Need Recommendations For An AR Platform .308/7.62 Rifle

[ColoradoMinuteMan]

I never really understood the logic of a full power cartridge like the 308 with a 16" barrel ... doesn't it loose a lot of power with such a 16" barrel?

i did quite a bit research into that before picking a barrel for my M5E1. Most of them show a roughly 10% muzzle velocity loss going from a 26" to a 16" with most cartridges. Powders burn at different rates and projectiles accelerate at different rates so those two variables will be factors.

 

[Freedom_fighter_in_IL]

Quote:
I never really understood the logic of a full power cartridge like the 308 with a 16" barrel ... doesn't it loose a lot of power with such a 16" barrel?
i did quite a bit research into that before picking a barrel for my M5E1. Most of them show a roughly 10% muzzle velocity loss going from a 26" to a 16" with most cartridges. Powders burn at different rates and projectiles accelerate at different rates so those two variables will be factors.

Not to mention different rifling types and depth as well as the "slickness" of a barrel. Also, 99% of powders are burned by 9 inches in MOST 30 caliber barrels. Your smaller caliber barrels with larger cases (over-bored) tend to have more issues with unburnt powder in short barrels (not to mention gas cutting on the throat), take the .25-06 for example. That bugger can be murderous on a chamber throat.

 

[ColoradoMinuteMan]

Not to mention different rifling types and depth as well as the "slickness" of a barrel. Also, 99% of powders are burned by 9 inches in MOST 30 caliber barrels. Your smaller caliber barrels with larger cases (over-bored) tend to have more issues with unburnt powder in short barrels (not to mention gas cutting on the throat), take the .25-06 for example. That bugger can be murderous on a chamber throat.

Absolutely, there are a lot of factors, many of which are difficult to measure. Through my research it seems that on "average" the .308 will burn 95% of it's powder in the first 8" of travel. The rear of projectile is already about 1.5" down the barrel when loaded in chamber so that is 95% powder burn at 9.5" down the barrel. Full powder burn will occur when the rear of the projectile is at about 24". Although, 95% of the power is burned at 9.5 inches the projectile will accelerate nearly 30% more between 9.5" and 24" inches equating to roughly 600 FPS gain between 9.5" and 24". Even though all powder is burned at 24" the projectile will continue to accelerate, albeit not much past 28".

 

[CANNONMAN]

Dear JF, Suggest you give reloading this gun your in the hunt for a try. Tons of awesome advice here and supplies for this gun are all over. Super cheep on e-bay. 60y/o and just learning bottle necks. Something about starting from scratch. Same goes for biscuits. I can't tell you how much so much of the guys here have helped me along. For what it's worth, a 16" barrel will give you the accuracy you've stated your looking for, and substantially better. Hope you post a range report of your new gun, self made ammo and a target.

 

[yzguy87]

I have experience with DPMS and Rock River. Had a DPMS lr308 w/ a 24" stainless barrel and an ap4. I sold the 24" stainless upper and bought a tac-20 upper. They were good guns. Honestly, I never grouped them. They always hit my targets though. Later I got rid of them and bought a RRA standard 20" but the previous owner installed a free float tube. Wow, that thing was accurate! 1st range session out with it after sighting it in I put 5 rounds inside a quarter at 100 yds. with 145 gr. ball ammo. That was amazing! I was so happy with my purchase after that day!

I must add that I did not sell my DPMS guns for the RRA. Several years ago I had more discretionary income and I used to buy guns more frequently.

 

[dr0]

"I like my Colt".

Does Colt make .308 caliber AR's. Last I saw they only had the .223/5.56 caliber.

 

[Fullretard]

LMT MWS in 308 street price is 2500-2800 as used

I love mine
buy once cry once