Thank you Rex for the great information on God, Guns, and Guitars! Quick question... I found myself calculating a firing solution the other day in which I had overhead cover to deal with/avoid. A bit of an odd shot. Think of power lines. :) After a lot of searching, I could not find a calculator that produces this number. It looks as if many old school hunters used to look at mid range height, but this seems to be a rough number only viable at shorter ranges. Others state that you look at drop at 2/3 of the range. The only resource I found that definitively listed maximum ordinate for some specific loads is: www.hpbt.org/articles/308.doc I don't see anything in JBM. I don't remember you going through this in Sniper 101. Am I missing something? Thanks.
pricosurf
Oct 17For sale is a custom 7-300 win mag custom ELR rifle with Bartlein barrel and Mirage ULR chassis made by PMAC precision. Rifle comes as a package ready to go which includes a scope, custom load, confirmed DOPE to 2,550 yds, dies, bullets brass - everything you need to hit targets to 2,500 +. Avoid the 4-6 month wait for a custom builder. It has approximately 400 rounds down the tube. I took the ELR3000 course with this rifle and reliably hit targets to 2,551 (~2/5 were hits). I have a custom hand load as well as a load worked up by Copper Creek Cartridge that is sub 0.5 MOA and can be ordered direct from CCC if you are not a reloader. This is the load I used to hit out to 2,551 yds. Asking $5,995 for everything plus shipping (rifle alone is $6,700 + 6 month wait when new). I added everything up and it is well over $10,000 for everything included. Details on what is included in ELR package (happy to discuss any and all details by phone): Rifle: The rifle is a PMAC precision 7-300 win mag ( https://www.pmacprecision.com/rifle-packages ). It is essentially the same as Rex's and was built about the same time. I have heard that a rifle similarly configured has been used in field in limited circles. It has a 26 inch Bartlein heavy profile (MTU contour) barrel with a 1:8 inch twist. Action is a Stiller TAC 300 with 30 MOA scope rail. Trigger is a Jewell. Muzzle brake is an APA Gen II Fat Bastard. The chassis is a Mirage ULR chassis with an upgraded adjustable stock (the stock is awesome and has a lot of adjustment). Scope: IOR Recon 1 with 40 MM main tube. The scope tracks 100% on paper (see pics) and all the way out to 2,500 yds +. Has German Schott glass. It comes with a 40 MM American Rifle Co. 30 MOA M10 QD-L scope base ($300), a 40 MM bubble level ($34), Tenebreax cover for ocular ($38) and an objective sunshade. Reloading equipment: - Redding 7/300 win mag die set - 150 Nosler 300 win mag virgin cases - 120 RWS 300 win mag brass (virgin): this is arguably the very best 300 win mag brass and is very expensive ($41/20 and only available from one location). - 200 once fired Hornady cases from Copper Creek Cartridge loads - 150 195 gr Berger EOL bullets - 100 197 gr Sierra bullets - 100 Hornady 180 gr bullets Data/resources: - Custom Ballistic XLR ballistic data package with DOPE past 1 Mile (includes many tertiary ballistic data) - Confirmed DOPE to 2,500 https://i.imgur.com/Tg5wi2A.jpg
Racesmith,
I too have been searching for info on figuring max ordinate, so maybe Kacie will put a bug in Rex's ear for us! I'm fairly sure Rex briefly mentions it a couple of times in the series, but I can't recall where. Possibly in Advanced External Ballistics and/or the tutorial on spotting.
If I recall correctly, he said something like max ordinate would be about 60% of the distance to the target. Being able to know what that height above the ground is would be nice, especially since the 500 meter range where I shoot has been closed for nearly a year; stemming from allegations of bullets going over the back stop and hitting a barn a mile away!
I am a bit disappointed to not have received an answer in response, but I did figure out the solution. I feel a bit stupid for not figuring it out sooner. In your ballistics calculator, simply set the zero range at the target range. Look for the largest drop and that is the maximum ordinate at that range.
Racesmith,
Excellent solution! Just went to JBM's website and checked the results with the info from your earlier post. Didn't adjust all of the environmentals, but the answer was still darned close! Right around 60% of target range.
This may (or may not) help in getting our 500m range reopened.
Thanks for your post!
There is not much info out there on this topic. It would be nice to have a simple field solution to have without needing a ballistics calculator.
#Geoff Glover - At a local range I use they have an overhead backstop about 1/2 way down the range to the 200 yard line to catch those shots that are way too high. Something your range might want to consider.
Bill,
Perhaps that's in the works. Most of our board of directors got the boot in the last election, but that's a "whole 'nother kettle of fish"!