This will be my first venture into a long range hunting rifle and I seek advice of forum members. But first let me set the scene:
I already have a .308 Norma Mag, custom built for me in the late 70s early 80s, see pick below:
But it was built as a classic hunting rifle rather than a dedicated long range rig. I haven't shot it that much in recent years but threw some loads together recently using ADI AR2209 (packaged and sold in US as H4350) with 180 gr Hornady SPBT and chronographed 3,175 fps average (this load was a bit hot so would probably pull back ½ grain to around 3,150 fps) out of its 24" Douglas premium barrel. Groups were not all that good but my gear needs some updating and haven't shot a rifle all year so I am very rusty. These loads encouraged me enough to ear mark them for further work and probably would try some 180 gr SSTs and 178 gr A-Max too. So I will be doing considerable further load development for this rifle.
Here's my question on long range calibre. I have identified that I want another rifle, probably SS/synthetic, for this (could be factory or custom as my brother-in-law is also my gunsmith) but I need to decide on the calibre first. What are the uses you might ask?
As I live in Australia, nothing more then a Elk size, largest deer we have here is Sambar but it could double as a rifle for water buffalo in the Northern Territory (NT) with the right bullets. Of course thhis would not be at long range (so the rifle may be multi-misson). The guy who built my .308NM did a number of this calibre for NT buffalo hunters.
I also want to do a bit more overseas hunting (first O/S hunt was last year to New Zealand for Tahr and Chamois and took my M70 .270 Win fwt for that).
I was thinking of a .300 Win Mag (don't really need/want to go to the ultra mags, et al) but with doing some load development for my .308 NM thought that if I made the new rifle a 30-338 WM (almost identical to the .308 NM) would have the following advantages:
> the experience there could be readily transferred with the usual caution of course to the new rifle's load development. Where as if I got a .300 WM the dynamics are sufficiently different for it to be a whole new load development process
> the 30-338 would enjoy economies of scale in my powder inventory as my .270 win shoot best with this powder too. Whereas I notice the .300 WM does best with slower burning powders like H1000 or even Retumbo (with bullets 180gr or heavier).
> Additionally, in support of the 30-338 I enjoy calibres that are a bit different and I like the efficiency of this and the .308 NM
> plus with the heavy bullets I plan to load the 178-180 Hornadys (as mentioned above) mostly and for a heavier bullet, the 208 gr A-Max. I figure the 30-338 would better fit most actions (I have a FN Mauser 98 action in my gun safe) as far a proper seating of big bullets for maximum MV and accuracy
On the other side (of the balance sheet) the .300 Win would have the following advantages:
> more standard calibre and more available and variety of brass
> I like to have proper headstampted brass and my research shows only Quality make 30-338 cases
> I can get any number of factory rifles in .300 WM, whereas the 30-338 would be also certainly a custom build
Oh, the distance I would be most likely to shoot, not having done a lot of LR shooting, probably 500- 800 yards and even then after a lot of practice and skill acquisition in this area.
A bit of info on the rifle I want to get/build:
< or = 8.5 lbs max (as I want to carry it up the hills)
Prefer a non braked rifle but this could be fitted (preferably a removable one)
All input appreciated. But let me tell you I am pretty set on a .30 cal