I too think that the 8mm is a "cool" round. I reload for it and enjoy good performance with it in several military Mausers and with a Sporterized (in Germany) Mauser Model 98.

On the other hand, most of my hunting experience in the US and in Africa has been with the old Ought-Six. There is a plethora of high-performance bullets available for the old war horse and if you are a hunter, that may tip the scales for you.

I really like the CZ rifles and one in 8mm might just be the "cat's meow."

My sporterized Model 98.

 

I am located on the other side of the Atlantic so bullet choise isnt really a concern. I mostly load Fox classic hunter and peregrines. Both monolithics.

I started my career with a Sako A3 FS in 30-06 wich i later traded in for a l61r in 30-06 to get a bit more barrel. used that for 2 seasons then decided to sell it as the Sako just never fit me right and i didnt want to modify a classic stock to suit my frame.

Currently shooting a 6.5x55 CZ550 and mostly liking it but it does seem to lack a little oomph down range compared to the 30-06 wich is both good and bad depending on the situation and target. 6.5x55 is moose legal here and will definitely take them down, same for deer but it doesnt leave mutch of a blood trail in many cases.

I am solely a hunter. Or at least until recently... nepotistic bastards kicked me out of the hunting club to make room for someones family member and no club means no hunting grounds... Currently shopping for a new club.

 

Being in the US I easily lean towards the .30-06, especially for a new rifle purchase. Ammo is easy to find and available in a range of prices, bullet weight, type and brand. As a reloader bullet selection is better for the .30's than 8mm's. Either cartridge is suitable for hunting and I wouldn't feel hampered with the .30-06 or 8mm.

FYI - Here in the US we see the "JS" and rarely the "IS" you've used. You might get asked about it for those unfamiliar. I think it was a translation matter from German to English that stuck before it could be corrected.

 

JS doesnt mean anything. IS means infanterie spitzgeschuß. For those who come across this and dont know. Its indeed a translating error Specifically misreading of german font.

I was infantry
R rimmed, later marked IR
M for marine(navy) wich as far as i know never became a thing because of logistics
S stands for spitzer bur mire relevantly marks the transition to the bigger diameter bullet.

So ballistically not too mutch of a difference then?

 

Adding another factor into the mix, these rifles come threaded for a supressor with 20" barrels. I wonder if this favors the 8mm more with regard to powder burn efficiency and supressor fouling.

 

Both are great choices with nearly identical performance. The 8mm handles heavier bullets well and has cool factor. The .30-06 wins on ammo availability and variety.
Since you already like the .30-06, it's the practical pick. But if you want something unique, the 8mm is a solid and interesting alternative.

 

I shot my first deer with a sporterized 8x57 Mauser. I did not make a stellar shot, but that Remington Core lock sure put Bambi down for the count. If I weren't using my favorite Mauser round these days for deer in the forests of PA, most likely I'd be using an 8mm Mauser. Hits like the proverbial freight train, punches a bit bigger hole, and doesn't beat you up too badly. Plus it'd work for any critter that I'm interested in hunting in North America at least.

 

They are twins.

Buy what feeds your "cool" factor.

 

At least here in the US there is a much wider variety of bullet weights in .308 diameter vs 8mm .. based on that alone I would go with '06. But if you dont have the wide variety then the 8mm doesnt lose much if anything and so it becomes more of a coin toss

 

other than wide variety i usually look at bullets it like. And my favorite manufacturers are european and cater specifically to our cartridges. I think they arent even available in the US. So its a bit of a flipped scenario, 308 bullets come in all shapes and sizes on both continents, but a lot of less usual ones like .311 and 8mm are offered exclusively here.

Been intrigued by those oddball cartridges as well (not so odd back in their day) like a sauer in 6.5x68

as a tangent, that seems like it would be a pretty insane cartridge!

nearly 90gr powder capacity, 1:11 twist .264 bullet, typically 90gr-140gr runs at 64.000psi
Hard to find loads tho. Basically a 6.5mm version of 22-250.

 

For longer range shots and higher BC I'll always take the -06.

 

Since you already like .30-06 but find the 8mm cool - go with the 8x57IS! That "cool factor" makes shooting more enjoyable, and the performance difference is negligible for deer hunting.