Reply With QuoteIf I can hit that well with mine when I get it done you'll be able to hear me giggle, yes, giggle from where you are.
Did a quick 5 shot group today at about 1100-1150 ish yards. Light drizzle/misty rain but wind was basically dead. Occassional slight breeze up by the target.
Gun is my savage 11 based 300 wsm. 24" brux bull. Off the bipod with a weaver tactical 5-15x50mm mil/mil
Shooting 185 gr bergers juggernauts
First real attempt to group. I've shot this range 1 time before with somewhat similar results on a cardboard box.
Took 2 to dial on target. Took more adjustment this time conpared to warmer dry spring air. It was 37 deg today.
Shooting just below that far tree cluster on the middle horizon
If I can hit that well with mine when I get it done you'll be able to hear me giggle, yes, giggle from where you are.
Doing some searching here i see that temperature can have a greater impact on velocity than i originally thought and would explain why i needed approximately 2 mils more height adjustment to reach target than in the dry warm air. Seems to be a significant difference. May try testing ammo left outside vs warm ammo in my pocket to see how velocity changes with this powder
That much of a change in point of impact got me interested, so I ran some numbers through hornady's ballistic calculator. The numbers I used humidity didnt seem to matter much. Temperature made quite a bit of difference at the distance you're shooting. Denser air I guess... I use alot of RL-22 which is said to be temp sensitive, but most of my shooting is 600 or less and temperatures havent been a problem... Looks like I'll have quite a learning curve stretching my legs to 1000. Let us know if keeping the ammo warm does much, that would at least take out powder sensitivity as a variable.
I'd guess that the elevation difference you experienced was due to a combination of lower muzzle velocity from the cold ammo and more drag from the denser atmosphere.
I have gone off the deep end on mid range shooting the last couple years. (Out to about 1100 yds). I have found exactly what you speak of. Colder weather means more dense air, so more elevation is needed.
Two things I have done to account for this:
- I have switched to a temp insensitive powder. No worries about temp swings, the velocity stays the same. This is a huge deal. I cant imagine how difficult life would be having to have diff velocity data for my loads also.
- Instead of just accounting for temps changes in atmosphere conditions, I use density altitude. It takes into account all things that change how dense the air is.
Using Density Altitude (DA) has made my life easier at the 500ish -1100 yd ranges. Closer than 500 I dont see much difference based on DA. The trick is how do I calculate DA?? I dont. I use an app for my phone. I have played with this enough that I can get close based on temp and altitude where I am at. I also put together a dope card that has elev corrections for different DA's, 0 ft, 1000 ft, 3000 ft, and 5000 feet. The card looks like an insurance actuarial spreadsheet, but i have played with enough to know how it works and can use it fast. I put together the drop data on the jbm data site and pulled it all into one spread sheet. I have about ten of these data cards mixed into my gear. I also had them laminated, (after I had verified the data.)
The proof is in how repeatable this approach is.
Dam straight
Nicely done and one perdy stock to.
I ran 190s in mine.
My elk hunting partner started using 230s in his wsm this last year.
He's spot on and lethal at 1K.....couldn't shoot for sh!# past four hundred a few years ago, now he never misses. I was pretty surprised how well they have performed at modest speeds.
I did load development with my 300WM and RL-22 once. It loved all bullets! I did development in the spring and by summer, warm air temps made the load go overpressure. I happily shoot H 1000 now. Loves 190 to 210 Berger VLDs.
try H4350
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