Nope. 1 click at 100 is 1/4moa. 1 click at 200 is 1/4moa. 1 click at 1000 is still 1/4moa.

Its just that the linear measurement of 1/4 moa changes with distance. It's still 1/4moa.

11 moa will always be 44 clicks on a scope with 1/4moa turrets.

Assuming your scope's dials adjust in 1/4 MOA clicks (as opposed to 1/2 MOA clicks or .1 mil clicks), every click is a 1/4 MOA regardless of distance. What you'll need to do is get away from inches and think clicks, but meanwhile...

1 click will move the bullet's impact 1/4 MOA and (roughly) 1/4" at 100 yards.
1 click will move the bullet's impact 1/4 MOA and 3/4" at 300 yards.
1 click will move the bullet's impact 1/4 MOA and 2" at 800 yards.

So... if you need to move the impact 2.25 MOA -- regardless of distance to the target -- you must make 9 clicks.

Use your scope's reticle to measure MOA at the target. If you have a first focal plane reticle, the reticle measurement will be accurate at any magnification. If you have a second focal plane reticle, the reticle measurement will be accurate at only one magnification level -- most likely the scope's maximum magnification.

In case you still want to work with inches at the target (if you're walking out to the target to measure elevation errors), you will have to convert from inches to MOA. In this case
1" is 1 MOA at 100 yards
2" is 1 MOA at 200 yards
4" is 1 MOA at 400 yards
1.5" is 1 MOA at 150 yards

For your last question, if you need 11 MOA (regardless of whether it's at 500 yards or 5,000,000 yards), you need 44 clicks (11 MOA times 4). I don't count clicks, as my scopes have good markings for full MOA values. For example, if I need 7.7 MOA, I rotate the dial to "7" without counting or feeling clicks, then feel for 3 more clicks to make it 7.75 MOA.

quote:

Originally posted by TKO:
So, for the MOA like 1.8... How do I do that? Closest I could get is 1.75 MOA, right?

Yes, go for the closest 1/4 MOA value. The vast majority of gun/ammo/shooter/weather conditions mean that .1 MOA impact results are a pipe dream.

In all honesty, if you can consistently achieve 1/2 MOA results on shorter distances, you're a frickin' hero. If you can consistently achieve 1/2 MOA results at long distances, you need to quit whatever job you're doing, become a professional shooter, and when you're not cleaning up in competitions, please teach the rest of us slobs how you do it.

Just watched a couple of videos and think I have it now. The scope has good markings for MOA so Ill quit counting clicks, set my zero stop where it is now and go from there.

All my life Ive thought in inches and used holdover at distances beyond my zero. This is definitely going to be a learning curve.

quote:

Just watched a couple of videos and think I have it now. The scope has good markings for MOA so Ill quit counting clicks, set my zero stop where it is now and go from there.

All my life Ive thought in inches and used holdover at distances beyond my zero. This is definitely going to be a learning curve.

Yes it is a learning curve but it comes quickly.

One of the neat things about this end of shooting is all the things you can learn. Physics, meteorology, math...take your pick. Whats equally frustrating is how easy it is for things to slip away too if not practiced regularly. Its all a great challenge. There is such a huge amount of new technology available too. Ballistic programs, Kestrels, bullets that prolly have more research put into them than the Apollo Project (OK...maybe not quite). Its also neat when you can ditch all that stuff, make some mental calculations, and connect with a plate hundreds of yards distant. In my case, its still prolly not more than blind luck, but its still cool!

I'm not keen on using 100yrds as my base, unlike fritz. I do agree that he makes a good case for that, but in my situation it just doesn't work for me for my F-TR match rifles because 1000 yards is where I work and I do not have enough adjustment to get to 100 yards.

But that's an extreme case.

For my hunting/battle rifles, I use another feature of JBM that is not very well known; PBR or Point Blank Range. Here, you decide the size of the vital zone, or rather, the radius, and JBM will calculate the maximum range at which you should zero your rifle with that load so that the bullet will fall in that specified vital zone from 0 to X maximum range.

This is especially useful if you are in a hurry.

