AusVarmint

Being someone who is is a bit of a techno-phobe I purchased my first rangefinder this week. The leupold RX-II. Perfect for me i.e. very easy to use.

I really like the "True Ballistic Range" function, which takes into account shot gradient. Also the "1st" and "Last" target functions for ranging your target in areas crowded with objects.

All sounds great, but the proof will be in the field in about a week when it will be used to help take the heads off bunnies @ 200yds +.

Flyer

Hi Mate

I am using a Leica 1200 rangefinder, and I tell you you'll love a rangefinder in the field.

I am just finishing up my dropchart for my 308, and then I'll have no hesitation at having a ping at a fox at 500m.

I have modified my dropchart 3 times now.... and hopefully after my next lot of testing it will be pretty spot on. Ballistic software is very very close to what I am getting until about 320m, from there to 500 it gets a little different. What the ballistic software is telling me and what I am seeing in the field, its different by 1MOA. Thats 5 inches at 500m.

All sorted I hope. Using the Leupold varmint reticle, with only one scope adjustment, I have zero range at 100m, and can extend out to 500m.

Enjoy your rangefinder...

Cheers
AI

AI, a drop chart? Never heard of someone making one of these how do you go about it? Also can you use rangefinders spotlighting, never used one so im not sure how stupid that question is just yet

Mate

For spot lighting I think a dropchart or a rangefinder would not be much benefit to you.

If your using a 22-250 or something around that you can usually hold centre and hit the target anyway. The distance that the light shines is the reason behind this. If your shooting out to distance where you need a rangefinder/dropchart under the spot light I might question if you can safely identify what your shooting at.

Dropchart.

This is the way I made mine.

1. Found a accurate load
2. Zeroed at 100m.
3. Zeroed at 300m. Recorded how much MOA I needed from my 100m zero.
4. Zeroed at 400m. Recorded again the MOA from 100m
5. Same as above for 500m.
6.Took this information and adjusted ballistic software to match was I was getting out in the field.

I have a dropchart that gives me how much MOA I need from 100m to 500m in 10m increments, and its darn close!!!

You need a different dropchart for each different load you are using however.

If you need anymore info. just ask!

Herres a pict. of mine..... well the old one as I have changed it slighty since the photo.



Cheers
AI

AI, I am very impressed.

Thats good, and aspirational. Interesting method too


Which software did you use - I assume you adjusted the ballistic co-effecient till you got it to match the tracjectory. Does that mean you have also measured the muzzele velocity?

Spill your guts everyone wants to know now How did you find getting a zero for the rifle at those ranges? You were using a .308 right? Think it might be a waste of time with the little 224 projectiles at 500m what do you think would be a good max range for a .22-250. Firing 55gr at 3850fps......say 300m maybe???

The ballistic software is this one. I have found it to be really good.

http://www.eskimo.com/~jbm/ballistics/t ... basic.html

To get what I was seeing in the field I changed both the velocity and projectile BC. I do not have a chrony, so I was only guessing my velocity anyway. I would be surprised if I put the 308 over the chrony, just to see how close it was to what I am using in the ballistics software.

Well, I used this software to predict the drop. This is a good way of at least getting yourself on the paper at extended ranges. Fom there, you adjust to get the zero.

So, I zeroed my rifle at 100m. Then I looked at what the ballsitic software was telling me with how much MOA I needed to be spot on at 300m. I clicked the scope up to this, then I shot and it was close. I adjusted the scope so it was zeroed at the 300m, and then recorded.

Then again, I did the same at 400m and 500m, and recorded how much elevation I needed to get these zeros.

Back to the ballsitic software. I changed the velocity and BC until the software was matching (darn close) to what was actually shot.

Hope this helps..... good luck...

The Remington PSS has surprised me at 500m. Shot four 5 shot groups that were as follows. 1 at 6" with 2" vertical, 1 at 6" with 3" vertical, 1 at 3" round and 1 at 4" round. The day was fairly calm, only a breeze now and then, so it was easy shooting. Still got some horizontal drift though....

The 22-250 would be flatter than my 308 all the way out to 500m I'd say, just the retained engery and wind drift would be not as good at a guess!

Ask if you need more info.

Cheers
AI

What kind of scope are you using for this? I havent tried altering the scope during hunting to adjust for different targets but does it work when you alter it back and forth???

Im using a Leupold 8.5-25X50 LR with the vamint reticle. With this reticle, I only need to make one scope change which is only needed at a target after about 350m.

Then when I do, it is 29clicks of elevation and then that will cover me, using the varmint reticle, from 350 to 500m.

My scope goes back to where I originally had it when I return to the home position. For some reason, I'm not sure why, but I go one over or under then click back one. ie. For 29clicks, I'll go 30 then back one to 29.

A mildot reticle or another with added hold points makes using a dropchart a lot easier. With a standard cross hair, for every distance you'll have to change the elevation on the turrets. Before long, believe me, you'll lose where abouts you are with your clicks.

In the picture above with my dropchart, the centre piece of paper is a picture of my reticle, with the MOA recorded for each hold point.

Just try it once using the software. Pick a distance of 350m, move your elevation to it and have a go. You'll be surprised how close you get!

Cheers
AI