yards will give a point of impact roughly .5" below X?

I ask because most of my club's "fun" matches are 25yd/15yd events. I have not been adjusting my sights, but have noticed groupings are about an 1 or 1.5" lower. I have not yet decided if I should adjust the sights or change my 15yd. hold accordingly.

Post by **Bullseye** » Mon Apr 28, 2008 5:18 pm

If you have your pistol set at point of aim at 25 yards, then the bullet's impact at 15yds would be approx. 3/4"inch lower than the aiming line.

R,
Bullseye

melchloboo · Post by **melchloboo** » Mon Apr 28, 2008 5:45 pm

So I guess the next question is if a click adjustment on the stock ruger sights is in order. Are you aware of any chart that for a given distance, will tell how much the point of impact will move per click? Also, is a "click" standardized across sights and manufacturers, or will it vary? Lastly, does the answer to the first question depend on the distance from front to rear sight as well?

Of course, I am finding that much in bullseye shooting is trial and error, but its nice to know what should theoretically be happening...

Post by **Bullseye** » Mon Apr 28, 2008 10:15 pm

There are different amounts of correction and direction for each brand of sight. This chart may shed a little light on it for you.

R,
Bullseye

melchloboo · Post by **melchloboo** » Mon Apr 28, 2008 10:33 pm

Ah yes, I have that chart and forgot about it. Is it linear, in that at 15' one click will make 3/10" (.3) p.o.i. difference? Therefore, to compensate for a change in 25' to 15', which we said was 3/4" (.75) p.o.a. drop, two or three counter-clockwise clicks ought to zero, more or less?

Post by **Bullseye** » Mon Apr 28, 2008 10:41 pm

Yes it is linear. Your calculations should put you right on the mark at 15yds.

R,
Bullseye