I was thinking you might have a long barrel rifle. Your goal of achieving higher velocity compared to my 20-inche carbine barrel is easier to reach. I think a target velocity of 2600 feet per second is reachable.
I have not fired over the Chrony with my 30-30 but I have with a .300 Savage 24-inch barreled Remington M722. A factory load that is advertised at 2670 fps gives an average of 2430 fps at 6700-foot elevation. I have experience similar reductions in actual velocity with some factory .270 ammo. At the same location I am achieving 2670 fps with a 165-grain bullet. Like you I am trying to get a little more from an old factory round. My load is still within the publish maximum in the Hornady manual.
Hornady has listed a 130-grain Spire Point bullet in .308 since Charlton Heston parted the waters of the Red Sea. A couple of my childhood friend’s father was a County Trapper. His work and fun rifle was a Savage 99, which he used on all kinds of critters including a few black bear every year. His load consisted of the Hornady 130-grain bullet pushed by surplus 4895. The point being the bullet has a proven track record on game up to and including deer and bear. Hornady list the 130-grain bullet for varmints and medium game. I have a box of them
Speer also offers a couple of 130-grain bullets in .308. Speer also warns against hot loads in the thin wall 30-30 cases in bolt-action rifles such as the Remington 788. The cases are the issue, not the bolt-action rifle.
http://www.midsouthshooterssupply.com/item.asp?sku=000033020“I am actually starting low and working up. If I want to use this rifle and cartridge in Scotland the velocity needs to be 2450fps minimum and producing a minimum muzzle energy of 1700 ftlbs now allowing for temperature and load variations to be safe I need to get at least 2600 fps”
Two items may give you the best bang for the pound, a Chrony, and Sierra Bullets Infinity software. The Sierra software gives you a wide selection of bullets from different manufactures to compute the results you obtain from your Chrony. According to the Sierra program the 130-grain Hornady bullet will give 1951 pounds of energy at muzzle with the 2600 fps muzzle velocity. I use these two products to judge my loads and I think they have enhanced the experience over the years.
The Hornady 150-grain round nose at 2400 feet per second will give 1918 of energy at muzzle out of a 20-inch barrel. In theory you should gain 20 feet per second or more velocity per additional inch of barrel. A muzzle velocity of 2450 fps will give you 1998.9 foot-pounds of energy.
You are efforts with the bolt action 30-30 in a sense parallel my efforts with a bolt action .300 Savage. The base round in both cases are around older lever action rifles. I have taken my rifle to the published maximum and stopped. I have found some data that indicates that I can add more powder and achieve slightly higher velocities. But I have decided to stop where I am.
I have admired the pictures of you rifles that you have posted so I know you have a number of options. You can easily meet the standards for the hunt; it comes back to how far you want to push the case, and the rifle.