Yes Westwinds make all their Ventile Jackets to your order...so you can customise their standard range. E-mail would be better than calling them.

Good luck with the .308...there is plenty of info on this calibre so you should find the ability to learn with this easily done...Plaster's book is good with this calibre...but it is not an easy calibre to shoot well at long range. At 1000 yards a good .308 HPBT will move 1 MOA for every 1mph of full value cross wind...that is 10 inches...and it is hard to pick up wind changes in 3 mph increases when it is blowing...but at lower wind changes Mirage is your friend.

Good Luck...if you master the .308...the rest is easier...the .338 LM will seem much less troublesome to make wind calls with in comparison.