Testing different bullet weights for accuracy.

[Vodoun daVinci]

Long story short, I zero'd at 100 yards - my base fodder has been Hornady 6.5 CM 140 gr. ELD Match and I have been shooting solid and consistent .7 MOA out to 600 yards. So, I decided I'd start to experiment with different bullet weights and purchased a few boxes each of Hornady 140 gr. ELD Match, 120 gr. and 147 gr. and set up at 100 yards to shoot the tightest groups I could and see if there was a clear winner. There was not a clear winner. They all shot almost exactly to the same place (actually, exactly to the same place) and after 15 rounds of each weight (5 shot groups on 3 targets) I'm averaging .6 MOA. The absolute smallest group I shot was 5 rounds of the 147 gr. into 3 holes for a .45 MOA group...smallest group of the day.

I'm gonna try this again in a few weeks but if all things are this equal, does it make sense for me to pick the 147 gr. as my standard as I start buying other factory brands for comparison? All of the Hornady ELD Match shot virtually the same...so I'd pick the one with the highest BC and dial that round in exactly and move along.

Or am I not seeing this right?

Thanks in Advance.

VooDoo

 

[acourvil]

If accuracy is the same on everything, then compare the ballistics for the distances you are shooting. High BC is good, but velocity also makes a difference. Personally, I would chose the combination that gives the smallest wind drift at the longest distance you plan to shoot. That might be the bullet with the highest BC, but a faster bullet with a lower BC might have a better result.

 

[Vodoun daVinci]

Well...realistically I'd like to push the distances out past 1000 yards. Not every time but the goal is to hit steel at 1000 yards. Should I do the next test at say 600?

VooDoo

 

[acourvil]

Well, it’s definitely good to have real dope at longer range to verify the ballistics. But you can plug the velocities for each of the loads, along its the rifle details and the bullets into a good Ballistics calculator and see what the results should be. Those are common bullets, so BCs should not be a mystery. Use a 10 mph wind and see what the results are at 1000. For most people, I think the biggest challenge in long range shooting is the wind, so if one of the combinations has a wind advantage, I would use that.

 

[Vodoun daVinci]

I noticed today that with all the numbers plugged into Strelok it was off by 25%....calculated bullet drop to 200 and 300 yards incorrectly by 25% error.

So I'm going to have to settle on a round and create my own DOPE based on my rifle and conditions. lots of food for thought here. Super thanks !

VooDoo

 

[acourvil]

I haven’t used Strelok,but that sounds like some kind of data entry error. Maybe check all your inputs or try another ballistics program.

 

[b6graham]

ballisticsarc was very good for my with factory hornady

 

[Sniper266]

I do most of my load development at 200 yards. This helps to open the groups up in inches, and you can better measure the moa that youre shooting.

As far as bullet weight and accuracy goes, hevier bullets with higher BCs are less effected by wind. Lighter bullets fly faster and can reach the close range targets with more accuracy. For this reason a lot of high power shooters will change ammunition durring a match at differnt yard lines.

I would evaluate what you are trying to accomplish with your shooting. 120’s will likely give you better groups at 100 yards while 147s will group better at 1000 yards.

The right round for a certain job is important. I personally stick with heavier rounds as i am happy to carry a .7 moa group from 100 yards that will only grow a little bit at 800 vs a tighter group at 100 that will grow more over further ranges.

 

[b6graham]

what did i just read

high power shooters change for recoil. not because a 80gr groups better than a 108 at 200y. that's nonsense

the whole BC and wind thing is very speed dependent.

if you can wind call a .5moa 120gr will group the same as a 147 at 100y and 100y. you might just have less wind hold with the 147

 

[Vodoun daVinci]

You don't find that some rifles are inherently more accurate with different bullet weights? Is this common? I was under the impression that some barrels like some bullets and not others so much.

VooDoo

 

[b6graham]

You don't find that some rifles are inherently more accurate with different bullet weights? Is this common? I was under the impression that some barrels like some bullets and not others so much.

VooDoo

yes, no, maybe.

could be the velocity of that particular factory round too. that's why we handload

 

[PinesAndProjectiles]

I noticed today that with all the numbers plugged into Strelok it was off by 25%....calculated bullet drop to 200 and 300 yards incorrectly by 25% error.

So I'm going to have to settle on a round and create my own DOPE based on my rifle and conditions. lots of food for thought here. Super thanks !

VooDoo

Was what you entered for velocity actual measured velocity or what was printed on the box?

 

[Vodoun daVinci]

Printed on the box. That must be it. My DOPE is not matching the numbers I get from Strelok or Hornady ballistic apps so there's something wrong somewhere. I double/triple/quadruple checked all information and variables. No biggie. I am gonna push my next testing out further to 300 yards and see if all three bullet weights shoot the same sized groups.

If they are all roughly equal I'll likely settle on the 147's as my standard as they will buck wind the best and that seems to give me the most challenge.

VooDoo

 

[PinesAndProjectiles]

Yup, your numbers aren't adding up in Strelok. Just remember, the ballistics solver is only as good as the info that you put into it. Good numbers in, good numbers out. Crap numbers in, crap numbers out. I would invest in a Chrony also.

 

[luv2hunt6]

I noticed today that with all the numbers plugged into Strelok it was off by 25%....calculated bullet drop to 200 and 300 yards incorrectly by 25% error.

So I'm going to have to settle on a round and create my own DOPE based on my rifle and conditions. lots of food for thought here. Super thanks !

VooDoo

You probably already know how to and why but, in Strelok you have the option to use "Trajectory Calibration" and correct the elevation errors that you're getting. It's pretty much the same as with Gseven and a couple of the others that I've used. Once calibrated, it's a handy app that is pretty accurate.