7mm08 vs 308

[rem sendero]

what are the pros and cons of each? I need to decide which one I want. does anyone have a a 7mm08 that has a 1-8 twist for shooting 180gr bergers?



www.minuteofangle.blogspot.com

 

[RonAKA]

Just my observations. I think the .308 case is a bit small for a 30 cal, and the 7mm is better sized bore for the case. Also some nice high BC bullets in the 7mm caliber that are not so heavy. The 7mm-08 would be my choice of the two.

 

[jonbearman]

I have just converted to a 7-08.Mainly for recoil control and the fact that there are so many bullet combo's you can use.Shooting the heavies in your fast twist should be a winner.I watched a guy who built a mauser with an adams&bennett barrel(not the highest quality) and sold me when I saw him shooting match bullets that were 168 grain I believe.I laughed when I saw his old mauser drill a hole at only a hundred yards.I was bit as I have been a fan of the .308 for a long time.I bought an encore pistol,and now I am doing a build in 7-08.I cant wait.I vote for the 7-08 with lapua necked down .308.

 

[HillbillySniper]

7mm08 would be my choice as well as ron stated better BC bullets with not a ton of wieght to them. All around good hunting caliber. I'm looking into making a 7mm08 AI to shoot the 162 Amax as a hunting gun.

Hillbilly

 

[ollie]

I would also go with the 7-08. The only thing i would do different from the above posts is neck up 260 lapua brass. easier to expand than contract.

 

[AckleymanII]

7/08 is blown off a lot less and drops a lot less...

For deer, the 130g Speer SpBT with IMR 4895 and 9 1/2 is killer on deer out to 325, which is as far as we have killed them.

 

[rem sendero]

thanks for the feedback.

 

[treeman]

my friend just finished a 284 with 1-9 twist and put 5 berger 180's in 2-1/2" at 500 meters (547 yrds)
I don't think you will have to have 1-8 twst to shoot the heavies

 

[rpierce]

I would think he might need the 1:8 since the 7mm08 wouldnt push the heavies/180 anywhere close to the .284. Most .284s are pushing them 2850-2900fps. I would think trying to shoot the 180s out of the 7mm08 would be a waste since the velocity would be so low that the ballistic advantage would not be there. If theres no advantage why pay the 40.00 a box. The 168vld or 162amax would probably be better suited for the 7mm08. Just my opinion. Maybe someone else could chime in on what they think.

 

[RonAKA]

You only need a 1 in 9 for the Berger 180 in 7mm, and 1 in 10 for the 168 according to Berger. Not sure if there would be any advantage of going to the 180 either.

 

[rem sendero]

don't people shoot the 210 gr vlds and matchkngs out of the 308? wouldn't that be close to the same?

 

[RonAKA]

don't people shoot the 210 gr vlds and matchkngs out of the 308? wouldn't that be close to the same?

Not sure what you mean by the same. At the link below, on the lower chart you can see the stability factor of a 180 gr. Berger VLD vs velocity in a 9 twist. It is about 1.22 at 2500 fps that you should get with a 7mm-08. That is cutting it close but should be good. The other 180 grain Berger is shorter, so it will be fine. Still think it will probably be too heavy to be ideal for accuracy. The 168 should do really well, and only needs a 1 in 10 twist.

Berger 180 VLD Stability in 1 in 9 twist

 

[Laurie]

rem sendero,

you don't say what you plan to use the ammo for. Everybody has assumed target shooting, but there is a Berger 7mm Hunting VLD listed as well as the match version, so it could be long-range hunting as well as / instead of range use?

What length barrel are you planning on using?

Finally, if target shooting do you have any discipline in mind and over what distances? I ask that as 7mm-08 is a fine short to mid range cartridge for any calibre disciplines, but outclassed for long-range F-Class when up against larger numbers such as the 6.5-284, 7mm WSM and SAUM. .308W on the other hand has its own class (F/TR) within the discipline shared only with .223 Rem, making it easier to be competitive using it within its niche.

In both choices, using heavy bullets for the relevant cartridge (175/180 7mm and 185-210 0.308"), correct barrel throating to suit long bullets is essential to get maximum performance, both cartridges being seriously limited at 2.800-2.810" COALs. This applies particularly to the 7mm-08 with 180s which are very long bullets. With a standard SAAMI 7mm-08 throat, I'd agree with previous comment that it's unikely the 180VLD will give best performance, but it may be very different if you can seat it right out to 3.100" which still has 0.24" of bullet shank gripped by the neck. At the standard 2.8" COAL. you have over three-quarters of an inch of bullet inside the case taking its base way down below the case-body to neck junction which is very undesirable.

Running the 180gn VLD through QuickLOAD, at 2.8" COAL you can get 2,598 fps from 41.5gn N550 and near max case fill from a 26" barrel, the estimated MV rising to 2,665 fps from a 30" barrel.