So let's assume that the radius of the vital zone in the specs above is 3 inches. This means a vital zone of 6 inches in diameter. I think in a hunting situation having a zero that will land a bullet within a 6 inch diameter of wherever you put the crosshairs should be good.

So, with the specs above, JBM shows that if you zero the scope at 230 yards and you aim dead on target, your bullet will land within that 6 inch diameter vital zone all the way to 270 yards, without any holdovers needed.

For hunting/battle/steel situations this PBR is something to consider. For killing paper, where fractions of MOA come into play, not so much.

quote:

One of the neat things about this end of shooting is all the things you can learn. Physics, meteorology, math...take your pick. Whats equally frustrating is how easy it is for things to slip away too if not practiced regularly. Its all a great challenge. There is such a huge amount of new technology available too. Ballistic programs, Kestrels, bullets that prolly have more research put into them than the Apollo Project (OK...maybe not quite). Its also neat when you can ditch all that stuff, make some mental calculations, and connect with a plate hundreds of yards distant. In my case, its still prolly not more than blind luck, but its still cool!

You are not kidding! I have been playing around with this long range for a year and a half or so and I am still figuring out my applied ballistics app Learning wind has been very difficult since where I shoot the wind always seems to be pretty negligible. I must admit that every time I get a result I wasnt expecting I go back to the drawing board and work hard on improvements and normally I would find this maddening. Now, I cant wait to make more bullets and sneak off to the hour long drive to the range in the middle of nowhere Utah and test it out. Hell yesterday, I got the Applied ballistics book i had ordered right before work and i wanted to stay home and dive into it. Weird. I dont know if i should describe this part of my hobby as a passion or an obsession.

lets see if you guys can help me with my current issue. My reloading started with once fired military 308 brass. 208gr AMX pushed by RL17 powder(Only components I could find during the last shortage). Worked up my loads to about 2560 feet per second and was getting good accuracy. Temps were in the low 40's and low humidity at around 5100 feet above sea level. Made a couple of hundred of these roaunds and they flew pretty well.

Recently happened upon some new Lapua 308 brass and I gave it a try. Same formula as above but it was warmer outside around 55 degrees. Rounds were all low and chrono showed a drop of 210 fps in velocity difference from my earlier rounds? Only difference was the new lapua brass vs the military once fired and some tmep change. Any ideas? I can always doubt my chrony but the results seem to agree with the velocity displayed. My powder scales seem to be accurate when comapred to other weight results.

Military brass is thicker so you get higher pressure with the same charge weight.

If the lapua can handle it, up your charge. If not, still with the lake city.

That's a heck of a difference just with brass change alone. Reports I have seen show Winchester brass holding 2 more grains of water compared to LC brass. I believe that Lapua brass is heavier than Winchester so I'm not sure how much different it would be from LC.

At any rate, there are a few things to consider when using a chrono, especially on different days and these consideration have a great deal of impact on observations.

Using a chrono consistently is not easy, and a Chrony is more finicky than most people realize.

The first think you need to do is measure the distance from the muzzle to the first screen. This distance MUST be the same every time and guessing my eye is not good. When I used my Chrony, I had marks on the long cord to the display that I used to set the distance every time. Next you must make sure the Chrony is unfolded completely; I have seen many people use their Chrony not unfolded completely. The shorter distance between the screens will mess you up.

Next, the Chrony should be perfectly level and aimed perfectly straight so that the bullet travels the shortest distance between the screens every time. If your device is askew, your changing the velocity.

Finally, you need to aim through the device the same way every time and that gets difficult, especially from one day to another.

With so many moving parts and it is difficult, but not impossible to get reliable, repeatable readings. If you compare one load shot on one day with another load shot on another day, you have no clue what the difference if your chrono setup is not perfect every time.

This is why my Chrorny languishes in its box somewhere and I have a Magnetospeed V3.

Now for your load; I noticed that you do not tell us how much powder you are using and I assume the primers were the same. It would be useful to have that information.

