7mm-08 vs 308

bmicek

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Alright, I know they’re close and both will be effective. My current dilemma is I have two Kimber rifles, one Adirondack 7mm-08 and one Subalpine in 308. For the sake of this question, let’s just say they both weigh the same but the Adirondack is 18” and the 308 is 22”.

My goal for this particular hunting rifle is a super light deer/antelope hunting rifle inside 500yds. So if I kept the 308 I’d chop it to 18-20” to keep it compact (I use a suppressor).

Now I know weight for weight the 7mm-08 will have a higher BC but to me that doesn’t play a massive role inside 500 and more likely inside 350. I can’t think of any great reason to stick with the 7mm-08, and instead switch to 308. I’d like opinions and maybe it’ll just be one of those deals that neither is the wrong choice, which I’m pretty that’s the deal here.

Also I was thinking cartridge efficiency may play a role in the decision. It’s said a larger diameter bullet is more efficient so although a 7mm-08 may have a higher BC bullet of the same weight, would the 308 have a slight velocity edge giving them no real edge over each other?
 
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bmicek

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I feel dumb even asking because they’re both gonna do the job well. Just one of those deals where I’m in a good position to have a good rifle either way and don’t want to regret getting rid of one. And keeping both isn’t an option since they both overlap so much.
 

TN2shot07

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I have both in Model 7’s and the only advantage the 308 has for me is ammo options (I don’t reload). The 308 is one of the kuiu versions with a 16.5 inch barrel, the 7-08 has an 18. If I’m sticking with one it’s the 7-08. I may also be interested in that Kimber if you decide to off load it!
 

TheGDog

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Well... there is the potential point to consider of retaining both and taking them both with you on a hunt, so you can leave one in the truck, just in case who-knows-what happens and like, for example the optic gets damaged on the one you had out with you in the field.

Also you can loan it if you had an acquaintance that wanted to go into the field with you, but didn't have a rifle handy, such as a relative visiting.
 
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bmicek

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When I think of antelope, I think of windy country.
Shooting 350+ in wind, I'll take the higher BC bullet, and that points to 7-08, not to mention less recoil.
I think you’re right but is there an efficiency benefit to the 308 having a larger base bullet which would offset the high BC?

Kinda what I’m asking is if you shot a 140gr bullet from a 7mm-08 and a 140gr bullet from a 308, the 7mm bullet would likely have a higher BC but will a 308 be slightly faster because it’s more efficient? Therefore offsetting the higher BC being an advantage. I don’t know the answer to that BTW. But it’s said a 338 Federal will shoot a bullet of the same weight ~200fps faster than a 308 of the same weight. I don’t know how much that transfers when comparing 7mm-08 to 308 but it very well could mean the high BC of the 7mm-08 is negated by the faster 308 of the same weight (when comparing same bullet weights).
 
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Trogon

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There is no such thing as "Efficiency" related to barrel length. More barrel, more powder, more faster. Get your MV for those two guns and plug your data into a ballistic calculator and make your decision. 308 is a rainbow, so I'd take pretty much anything over that.
 
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bmicek

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There is no such thing as "Efficiency" related to barrel length. More barrel, more powder, more faster. Get your MV for those two guns and plug your data into a ballistic calculator and make your decision. 308 is a rainbow, so I'd take pretty much anything over that.
Not efficiency in barrel length, but cartridge specific. Same concept as a bored engine. More surface area on a larger bored piston=more displacement.
 

hiker270

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Very little difference in the two as was stated above. Pick the one that jumps out at you and says take me.
 

Macintosh

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If youre loading for both, do you have comparable-bullet mv from your rifles? Id plug those numbers in and see what your app says at range. Guessing the individual rifle and bc will make more of a difference than the bullet diameter, so I doubt anyone but you can make the call based on anything more than conjecture.
 
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bmicek

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If youre loading for both, do you have comparable-bullet mv from your rifles? Id plug those numbers in and see what your app says at range. Guessing the individual rifle and bc will make more of a difference than the bullet diameter, so I doubt anyone but you can make the call based on anything more than conjecture.
Sadly I don’t have comparable data. One rifle is unfired by me, the other has about 5 rounds through it by me. I knew my question was probably not gonna get a clear answer just on account of them being so closely comparable
 

taskswap

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I've got a Browning X-Bolt in 30-06 with a 24" barrel (26" with the muzzle brake) that I absolutely love and will take down any north american game I care to go after. But I never hunt with it - I took my last two elk with a Savage 110 in 7mm-08. (Using Hornady Precision Hunter 150gr ELD-X if anybody cares.)

Why? The 20" carbine is smaller and lighter which makes it a pleasure to carry and more nimble scrambling through gambel oak or sage. The 7mm-08 has a very low felt-recoil while still being absolutely enough (without the right load) to take elk at 300-500yds. It's the same caliber my wife shoots so I can stock a common ammo for both of us. And it shoots very flat. What's not to love?

308 is a great round too. I think this is sort of a religious debate. But for my money, I'm very happy with what I have.
 
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