I have finally decided to build a custom long range hunting rifle and cant really decide on the best caliber. This rifle will be used for elk, muleys, kudu, and at least once on an eland (if the good Lord is willing). I have some what narrowed my list down to the .300 Win Mag and the 7mm Allen Mag. I am 5'10" and 160 lbs so I am concerned with recoil. The rifle should not exceed 9 lbs and 26" barrel so as to make it more friendly on my mountain hunts. My Kimber .325 WSM has a sharp recoil but I can manage it well (I think I can shoot better than this particular rifle!) The 7mm AM should be sufficient on the large eland with 175 grainers out to 500+ I would think, certainly adequate for the other large critters. I like the .300 for 200 and 220 grainer capability but my all purpose load wiould be the 180 grainer. SO..., is there any other calibers that you would recommend? Thoughts, comments, suggestion?
HELP! Thanks in advance.
------------------------------------------------ Double taps are for Wussies...
There are plenty of reasons to get either. For decades, many who prefer to be a "one gun" hunter choose the venerable 300 WM, and for good reason. It simply works and works well. The hole is bigger, the bullet wt selection is heavier, it is a very accurate caliber. It is an excellent choice.
I do not have personal knowledge of the 7AM other than what I've read here. It appears to be an excellent choice for a do-all rifle. To be blunt, if a 140 Berger VLD from a 6.5x284 can dump a bull elk at 900+ yards, there's nothing either of your two choices can't do better.
If you are to travel across the world to hunt, you can find 300 WM ammo just about anywhere. Not so with the AM. So, if you go on a hunt of a lifetime and your 7mm AM ammo is a no show, you are out of luck. I guess that would be the only downside of any wildcat or semi-uncommon caliber.
Kirby built a rifle for me in 270AM and did an excellent job. The rifle shoots very well.
I own a 7AM and for the purposes you describe, it hardly sounds like the cartridge of choice. It is best with a lot of barrel length to burn all of the powder. A 7mm AM is the ultimate ultra-long range 7mm. Kirby has a "small" green stocked 7AM he hunts with a lot and I do not know the weight of it. Maybe it meets your criteria. For a under 600 yard rifle for elk sized animals it would seem to me that the slightly smaller 7mm's would be easier to build a rifle to meet your specification and do the job just as well. I killed a near B&C wild bison with a 7 Wby. I don't think an eland or kudu is bigger than that.
So, if it was me and I was building a rifle for shooting animals under 1000 yards a 7STW is what I would compare to a 300 WM. I am a fan of the 7mm but I personally don't see much difference in killing ability of the two cartridges at the ranges you talk about.
Kirby does build a lot of rifles that are not Allen Mags, so it is not like he can't put in whatever chamber you would like.
i basically agree with everything said. my concept of a 7AM is it's a serious long range cartridge. my gut feeling is you don't have much experience with long range and i wouldn't recommend a 7AM. the 300WM is also a great cartridge, can do everything you want.
my suggestion would be to use the 325WSM. it will also do everything you want. bullet selection is not as good but you can probably find something that will work well. get the gun accurized and shoot it a year or so. then decide what you want to build.