Finally, as exx1976 indicated, different components can and will have effects on loads, which is why "serious" LR (or any) competitors will standardize on various components and buy in bulk from the same lot then refine their load with that batch. Lapua .308 brass is about as good as it gets for brass. LC Match brass is also excellent but once-fired military brass is another kettle of fish; you have nu clue what it was fired in and chances are high that it was in some type of automatic firearm. To avoid uncontrollable variations in your ammo, I would suggest you buy a few hundred cases of virgin brass from Lapua, Winchester or LC and treat it all the same from the start.

Yesterday was a dry, hot, and windy for shooting rifles -- record heat for the day (mid 70's) and switching wind directions. And a dew point of -15 F. Yep, it was dry.

Figured out the prone location for an 804 yard shot to my big 18" piece of steel. This extends my maximum practice distance from 680 yards -- woohoo. Took quite a bit of weed whacking to get the prairie grass & weeds low enough to see the target. "See" in relative terms, as by noon the mirage from the warm ground was a bit interesting. Anyway, four shots with FGMM 175, four hits, about 12" lateral dispersion and 3-4" vertical dispersion.

But a bad day for weed whacker juju. I stepped on the damn thing in the garage this morning, as I didn't put the stupid tool back where it belongs. So, off to the doctor today morning for tetanus booster. Yep, I'm a sheep dip.

quote:

Finally, as exx1976 indicated, different components can and will have effects on loads, which is why "serious" LR (or any) competitors will standardize on various components and buy in bulk from the same lot then refine their load with that batch. Lapua .308 brass is about as good as it gets for brass. LC Match brass is also excellent but once-fired military brass is another kettle of fish; you have nu clue what it was fired in and chances are high that it was in some type of automatic firearm. To avoid uncontrollable variations in your ammo, I would suggest you buy a few hundred cases of virgin brass from Lapua, Winchester or LC and treat it all the same from the start.

Thanks Ex, I had thought that about military brass but wasn't sure about its effect.

Thanks Nikon, Good points on the chrony. You are correct i have been eyeballing it. I have been stocking up on Lapua brass where and when I can find it. The primers are all the same cci large rifle. The powder load of Rl17 is 44.6 grains. I pushed it to 44.8 grains but began seeing sticky bolt. Magneto speed is next on the list as I am very tired of the chrony and its obvious errors. It constantly has errors on reading 223 frequently showing speeds for 223 in the 9300 fps realm.

I am still trying to figure out the kestrel and wind. I have been logging the station pressures in applied ballistics app and they are always about the same 24.98-25.12(5100 asl) and it seems easier to use the station pressure rather than accounting for altitude and pressure. All of my previous data with this load showed a slight increase in velocity with a temp increase with temps taken in the 40's to the 60's. I dont think the environment and higher temps could be partially responsible for my 200 fps swing as my data shows temp increases velocity. Could pressure, humidity have any effect on velocity?

I have data on 308 case capacity if anyone wants it. Includes Lapua, BHM, LC NATO, and other less useful headstamps. Small Excel spreadsheet.

I would post it here, but the formatting just doesn't work out.

Email in my profile.

RMD

<EDIT> Found this in a photo file. Grains of water. (N) is a NATO case.

This message has been edited. Last edited by: rduckwor,

quote:

Originally posted by gw3971:

quote:

Finally, as exx1976 indicated, different components can and will have effects on loads, which is why "serious" LR (or any) competitors will standardize on various components and buy in bulk from the same lot then refine their load with that batch. Lapua .308 brass is about as good as it gets for brass. LC Match brass is also excellent but once-fired military brass is another kettle of fish; you have nu clue what it was fired in and chances are high that it was in some type of automatic firearm. To avoid uncontrollable variations in your ammo, I would suggest you buy a few hundred cases of virgin brass from Lapua, Winchester or LC and treat it all the same from the start.

Thanks Ex, I had thought that about military brass but wasn't sure about its effect.

Thanks Nikon, Good points on the chrony. You are correct i have been eyeballing it. I have been stocking up on Lapua brass where and when I can find it. The primers are all the same cci large rifle. The powder load of Rl17 is 44.6 grains. I pushed it to 44.8 grains but began seeing sticky bolt. Magneto speed is next on the list as I am very tired of the chrony and its obvious errors. It constantly has errors on reading 223 frequently showing speeds for 223 in the 9300 fps realm.

