When To Choose A .308 Over 5.56?

[Nightvisionary]

Sorry to take this slightly off the original topic, but I was under the impression that .300BLK offers better terminal ballistics when compared to a comparable length 5.56 SBR (e.g. 10.5"). Am I off base, or that an oversimplification? I'm considering an LMT MRP as my first SBR and though the idea of having 10.5" barrels in both 5.56 and .300BLK sounded appealing.

While I certainly appreciate the characteristics of 7.62, I guess I'm just not ready to commit to a whole new platform, magazines, etc.

Dave

I would say that is a major oversimplification. With the exception of two limited production Barnes bullets a 300 Blackout with a 9-12 inch barrel will be at or near the minimum expansion velocity at the muzzle for every .308 bullet currently in production.

[bzdog]

I would say that is a major oversimplification. With the exception of two limited production Barnes bullets a 300 Blackout with a 9-12 inch barrel will be at or near the minimum expansion velocity at the muzzle for every .308 bullet currently in production.

I'm not sure saying 300 BLK doesn't perform optimally with bullets not designed for it should be considered an issue.

For defense inside of 100 yards 300 BLK with the 110gr Barnes black tip is going to be hard to beat, even out of a very SBR. Make that 200 yards for a 16". With these combinations, the bullet is traveling fast enough for a rifle wound profile and you get reliable expansion and s barrier blind full copper bullet. I'd call this combo for this application cake and eating it too.

After that it gets a bit more gray as the 300 BLK slows down and drops faster. That said, the Barnes black tip reliably expands to 1300 FPS which ends up around 400 yards out of a 16".

And as for availability, the Barnes black tip has been pretty much the only premium ammo that was available through the BLK ammo shortage.

-john

[C-grunt]

I prefer 5.56 as my general purpose carbine. Low reoil, lots of ammo and pretty flat shooting out to 400 yards or so. The 308 I use as a support and precision round. My only 308s have always been precision bolt guns. Though there is a very good argument on using the 308 as a general purpose gun as well. To me the 300 BLK has finally legitimized the PDW concept (excluding the KAC thats not available). Up until now the PDWs have all been lacking in the terminal performance department especially at range. An eight inch 300 BLK has great close end terminal performance but still has some legs under it if the gunfight moves out to a couple hundred yards.

My personal setups (If I could afford all of them)

300 BLK. 8 inch barrel topped with a good red dot 0-250 yards

5.56. 11.5-16 inch barrel topped with a good red dot or low powered optic 0-400 yards

308. 16-24 inch barrel topped with a good low or high powered optic depending on the mission/terrain. 0-1000 yards

[bzdog]

308. 16-24 inch barrel topped with a good low or high powered optic depending on the mission/terrain. 0-1000 yards

While I don't disagree, why .308 over 300 Win Mag or such?

-john

[C-grunt]

While I don't disagree, why .308 over 300 Win Mag or such?

-john

I like 308 for its general ubiquity. Though for a dedicated precision rifle I do believe that there are many better offerings than the 308.

Plus the original post was about the 308.

[bzdog]

To me the 300 BLK has finally legitimized the PDW concept (excluding the KAC thats not available). Up until now the PDWs have all been lacking in the terminal performance department especially at range. An eight inch 300 BLK has great close end terminal performance but still has some legs under it if the gunfight moves out to a couple hundred yards.

Over all a good characterization about the performance of the SBR 300 BLK when using good defensive ammunition IMO.

-john