AR-308 – 308 Winchester Cartridge Overview

The 308 Winchester cartridge is one of the most popular, flexible, and accurate rifle cartridges in existence. Whether it be for big game hunting, military sniping, competition shooting, or just having fun, the 308 Winchester is well suited and very capable for these applications. The fact that this cartridge is so popular means that brass is readily available, as are bullets and reloading equipment. For long-range shooting, this cartridge is a great choice, and the fact that the AR platform was originally designed around this cartridge (AR-10) is one of the reasons I wanted to take on this project!

The 308 Winchester is similar to the 30-06 Springfield cartridge, but there is one key difference- the 30-06 is for long-action bolt action rifles, where the 308 Winchester is a short-action cartridge. The 308 Winchester is less powerful, but is in the same ballpark in terms of ballistics and performance for big-game hunting. For competition shooting, they perform very similarly, but competition shooters have pretty much migrated to the 308 Winchester cartridge when given the choice between the two. (that’s a whole different subject).

What’s interesting about the cartridge dimensions is that the case rim is similar enough to other popular rifle/pistol cartridges that you can actually use the same shellplate/shellholder for 308 Winchester, 30-06 Springfield, 45 ACP, and many other cartridges in most cases.

Here’s what Hornady lists for their #1 shellplate for the Lock-N-Load AP: (note that the #45 shellplate was fine tuned for 45 ACP)


  • 5.6x57mm
  • 22-250 Rem
  • 22-250 Rem Ackley Imp 40°
  • 240 Wby Mag
  • 243 Win
  • 6mm International
  • 6mm-284
  • 3mm Rem BR
  • 250 Savage
  • 25-06 Rem
  • 257 Roberts
  • 25-284 Win
  • 260 Rem
  • 6.5 Rem Mag
  • 6.5mm-06 A-Square
  • 6.5x57mm Mauser
  • 6.5mm-284 Norma
  • 6.5 Creedmoor
  • 270 Win
  • 7x57mm Mauser
  • 7mm-08 Rem
  • 7mm Rem BR
  • 7x64mm Brenneke
  • 280 Rem Ackly Imp 40°
  • 284 Win
  • 300 Savage
  • 308 Win
  • 30-06 Spfld
  • 30 TC
  • 338 Federal
  • 7.7mm Japanese
  • 7.92x33mm Kurz Mauser
  • 8x57mm Mauser
  • 8mm-06 Spfld
  • 338-06 Spfld
  • 35 Whelen
  • 358 Win
  • 9.3x57mm Mauser
  • 9.3x62mm Mauser
  • 400 Cor-Bon
  • 44 Auto Mag
  • 458 Socom
  • 450 Bushmaster

Pretty impressive interoperability! This means that you can buy one shellplate, and use it for many different cartridges for reloading without having to swap out the shellplate and priming system (something to think about when considering how to equip your gun safe).

Let’s take a look at the dimensions and specifics for the 308 Winchester cartridge:

308 Winchester Cartridge Specifications - Image by Francis Finch

OK, looking at a chart is one thing. Let’s now line up some popular rifle cartridges from the mighty 50 BMG down to the thrifty but prolific 22 Long Rifle. This will give you a better idea of just how the 308 Winchester compares to other rifle cartridges from a more “qualitative” perspective.

Comparison of popular rifle cartridges, from left: 50 BMG, 30-06 Springfield, 308 Winchester (center), .223 Remington, 22 Long Rifle - Image Copyright 2011 Ultimate Reloader

I’ll have to say, I really like the 308 Winchester cartridge. Since it uses .308″ diameter bullets that means I can find exactly what I want in terms of weight, profile, quality, and I also know I’ll get a good price. I like the fact that I can use the same rifle to shoot from the bench, and to also hunt deer with. What’s not to like about 308 Winchester? I’m not sure…

It’s also worth noting here that the military has adopted the 308 Winchester cartridge (7.62×51) – and the dimensions are not exactly the same. The good news is that SAAMI has designated the two cartridges as “interoperable”. So unlike the .223 Remington -vs- 5.56 NATO issue (not compatible), you don’t need to have the same worries with 308 Winchester and 7.62×51 brass/ammunition. What you do need to do is keep your brass sorted so that you can prep each to spec, and ensure consistency/accuracy.

There’s plenty more we could talk about here, but we need to move on so that we can get to loading! 🙂


One thought on “AR-308 – 308 Winchester Cartridge Overview”

  1. Wondering how much or should you taper crimp a well prepared case for an accurate bullet for a semi-auto platform? I am also wondering if you need to use a bench rest primer in a semi-auto. I am following this AR-10 project closely.

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