7mm or .308?

[sjvcon]

Buy both ... problem solved!!!!!!!!!!

[nralifer]

One needs to compare roughly equivalent cartridges. Thus a fair comparison is the 280 and 3006 using bullets of equivalent BC and muzzle velocity. Thus the Nosler 7mm 140gr Accubond and the .308 165gr Accubond bullets launched at 2800 fps differ by less than 1 inch drop at 500 yds but the .308 bullet arrives with 200 ft-lbs more energy. Viewed this way, the .308 bullet has the edge

[ruffcountry]

luv my 7 rem mag . for some reason never could get excited bout 308 win .

[Toad]

One needs to compare roughly equivalent cartridges. Thus a fair comparison is the 280 and 3006 using bullets of equivalent BC and muzzle velocity. Thus the Nosler 7mm 140gr Accubond and the .308 165gr Accubond bullets launched at 2800 fps differ by less than 1 inch drop at 500 yds but the .308 bullet arrives with 200 ft-lbs more energy. Viewed this way, the .308 bullet has the edge

I think this view has more to do with weight of the bullet then the caliber. Of course the heavier bullet going the same speed as the lighter one will have more energy. I would say the .284 has the edge because in your comparison you threw all the advantages the .284 has (bc and velocity) out the window.

[nralifer]

Lets look at the 180 30cal bullet and the 175 7mm bullet. In the 3006 Hornady Superformance loads propel this bullet at over 2800 fps. They do not make a load for the 175 gr 280. The difference in BC gives a slight edge to the 7mm bullet, but this is less than 10%. At long ranges this is not noticeable. As bullet weight increases the larger caliber will be able to propel the heavier bullets faster which can more than make up for small differences in BC. At some point the smaller caliber heavy bullets get so long that tighter twist rates are needed to stabilize them, and this starts to limit the muzzle velocity achievable with peak pressures of 65,000 PSI, pressures that exceed most SAMI specs

[Havasuhunter]

I thought the original post was asking if a 7-08 or a 308 was better. You guys refer to 7mag like it the only 7mm made. 7-08, 280 rem7x57 Mauser are all great and I would choose them over a 308. 7 rem mag is just an awesome long range cartridge and out classes all of them. A friend of mine absolutely loves his 7mm WSM too. 270 or 270wsm are great as well. You would do well to choose any of them. If elk is in the mix the 7 rem mag would be my choice over all of them. 7 mags recoil is nothing too, at least to me. I think a good old 270 win will do anything I need it to do though. The old more bullets available argument is moot unless you are a competition shooter constantly playing with loads. Plenty of great bullets for a 270 or 280(7mm).

[nralifer]

I never thought a whole lot about the 308 Win either until a friend of mine turned me on to it. He was a sniper in Vietnam and told me about several kills he made at over 600 yds with the 308 using an M14. Unlike the Marines who used 30-06 bolt guns, at that time Army snipers did not have as good equipment. I figured he knew what he was doing since he hunted the most dangerous "game" in the world. I have used the 308 on plains game and antelope out to 500 yds. My absolute favorite hunting rifle is a Savage actioned 308 with a Douglas 20 in. match bull barrel. The gun is compact, rugged and shoots 1/2 min of angle or less all day. Easy to get in and out of vehiles and is light enough to carry all day. It is absolutely wonderful for shooting hogs in heavy brush.

[nralifer]

I will have to admit, I have never met a gun I din't like, and that includes 7mm's. The difference between a "7mm" and a .308 is actually only 0.4 mm. Modern rifles are precision instruments to be admired for their capabilities and respected for their lethality. In the end probably more elephants have been killed with a 7X57 than a 458 Lott, but no one would argue which is better at stopping a charging bull. SJVCON has the right idea, "Buy them both…problem solved!!!"

[nralifer]

The 270 has great untapped potential. I have been using the Superformance powder and shooting Barnes TSX bullets. I got a 26in Benchmark barrel with a 5 grove 1:9 twist. Today explored the limits of velocity with the 140gr TSX. Has a BC of 0.404. Got it to shoot 3200 fps and at 500 yds this bullet still has 1364 ft-lbs of energy. It is still supersonic at 1000 yds. With this powder and the right barrel length the 270Win is virtually the equivalent of the average 7mmRem Mag. One can verify the trajectory using the trajectory calculator on shooterscalculator.com

[roninflag]

i would ask what rifle ? what are you shooting at?

[208muley]

Off topic a little but I shoot a 280 ackley and love it. Very similar to a 7mm but doesn't hurt at all 20-30 shots latter. It's flat out accurate to 800 and at .4 moa 5 shot on avg with factory, yes factory, ammo I think it's good enough for me. Oh yea I didn't spend 5-7k to get the gun either. But, on topic, I would listen to anything 308nut says. Smart is an understatement. Just saying.

[catfish campbell]

7mm08....check out the ballistics

[STOMP442]

Similar cartridges like the 7 mag or 300 win mag, 7-08 or 308 or .270,.280 or 30-06 need to be compared the same way. A 150 grain bullet in a 270 is a heavy for caliber bullet. A 150gr bullet in 7mm is a middle weight at best and 150gr in a 30 cal is a light weight. To accurately compare cartridges you need to use heavy for caliber bullets in all of them. A heavier bullet maximizes potential of the caliber and why a 270 shooting 150s can be made to look like it can perform just as well or better than larger calibers. Make comparisons with 7mm bullets in 168-180gr weights and 30 cal bullets in 200+ grain weights. Also make sure to compare using similar bullet styles and accurate BCs.

[Havasuhunter]

Similar cartridges like the 7 mag or 300 win mag, 7-08 or 308 or .270,.280 or 30-06 need to be compared the same way. A 150 grain bullet in a 270 is a heavy for caliber bullet. A 150gr bullet in 7mm is a middle weight at best and 150gr in a 30 cal is a light weight. To accurately compare cartridges you need to use heavy for caliber bullets in all of them. A heavier bullet maximizes potential of the caliber and why a 270 shooting 150s can be made to look like it can perform just as well or better than larger calibers. Make comparisons with 7mm bullets in 168-180gr weights and 30 cal bullets in 200+ grain weights. Also make sure to compare using similar bullet styles and accurate BCs.

Well said. Comparing 7mm rem mag to 308 is like saying should I buy the mini van or the 1 ton diesel. It depends what your using it for. when someone says 7mm, I think of 7-08 or 280 rem. The 7 rem mag is an awesome long range high powered cartridge which is why so many custom long range rifles are build around it.

[STOMP442]

The 270 has great untapped potential. I have been using the Superformance powder and shooting Barnes TSX bullets. I got a 26in Benchmark barrel with a 5 grove 1:9 twist. Today explored the limits of velocity with the 140gr TSX. Has a BC of 0.404. Got it to shoot 3200 fps and at 500 yds this bullet still has 1364 ft-lbs of energy. It is still supersonic at 1000 yds. With this powder and the right barrel length the 270Win is virtually the equivalent of the average 7mmRem Mag. One can verify the trajectory using the trajectory calculator on shooterscalculator.com

Barnes bullets have just about the worst BC possible especially in their 7mm offerings which are only flat base on top of that. Use any other bullet but Barnes in 168gr or heavier and the 7mm mag will walk all over the 270. heck even a high BC 140 in 7mm will out perform your 140 Barnes at 3200 fps.

 

I have nothing but great things to say about a 270 but to call it the equivalent of a 7mm mag is just wrong.