BigGameHunt.net Hunting Forums

[Don Fischer]

Once I get to where I'll have to re-adjust the sights, how do you firuge it. My print out shows with a 230yd zero that at 500yds I'm 36.5" low. I think that's a bit over 5 MOA. There must be some number to devide into 36.5 that tells me how many clicks to move the sight's? Divideing by 5 only gives me 7.3 clicks. That can't be right is it? Or is it 7.3" at 100yds which would be 7.3 x 4 = 29 clicks?

[hostage67]

The clicks are based off of a 100yd range. I'm not sure what the sights are set at exactly but it would seem that most scopes use a 1/4" per click measurement at 100yds.

If you are shooting below 100yds you would need to multiply the number of clicks depending on how far you are shooting. If you are shooting further out then you would be dividing the number of clicks based on your range.

So if you are figuring you're off by 5" MOA then assuming your sights use a 1/4" measurement then you would be looking 20 clicks not 7.3.

MOA is a measurment based on 100yds so if you determine that it's a 5" MOA varience then you would be making the adjustment as though you were trying to move your aim 5" at 100yds.

That being said your sights may not be set to 1/4" adjustments so finding that out would be the first step :).

[Don Fischer]

Let me put this a different way. I'm sighted in 2" high at 100yds and I'm 36.5" low at 500yds. How many clicks up do I have to move the elevation to bring the zero up to 500yds? How do you figure it? The scope does have 1/4 minute clicks.

[ChesterGolf]

It really doesn't matter where you sight it in Don. The fact is you are 36.5" low at 500 yds and if each click is 1/4"@100, it is 1 1/4"@500yds.(1/4x5=5/4") So going with that info you need to figure out 36.5/1.25 to figure out clicks.

36.5/1.25=29.2 clicks so 29 clicks will make you 1/4" low and 30 clicks will make you 1" too high. Hope this all makes sense.

[fuzzybear]

Just a bit to add. If your scope is zeroed at 100 yds. 500 yds is an additional 400 yds not 500 yds.Be sure that you have the scope set so you can adjust it to extreme ranges.

[Don Fischer]

OK. Think I got it. Going out today to fool with the new scope. That should come out to each click being 1" at 400yds (1/4 x 4 = 1). That right? At the extream range for sporting rifle matches, 700 yds, each click would then be 1.75", right?

Thanks you guy's.

[Don Fischer]

Fuzzybear,

I counted my windage clicks and gave up at 200. I'm guessing that I have the same number of elevation clicks. Think I'll go count befor I zero this thing! :thumbsup1:

[ChesterGolf]

Sorry to disagree fuzzy but it doesn't matter where your scope is zeroed at. No matter where the scope is zeroed Don has to bring the POI up 36.5" and the target is still 500yds away. The bullet takes the same arch. Don knows from shooting the rifle that he is 36.5" low and he has to compensate for it.

[fuzzybear]

I think we're on the same page. Just adding a few insights.
Don, You won't be able to tell what the exact adjustment is until you shoot the load. On paper it may say 36.5" low but, until you know what the rifle is doing. It's all speculation.

[Don Fischer]

Of that I'm sure. When I set up even a hunting rifle I shoot at paper from a bench at ranges to 400yds in 50 yd incriments just for that reason. This new game of sporting rifle match calls for much more knowledge than I have now. Had no idea how to figure what one click equaled at 500yds.

Also getting a whole new perspective on long range shooting that enforces my beliefs about long range hunting. Shooting at an inatimate target it is a game, nothing more. The mechanics of it are demanding in that you must learn the disapline to make shot's on purpose. For instence, it now appears to me that the heavy bullet must be determined by the twist rate of the rifle used. Perhaps that is why the military is using 173gr bullet's in their sniper rifles, they are optium for the twist of the rifles being used? Zak mentioned keeping the bullet above supersonic speed. To fall below let's the bullet become unstable and good shooting becomes a matter of shoot and holler do-do. Brings to mind my old 308 Rem 660 that my son has. It never shot anything as well as 165gr bullet's but shot 180gr bullets acceptably well. It was the twist rate wasn't it? thats where the militaty got the 173gr bullet from?

For me, this long range thred is a real education thanks to individuals like Zak Smith and C.G. who are willing to share knowledge well beyond where most of us are at.

Well off to the range and fool with this rifle. By the way, this will be a target rifle only now. Might get the chance to go to New Mexico after I retire. Will stop and drag cowgirl and her spousal unit along. Ya got at least a year girl!