At 3.1" COAL, you can safely increase the charge to just over 44.5gn N550, again a 97 or 98% fill-ratio for 2,648 fps from 26" and 2,720 fps from 30".

While 150-200 fps down on suitably throated .284 Win rifles with equivalent barrel lengths, a potential MV of 2,700 + fps from the 180gn VLD with its 0.337 G7 BC is not to be sneezed at. The Berger 210gn 0.308" VLD has a similar BC (0.323), but you won't safely get a 2,700 fps odd MV out of a .308W rifle - and you'll get a heck of a lot more recoil and torque.

Laurie,
York, England

 

[rem sendero]

rem sendero,

you don't say what you plan to use the ammo for. Everybody has assumed target shooting, but there is a Berger 7mm Hunting VLD listed as well as the match version, so it could be long-range hunting as well as / instead of range use?

What length barrel are you planning on using?

Finally, if target shooting do you have any discipline in mind and over what distances? I ask that as 7mm-08 is a fine short to mid range cartridge for any calibre disciplines, but outclassed for long-range F-Class when up against larger numbers such as the 6.5-284, 7mm WSM and SAUM. .308W on the other hand has its own class (F/TR) within the discipline shared only with .223 Rem, making it easier to be competitive using it within its niche.

In both choices, using heavy bullets for the relevant cartridge (175/180 7mm and 185-210 0.308"), correct barrel throating to suit long bullets is essential to get maximum performance, both cartridges being seriously limited at 2.800-2.810" COALs. This applies particularly to the 7mm-08 with 180s which are very long bullets. With a standard SAAMI 7mm-08 throat, I'd agree with previous comment that it's unikely the 180VLD will give best performance, but it may be very different if you can seat it right out to 3.100" which still has 0.24" of bullet shank gripped by the neck. At the standard 2.8" COAL. you have over three-quarters of an inch of bullet inside the case taking its base way down below the case-body to neck junction which is very undesirable.

Running the 180gn VLD through QuickLOAD, at 2.8" COAL you can get 2,598 fps from 41.5gn N550 and near max case fill from a 26" barrel, the estimated MV rising to 2,665 fps from a 30" barrel.

At 3.1" COAL, you can safely increase the charge to just over 44.5gn N550, again a 97 or 98% fill-ratio for 2,648 fps from 26" and 2,720 fps from 30".

While 150-200 fps down on suitably throated .284 Win rifles with equivalent barrel lengths, a potential MV of 2,700 + fps from the 180gn VLD with its 0.337 G7 BC is not to be sneezed at. The Berger 210gn 0.308" VLD has a similar BC (0.323), but you won't safely get a 2,700 fps odd MV out of a .308W rifle - and you'll get a heck of a lot more recoil and torque.

Laurie,
York, England

wow that is a lot of info. I want a rifle that is friendly to shoot and accurate also I would like a gun that will take down a deer at 500+ yards. I currently shoot a 300 RUM and it kicks a lot, but shoots great. I want a rifle that shoots extremely well (1/2 MOA or better) that isn't to expensive to shoot. I am trying to decide between the 7-08 308 and (6.5 284 I'm only concerned about barrel life with this one)

 

[jonbearman]

The 7-08 and 308 are not real hard on barrels however the 6.5x284 is a known oxy-acetelene torch.I would stay away from that 6.5 if barrel life is any concern at all.

 

[flatlander]

I'm working up loads & fireforming 7mm-08 AR30 brass in an AR10 built on JD Machine receivers, with a 25" Krieger 1:10tw. bbl. This is my first experience with the 7mm-08 in any form - this one's got a 30* shoulder instead of 20*, and the body's blown forward .065", so case capacity should be marginally larger than a std. 7-08.

So far (I'm just getting started with the project), all of the loads with S168MKs have averaged under 2400fps, yet wind drift at 600yds. has been surprisingly small, considering that I'm used to shooting 6mm 115s at 3000, 6.5mm 130VLDs at 2900+, and 7mm 180VLDs at 2800+. I've got enough FF'd brass now to start loading heavier charges, so am naturally curious to see what sort of velocity we'll be able to get before the limits a gas gun imposes step in. With these admittedly light charges, my perception in shooting the rifle off the bench is that recoil w/o a brake is very close to that of a similar rifle in 308, shooting max loads, but with a PRI brake.

I'm thinking th 7mm-08 AR30 would be a good cartridge to chamber a bolt gun in....

 

[Laurie]

Dennis,

7mm-08 AR30? An adaptation for gas-guns (hence AR)? and the '30' part from the shoulder angle? Haven't heard of that one before.

Oddly, you don't hear of Ackley type improved 7-08s either. With the popularity of the .260AI, the 7mm version should do just as well, you'd imagine.