Help! Need advice from experienced long range shooters.

[YOURSUPREMECOMMANDER]

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[2506]

Just curious if you've found ambient temp/cartridge temp the same across all powders? I've never taken the time to drill that far down into it, but I believe some powders are touted as less temperature sensitive than others--I'd like someone with empirical evidence to weigh in.

 

[salmonriverjohn]

I too would be interested in variations found. Perhaps member USMC would like to chime in here?
He's an excellent resource and the dirt bag that really messed with my brain when he started factoring in Horizontal and vertical Coriolis drift and spin drift into the equations of +1k yard shots that had to be doped. The science behind it is actually pretty cool.

 

[YOURSUPREMECOMMANDER]

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[YOURSUPREMECOMMANDER]

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[YOURSUPREMECOMMANDER]

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[YOURSUPREMECOMMANDER]

Yes I can hear the hits! Nice shooting, especially in the wind conditions your up against and a ten inch gong, well done.
from the descriptions of the doping your using you seem like you pretty much have it together. Nice job. As 'just shoot' states, sticking may be an issue. And as Lang 22250 and orygun state (trust oryguns advice, he's an old sage) + he loves the -06,, got just to trust anyone that loves the -06, if everything's good at 100, you know your good to go. The rise due to thermal lift is often overlooked when distance shots are taken. It will cause hair (22250) to be pulled out at a later date after you know damn good and well you just had her doped at a certain distance but didn't factor in thermals. As a side note, that sure looks just like the terrain that I live in where your video was shot. Coast range.
Please keep us posted as to the results you come up with, Thanks.
God I love to shoot!

"God I love to shoot!"

I keep thinking about your final statement. I can really identify with it! I appreciate the honesty.
It's my understanding that we all need to "Get out of our heads", once and a while, and be in "The Zone". When I'm shooting, I'm at peace, and everything in the world is right! Because every bit of energy is focused on something I love!

 

[geometro]

Enter the BC and MV over at JBM with two different temperature, altitude, humidity variables and see how much, or how little elevation changes... 40 degF difference is going to be noticable over a long distance.

 

[AMProducts]

So I got some range time at one of the local ranges that has gongs out to 600 yards... I took one of my newer rifles out (mossberg MVP in .223) along with my .308. The .308 with the same load I've been making forever simply required dialing in the turrets for the conditions, and it was pretty much point and click from there on out. Even to the point that I was embarrassing the guy with the .338 lapua next to me as we were shooting at the same set of dingers, and I would hit them 9/10 times, and he was at about 3/10 times at 600 yards. This is why writing down the conditions and the hold-overs for each session matters. Frankly, I think practical data (that is, you sat down and shot the condition) is much more important than what a calculator can give you.

So then I pulled out the .223, by comparison shooting M193 ball at 4-500 yards starts to become a challenge again. Nice thing about the .223 is it shoots pretty flat with a 25 yard zero, you're still in point blank on most of those targets out to 300 yards, past that you need to start holding high. At 600, I was holding to the bottom of the reticle. I think I need to put a better scope on my .223, not sure what yet. Anyways, I now have a few hundred pieces of fire-formed brass, and a whole bunch of sierra 69gr BTHP I need to load up. Going to try those next.

 

[Ryo]

For some reason I was thinking just now about your question. And although I already wrote a lengthy response, I have some additional empirical information that might be of interest to you.
While there are variations in MV caused by cartridge temperature - this is of relative little concern compared to the difference in air density that different temperatures bring, when long distance shooting.
I remember a couple of winters ago I had a gong set up at 500 yards. The temperature was usually in the low 40's. I used 9.5 to 10 inches of elevation off my 100 yard zero, an would bang the gong all day long. I remembered taking a picture of my turret setting, and will post it below.
I went back to the same place the following summer when it was in the high 80's. I fired off a dozen shots and did not hit the gong. I know I'm not that bad of a shot, so I put on my thinking cap. I decided the air was going to be less dense and therefore would require less elevation adjustment of my turret. I slowly walked my elevation turret numbers down one click (1/4 MOA) at a time and took a shot. When I got down to 7.5 minutes, I hit the gong, and continued to do so using 6.75 to 7.5 minutes. I will also post a link of me at that very location shooting the gong in question at 500 yards in the summer.

