Need an answer? was it bulls*** or true?

Matt_3479

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Oct 12, 2009
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I was on the range the other day and speaking to a gentlemen and he was saying that anything that happens at 25 yards as far as group size is almost identical to what will happen at 100 yards as long as the shooter can do his part. Now i called bulls*** on that. He was saying anytime he freshly mounts a scope he shoots first at 25 yards (to make sure hes on paper and to test group size) to see if its even worth it to back it up to 100 then to 300 and so on? Now the other day i went to the range and with a gun i had remounted a scope on and worked up my first couple loads for it. I was at the 25 yard mark just checking zero before i moved back to the 100 (couldnt go to the 300+ cause range was closed for the day). figured why not touch of a couple shots with differen't powder charges. First shot at 25 was almost an 1 full inch. when i stretch to the 100 it was basically an even inch. the second powder charge was almost an even 1 hole group, and when i backed it out to 100 i measured the group being .386". then with the 3 powder charge stayed just high of half inch at 25 but opened up to about .75 at 100. now that couple have been me but it was basically what he said. Is this true, or just the way it happened to turn out?
 
So what are you wanting to know?

Will a good group at 25 yds equal a good group at 600 yds? Depends on the gun and ammo, nothing proves accuracy at distance, except distance. There are plenty of master snipers in Call of Duty world who cannot hit the toilet when peeing to prove me right.


The only thing 25 yds has ever told me is that the scope and rifle are generally lined up and heading the same way. One shot at 25 yds, saves time at the rifle line when dialing in a new set-up.
 
You know this is kind of interesting. I'm not saying I believe this or not but sometimes I start in my back yard before heading up the hill. I can get exactly 50 meters out of my yard if my feet are against my house on my back porch and a target is as far as I can see it through some trees as the hill starts. I have commonly shot groups that scared my at 50 meters of .5 or .75 MOA thinking that once I got up the mountain to zero my new gun it would be 1-1.5 MOA. My rifles has in many circumstances stayed somilar in size at 100 meters and subsequently had the same MOA value in size when I do a final Zero commonly at 200 meters. This kind of goes with what the OP is saying he experienced.

Like I said, not confirming that I believe that this is the case but is interesting to see that others have experienced this.
 
It really actually depends on caliber...

For lower calibers like the 308 and down, there's not that much climb once the bullet leaves the barrel so, you can get away with zeroing at @ 50 yards...

Will it be dead nuts on? No...Pretty damn close? Yeah.

Once you get into the larger calibers...No way.
 
You can use a ballistics calculator to test some of this regarding zero. For instance on the Berger Calculator for 6.5cm 130 berger @ 2800 ftsec with a zero of 100yds. At 50 yards the bullet is calculated to be 0.08 low. So theoretically a 50 yard zero would work for 100... For a 200 yard zero, it's 0.06 low at 25 yards...

With regards as to the precision of the load, you have to test at longer distances to determine if the load is going to work. There are lots of threads on the intricacies of load development!!
 
What is it that you are trying to say here? In no caliber will a bullet climb above the bore axis once it leaves the barrel.

Your line of site is not congruent with bullet trajectory...There's a greater arc involved when shooting longer distances...

I should have worded that differently...By climb I meant angle...

Not my day.
 
If you think of bullet trajectory as a parabolic path and your sight line below the zenith of said path then the bullet crosses your sight line twice. As stated above, with that particular caliber first at fifty yards, then at one hundred yards. So you can sight in at that shorter distance and be sighted in at a corresponding longer distance based on actual bullet trajectory. Will it be the same group at the longer distance? Probably not. Any deviation will be magnified by distance, in the same way that an moa shooting gun will be just that but at a longer range the group is bigger.
 
So what are you wanting to know?

Will a good group at 25 yds equal a good group at 600 yds? Depends on the gun and ammo, nothing proves accuracy at distance, except distance. There are plenty of master snipers in Call of Duty world who cannot hit the toilet when peeing to prove me right.


The only thing 25 yds has ever told me is that the scope and rifle are generally lined up and heading the same way. One shot at 25 yds, saves time at the rifle line when dialing in a new set-up.

This.

Just makes sure you arent burning up ammo trying to get on paper at 100 yards.
 
Trying to recall from hazy memory. But isn't this point blank range for hunters? Something like .308 round at 100 yards. They set .8 inches over point of aim. This means (can't remember exactly so don't take these numbers to heart) anywhere between 50 yards and 180 yards they can aim straight at the center of the heart and will be no more than an inch or two off up or down. Which would be a hit.

Below I'm just trying to simplify.

In terms of grouping. 25 yards is not going to be very good because it takes time for bullets to stabilize. It won't be identical. Just similar. Some people find this method easier to zero. Starting close then jumping to 100yrds.

In simple terms. As someone was mentioning.. You need to remember that your line of sight crosses the bullet's path twice in all but one instance (look up the word tangent).

Also, in simpler terms.. bullet never travels above the bore's line. The moment the bullet leaves the barrel it's falling.

First book I read before I bought my rifle.. Understanding Firearm Ballistics by Robert A. Rinker.



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