how long should the barrel be????

[Muley]

Thinking about buying another ar. I don't know whether to get the 20in. barrel with a 1-8 twist, or the 24in. barrel with a 1-9. I know I will be shooting 60 to 70 gr A-max. I just don't know if I want to loose speed with shorter barrel. Anybody who knows how much velocity you loose per inch with shorter barrels, lets talk.......

 

[patsygarret]

i think the only weight in .224 is 75 grains for the amax and i know most guys running the a max are in the 1-8 or 1-7 twist. i would stick with the 1-8 and let the higher b.c do the work.

 

[snakeman]

i agree with patsy

 

[sprice]

I would go with the 20'' 1/8 twist.

 

[Z-Michigan]

What is your goal for this gun? Targets, competition, varmints? What distances?

You would probably lose 60-80fps going from a 24" to a 20" with the bullet weights listed. At 1000 yards, or even 600, that would make a difference. At 100 yards, not so much.

 

[Muley]

mostly coyotes under 500. I have a .308 nail driver that I like to reach out and say hello with.

 

[orvpark]

18-20" 1:8, any longer in a AR is overkill.

At least under 20 it can serve other purposes as well.

 

[rcmodel]

Food for thought!
It might be worth noting that the M16 Mark 12 Mod 0/1 Special Purpose Rifle (SPR) used by Army & Marine snipers, and Squad Designated Marksmen in Iraq has an 18" barrel.

The effective range is listed as 600 yards, but you don't one of those guys shooting at you at 700, 800, or 900 I betcha!

http://en.wikipedia.org/wiki/United_States_Navy_Mark_12_Mod_X_Special_Purpose_Rifle

rc

 

[Uncle Mike]

24" 1:8" with those bullets.

 

[dubbleA]

Just a reminder, the 75gr Amax is a single load proposition in the AR. My 1:8 will shoot them very well.