Imagine my discovery. Over 10 inches change in point of impact just because the temperature was about 40 degrees different. It's hard to believe until you experience it.
I am aware that you probably already know of such things. Still, It really amazes me. Empirical evidence as such.
View attachment 82354

Air density does change quickly depending where you are. When I was in OR for training, I was easily banging 700 yards.. Guy who doing okay in class couldn't figure out why he was missing his targets. I told him the current density altitude and he was banging metal again. He didn't double check between morning and afternoon which had a large shift enough to make him miss. Long range shooting definitely can be challenging but that's fun.

Reading wind is my issue.. Sure I can read my local area but midway is where I need practice by watching the environment.

 

[YOURSUPREMECOMMANDER]

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[YOURSUPREMECOMMANDER]

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[PDXGS]

If you're shooting long range in terrain with slopes, it pays to spend a few minutes on the spotting scope or in the rifle scope just observing wind sign between you and your target. Upslope or downslope winds can have real effects on external ballistics. Understanding convection and pressure trend, and their effects on air movement, as the sun comes up or goes down, is critical to accurate shooting.

 

[YOURSUPREMECOMMANDER]

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[PDXGS]

As part of my job, I study low speed aerodynamics. I also shoot competitively and run SAR dogs in the Pacific Northwest. They all have a need to understand wind direction and what affects it in common.
When you figure it out, let me know!
Short of a Doppler radar system there's not a lot you can do but go for a .260 Rem or 6.5 mm barrel burner to compensate!

 

[YOURSUPREMECOMMANDER]

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[PDXGS]

6.5/.264(rem .260) is a whole lot less susceptible to wind than the .30 cal rounds...arrows compared to cabbages!
Most competitors are shooting 6mm or 6.5s in a variety of flavors- it's
Really hard to beat the ballistics and less recoil. I've never seen any advantage to going up in caliber for competition. You may get some extra energy onto the target but you feel like you've been kicked in the head and shoulder at the end of a 150+ round-day.
As a comparison, I once shot.30 cal, 175gr match kings competitively. At 800+ yards I would have to dial in 1-2 mils of windage to keep on target in a 10 mph full value right or left cross wind...with my .260, shooting 142 gr SMKs I'm holding the edge of target into the wind.
It's pretty insane.

 

[jluck]

6.5/.264(rem .260) is a whole lot less susceptible to wind than the .30 cal rounds...arrows compared to cabbages!
Most competitors are shooting 6mm or 6.5s in a variety of flavors- it's
Really hard to beat the ballistics and less recoil. I've never seen any advantage to going up in caliber for competition. You may get some extra energy onto the target but you feel like you've been kicked in the head and shoulder at the end of a 150+ round-day.
As a comparison, I once shot.30 cal, 175gr match kings competitively. At 800+ yards I would have to dial in 1-2 mils of windage to keep on target in a 10 mph full value right or left cross wind...with my .260, shooting 142 gr SMKs I'm holding the edge of target into the wind.
It's pretty insane.

Finally someone puts this simply. Gee... Your 'a saying there's a reason the 6-6.5mm is so dominant in long range competition?...

There seems to be a bunch of internet lore about the 6-6.5mm having drift issues and people lap it up while the people competing are not switching to a .30, Again totally weeirrd...

Caution
<Reply may contain sarcasm>

 

[PDXGS]

Yeah, crap what am I saying?! 6-6.5 totally suck for long range competition!
Everyone should go back to the 168gr SMKs in .30 cal and mil-dot reticles.....


Thanks for catching that!
Tongue in cheek....PDXGS

 

[YOURSUPREMECOMMANDER]

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