RL17 is not a temperature insensitive powder like Varget. As the ammo gets warmer, so does the load and the converse is true also. It's a great powder with lots of applications but competitors shy away from it because of that temperature sensitivity. As for the Chrony, it's a finicky machine and you have to baby it.

quote:

I am still trying to figure out the kestrel and wind. I have been logging the station pressures in applied ballistics app and they are always about the same 24.98-25.12(5100 asl) and it seems easier to use the station pressure rather than accounting for altitude and pressure. All of my previous data with this load showed a slight increase in velocity with a temp increase with temps taken in the 40's to the 60's. I dont think the environment and higher temps could be partially responsible for my 200 fps swing as my data shows temp increases velocity. Could pressure, humidity have any effect on velocity?

Pressure, heat, humidity and so on all have effects on velocity. You mentioned that the impact at distance was changed, but you didn't explain how much and in which direction, you did indicate that it seemed slower. I'm sure changing the brass has an effect, I just don't think it's has much as 200+ fps. With more info we can try to figure out more.

Since it still too damn cold to shoot here I figured it was a good time to set up a new target. Almost finished, just need to clean up as couple details. Now if the weather would just cooperate

quote:

Originally posted by jlemmy:
Almost finished, just need to clean up as couple details.

Looking good.

Uncertain if this is your first target setup....
FYI, expect shrapnel from the target splashes to embed in your wood support posts. The lead will generally be a soft-ish gray covering, but the copper can be sharp little shards sticking out from the wood. Wear leather gloves, keep the gloves away from children (lead contamination), and wash your hands before eating/drinking/smoking.

Fritz,

Thanks for taking the time to give some feedback. My other steel target is a pepper popper on a steel base. It's rigged so it doesn't fall when hit. I gets lead splatter all over it but of course doesn't embed. I always wear gloves when handling that one to cut exposure.

With this target I was looking for something a little more reactive when hit. It still needed to be portable as it needs to be set up on every range visit. We shall see how the wood holds up but I wasn't sure what else I could have used and stayed light. If it's muddy I need to carry it the 600 yards to set it up. Did I mention that I hate when its muddy. Any other suggestions would be appreciated !

what is the size of that wood? The belt looks to be 4" wide, which would make the wood and inch, inch and an half? My club uses 1.5x1.5 and they rarely last 6 months. Once stray 30 caliber bullet into the cross beam and it could spell game over

Your targets will definitely move, given the long strap and a single hanging point. I'm guessing those are either 6 & 8 inch or 8 & 10 inch targets. My longest targets on straps are 12" at 580 and 636 yards. Target movement with both .308 and 6.5 Creemoor are quite noticeable, with .223 it's more subtle. Your smaller gongs will really swing at 200-300 yards, possibly enough to do the loop-de-loop, wrapping around your top horizontal bar. Last fall I did that in a T3 Ranch match, and the target ended up resting on the top of the bar -- I had to shoot it off in order for the next guy to have a hanging target.

Your support system will rock more with hits on the smaller targets than on the large one. At 200-300 yards, you might find that the front or rear of the base may rock off the ground briefly.

You will eventually misjudge wind badly enough that you put a bullet through your support posts. Realize that you will eventually have to replace the wood supports, so glue/screw/clamp accordingly. So far I've hit two of my support posts (fixed position steel T-posts, the type for barbed wire fence). Fortunately the two hits just winged the posts, instead of hitting the center of the "T".

I find that Rustoleum white spray paint works well for repainting targets. IMO Krylon is a little thin and runny, especially if you place an orange aiming dot in the center of the gong.

I made some shephard hook thingies for mine. It allows me to hang from the strap or use 2 and put a piece of rebar across them and secure to the hooks with strap clamps. I need to either make a few more or come up with another idea in the next few days. Im taking a road trip to ND and hoping to get some shooting in. My hooks are presently still frozen into the ground...

jlemmy: those plates from Arntzen?