Beyond .308 - Implications for Precision Magnums

[Gutshot John]

To set parameters: .50BMG rifles aren't where I want to be going. I'm learning Precision Rifle on an SPS and while I like the availability of parts and the ubiquitous maintainability of .308 for the weight involved I feel like there are better options in terms of precision rifle caliber.

While I'd like to keep the self-maintainable quality of a .308 in my limited experience and training I've determined that a semi-auto .308 really can do most of the things a bolt sniper gun can do and that for the time/effort/expense of a custom precision bolt-gun, I think I'd rather go with something with a bit more punch when I move beyond my SPS training wheels and also begin handloading.

The two most obvious choices are .300 Win Mag and .338 Lapua. The former is relatively affordable/available but the latter delivers some especially impressive results at distance.

With handloading the cost of .338 is less daunting and I also seem to remember hearing that .300 Win Mag barrels don't last as long as .338 but I'm not sure I can quantify that.

Is my thinking flawed?

What is missing from the equation? What else should I consider?

Given the nature of precision rifles are there other options that lend themselves to greater maintainability?

[RyanB]

7mm is much better than .30.

[jpipes]

I was in your shoes, and opted for a 6.5x47L rather than a larger magnum. With 123 Scenars at 2950 FPS, I am right at about 1.1 mils to 300 yards with excellent accuracy. I will be testing out to 600 and 1k this weekend. According to my calculations, I should be right around 7.9 mils to 1k and still be close to 1500 fps.

Really, any good 6.5 should do you well with less recoil, better barrel life, and similar ballistics to the 300 winmag. If you are wanting to go for more "punch", I would go 7wsm and not look back. Good luck.

Josh

[tylerw02]

jpipes hit the nail on the head.

The "magnums" are no longer needed with the introduction of efficient projectiles for the smaller bore rifles. We now have bullets for 6.5mm and 7mms with BCs well in excess of .600. They can be launched as fast as or faster than lower BC projectiles used in the .30s, burning less powder and producing less recoil.

I personally own a 6.5-284 Norma, a .260 Remington, and I'm in the process of building a 6.5x47 Lapua. I plan to spec the throat for 130 gr Berger VLDs. That should beat 190 gr .300 Win Mag loads to and beyond 1,000 yards. The introduction of new powders like RL17 may really expand the possibilities. I've managed 700 yard plus kills with my 6.5-284. It produces tame enough recoil I can spot my on kills and my dope to 1k is less than 25 MOA with a 28" bbl.

For a non-handloader, match grade ammunition is available for the 6.5 Creedmoore that will match .300 Win Mag trajectory for about a buck a round.

7mm cartridges can offer even more than the 6.5s with even higher BC projectiles like the 168 and 180 gr VLDs. However this will be at the cost of recoil. The 7mm WSM has proven a real long-range winner. I personally hunt with a precision rifle in 7mm---.280 Rem AI.

[Gutshot John]

Just so it's clear intention was that if you're going the route of a custom precision bolt gun, increase the range and capability of the single shot well beyond 1000 yards without having to go to a .50.

[jpipes]

Define "well beyond 1000 yards".

If you are looking at the .300 winmag, then a slew of 6.5's come very close to 300 winmag performance with significantly less powder, recoil, and barrel burning. To me, that's a win/win.

[tylerw02]

Just so it's clear intention was that if you're going the route of a custom precision bolt gun, increase the range and capability of the single shot well beyond 1000 yards without having to go to a .50.

There is nothing a .50 BMG can do that something else can't do better besides massive energy. If you're actually needing that, I wouldn't suspect you'd be asking questions here.

Look into cartridges like the .338 Edge with 300 gr Lapuas. There is word of a new Berger 300 gr VLD coming out with a BC of nearly 1.00 that will be the cat's meow.

There are guys taking 6.5-284s and 7mm WSMs to beyond 1500 yards quite consistently.

Long story short....big 6.5s, 7mms, and .338s can get you to and beyond 1500 if you do your work. Forget the .50s

[jpipes]

A good "in between" of the 300 winmag and the 338 is a 7 wsm stoked with 180 bergers or similar. I would still rather have a good 6.5 over a 300 winmag, or a good 7wsm over a .338 Lapua.

[Gutshot John]

Define "well beyond 1000 yards".

1500-1800 yards should not only be readily doable but a round that delivers decent energy beyond 1200 as well.

The 7mmWSM is an interesting option I hadn't really considered since I thought it was comparable to 300 win mag which I was really shying away from except as a commonly used magnum round with a lot of data. The 6.5 options might need some consideration.

[Jack-O]

The 300 WM really looks good for a variety of reasons when you do some math:

-the new Black hills military sniper load in 220gr matches the ballistics of the 338 Lapua 250gr
-Match grade ammo can be had for $1.50 per round
-Steyr makes a very nice 300WM sniper with removable 8 round mags and a chrome lined bore. Service life should be significantly improved. Price is very attractive at under $2k as well.
-if things got dodgy for some reason you can always go down to the hardware store and find some 300WM ammo. Try that with a 338 Lapua or 6.75x278.4 or something similar. IOW, it passes the "common caliber" test.
-reloading components are widely available, affordable, and the .308 diameter gives a LOT of options for projectiles. More than any other caliber actually.


The 7mm Magnum has a lot going for it trajectory wise. It's fairly common too, but not as flexible.


Just some thoughts.