[Don Fischer]

C.G,

It seems to work great. Only had 9 rds loaded up so fired one at 50yds after bore sighting. Then re-aimed and moved the cross wires to the bullet hole. Moved the target to 100yds and fired one more then adjusted to 2" high at 100yd. Moved the target to 405 paces, fairly close to 400yds. Had a printout with this load and it showed -18.3 @ 400. Moved the crosswires 18 clicks and the first shot hit just under 3/4" high and 3" right @ 400. Fired two more and got a group 3" c to c with 2 shots in 3/4". Moved the crosswires 3 clicks left and fired last two rounds into 1 3/4" w/ center of impact 1 1/2 left and 1 1/4 high. The aiming point in the photo's is 6 3/4". Sighted in and shot at 12 power.

Here's what a target looks like at 400 yds. Target is to the left of the rifle, a white spot in the field down range just in front of the small dark spot. I can see where this "sporting rifle match" could be a hoot!



Here's the target.



I was thinking I'll probally try the 129gr SST bullet. A bit better BC and the protected point may help some plus the A-Max profile. Not sure I can get this accuracy with 140gr match bullet's or the 123 gr match as I'm not sure a 1-9 twist will stabilize them quite well enough?

Forgot to mention. This stuff could make you a very skinny guy. I walked down range after each shot to mark them! I am getting a 4 wheeler!!!!!!!!!!

[Zak Smith]

Most good ballistics programs will produce data accurate within one "click" if you give them the right inputs. I talk about it here:
http://demigod.org/articles/pr.....equipment/
(towards the bottom)


If you have a zero and know the drop data in inches at subsequent distances, to get scope adjustments for those distances

Drop in MOA at distance X yards = drop in inches / (1.0472 * X/100)

For 36.5" drop at 500 yards from a 230-yard zero, that's
36.5 / (1.0472*5) = 6.9 MOA drop

[cowgal]

Don Fischer wrote: O Might get the chance to go to New Mexico after I retire. Will stop and drag cowgirl and her spousal unit along. Ya got at least a year girl!

Ha ha! I think I'll start calling my husband the "spousal unit" - I like that! :lol:

I'm game, guess I better get in gear and start practicing.

These new threads have been great, lots of really good info. Thanks guys!

[fuzzybear]

When I was frequenting the range more often than I do at the present. There was a gentleman that would spend hour upon hour shooting the 500 yd target with his LR rifles. He always had his pickup and a box trailer with a complete reloading bench w/accessories and usually three rifles. He had more gear in that trailer than most of us have ever heard of. He would set up at the shooting bench. Fire one round and go back to the trailer to make adjustments.
On one occasion I asked what he was doing. He replied that he was trying to find the load that would give him exactly 3000 fps out of his 6.5/284 (the rifle he was currently shooting) and maintain the accuracy. 3000 fps was optimal for that round. Out of that rifle. With that bullet at 1000 yds. It maintained the speed necessary for stability for the entire flight of the bullet.
That is some downright devotion to the sport. It was quite a routine. I saw him just about every time I was at the range and always working on his loads.

Don
Is that the 6.5-06? I would guess that the 6.5/284 and the 6.5-06 are about the same capacity. Was the bench steady enough to determine how accurate the rifle is.
The range I shoot at, to determine accuracy, has covered concrete benches. The same ones they use for the events. It rains quite a bit and usually at the least convenient time.

Those charts, attached to the rifle, that Zak was talking about are a great way to keep info handy. I made one chart but not quite so handy.

[Don Fischer]

fuzzybear,

Yes the 6.5-06 and 6.5-284 are so much alike in capacity so there's no practical difference. I like the 06 version because I know I'll always be able to get cases. If I do it again, It'll be a 6.5-270. Then I can do all my cases on 270 cases without all the trimming to make them fit.

The bench is more than steady enough. The only drawback is the third leg takes some getting used to. Been shooting off it a long time tho so I am used to it. The way it is is nice because it's fairly light and with the trird leg that way, your weight get's added to the bench. Braces on the front keep it stable sideways. Table is a bit small tho and I'm to lazy to build a new one right now.
Wish I had a bit more room to set the cronograph up on, it works but takes up to much room.

Here's a group shot while I was doing load developement. I have many like this from several different rifles. Three shot's at 100yds.