Target @ 300 Yard
01-23-2012, 03:44 PM
#16
Fork Horn
Join Date: Dec 2005
Location: My Range in Central NY
Posts: 320
Hi Ron,
Great shooting!
Air density is what I believe is messing with your drop verses dial setting. as you posted you were shooting in 9* and 15* temps. Even with your altitude being 4000+ ASL the cold temps make the air denser, warm air expands becomes lighter, cold air contracts and becomes heavier. The cold denser air creates a great deal more resistance for your somewhat less than streamlined projectiles.
I know that 50BMGs are not muzzleloaders but can I be allowed some leaniance in using one of mine as an example of how air temps (air density ) affect bullet drop.
At the family farm we have a 1000 yard range, we regularly enjoy shooting various firearms at great distance.
On an average summer day some where around 70*+ - my chosen loads will require 38 to 39 " of elevation adjustment to be right on our 1000 yard gongs. We shoot more in the winter than summer because of free time and such. At 32* +- shooting same loads, same rifle, same projectile, same scope, same set up, bench, muzzle brake. even same shooters, it will take a minimum of 44 " of dialed in adjustment to be right on the same gongs. This example is with a very High BC projectile compared to a Blunt Pistoly Boolit.
I believe Ron that this summer if you get the chance to set up in the same spot you will be amazed how much better that Pistoly Boolet pushes threw the air. You Dials will probably be very close.
Great shooting,
Ken
PS: There is a very good chance I will be visiting Rapid City this coming Spring/Summer. Just a warning! The Wife and I just haven't decided on a date yet.
Great shooting!
Air density is what I believe is messing with your drop verses dial setting. as you posted you were shooting in 9* and 15* temps. Even with your altitude being 4000+ ASL the cold temps make the air denser, warm air expands becomes lighter, cold air contracts and becomes heavier. The cold denser air creates a great deal more resistance for your somewhat less than streamlined projectiles.
I know that 50BMGs are not muzzleloaders but can I be allowed some leaniance in using one of mine as an example of how air temps (air density ) affect bullet drop.
At the family farm we have a 1000 yard range, we regularly enjoy shooting various firearms at great distance.
On an average summer day some where around 70*+ - my chosen loads will require 38 to 39 " of elevation adjustment to be right on our 1000 yard gongs. We shoot more in the winter than summer because of free time and such. At 32* +- shooting same loads, same rifle, same projectile, same scope, same set up, bench, muzzle brake. even same shooters, it will take a minimum of 44 " of dialed in adjustment to be right on the same gongs. This example is with a very High BC projectile compared to a Blunt Pistoly Boolit.
I believe Ron that this summer if you get the chance to set up in the same spot you will be amazed how much better that Pistoly Boolet pushes threw the air. You Dials will probably be very close.
Great shooting,
Ken
PS: There is a very good chance I will be visiting Rapid City this coming Spring/Summer. Just a warning! The Wife and I just haven't decided on a date yet.
01-23-2012, 05:00 PM
#18
Nontypical Buck
Thread Starter
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
After reading about the cds dial, i ran my favorite load through a chronograph a few different days, and using different rifle. When a muzzle velocity was established in my mind, i ordered dials from Leupold. For the X7, a dial engraved for a 1885 fps muzzle velocity was ordered. For Longer barreled rifles, dial for 1910 fps, and 1925 fps muzzle velocity were ordered.
It amazed me that i could sight in the rifles at 100, and 200 yard, then set target, or water jugs out beyond that, and readily hit where i aimed. The dial for whatever rifle, would land bullets into the target virtually first time every time. It was kinda surprising that Leupold could use the muzzle velocity i sent, along with the bullet information, which was ballistic coefficient, and bullet weight and name, to engrave the dial so it was amazingly accurate for the actual long range shooting i did.
What i used for a load in every case was 300g Deep Curl bullet, and 110 of BH209. Last week, i was using a dial engraved for a mv of 1925. When i shot at jug placed at 300 yard, the bullet seemed to hit low. I figured that the bullet wasn't starting as fast as i measured last summer, so i added more powder so to increase the muzzle velocity. It seemed to work, because today the bullet flight seemed to match the dial i ordered. However, Ken suggested the bullets may have fallen short because of the air being more dense.
What ever the reason, i intentionally ordered dials made for 110g of powder. The reason i did this was so if the bullets fell short, i could add powder, and hopefully get them to fly, in the winter, the same they flew in the summer. It seemed to work today, but it seems to me, much much more shooting is required, before a conclusion is reached. Did you catch that? More shooting is required! Aw shucks.
01-23-2012, 05:27 PM
#19
Nontypical Buck
Thread Starter
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
