16" or 18" barrel

[kramaa]

I'm looking to use my 308 AR for hunting, does the differnce on barrels make too much difference.

[GLSHOOTER]

Jun 9, 2011 17:09:23 GMT -8 kramaa said:

I'm looking to use my 308 AR for hunting, does the differnce on barrels make too much difference.

It can be an issue if you want to reach out and touch something as the 16" is going to cut down velocity as compared to the 18 which, of course is less than a 20, 22 or 24 version. It will be a bit easier to take out in the woods though.

To give you an idea from my experience. Federal Gold Match 308 with a 168 grain BTHP bullet will run out between 2650 and 2700 out of a 24" barrel. When you cut that one back to 16" you are going to loose at least 200 FPS and quite possibly more making it around 2500. The 200 FPS difference on that round is that at 550 the fast 2700 will have as much speed and energy as the 2500 load at 400. Quite a difference in the numbers. Now at 400 yards even the slow 2500 FPS load will take a deer out without an issue and will take down an elk easily if you can put the bullet in the boiler room.

Real world practical from the hunting stand point is that you could go with the shorty knowing your range is affected somewhat and still be efficient. The blast/noise of the shot will also be greatly increased. My choice would be a 20" tube but YMMV.

Let s know what you pick.

Greg

[Master Yoda]

18 or 20

[greentick]

If you are hunting/stalking in thick woods the extra barrel length may not be necessary and you will definately appreciate the shorter barrel moving in the woods. If you reload you can tweak your load to minimize flash.

If you hunt wide open spaces, you may need that extra 200fps.

I want to say that on thefiringline.com someone did an experiment starting with a 26" barrel and went down an inch at a time, listing the velocity at muzzle and at distance. Might help you make a decision.

[jasonprox700]

I have an AP4 with the 16" barrel that I use for hunting. I don't do anything long range with it, maybe 500 yards at best, and that's on steel and paper. I really like how handy it is to carry with the short barrel. The loss of velocity isn't really a factor.

[rswarden]

Last year I carried an Armalite AR10 Super SASS on a mid Texas pig hunt. By the time the hunt was over, with its 20" barrel (12lbs before optics), I had renamed it the BIG Pig.

[Deleted]

Hi,
I would take several factors to take into account:

Weight
For long hunts, specially if you walk, keep it light. This is paramount to me. You are going to be better off with a 16" light/fluted barrel or an 18" light and/or fluted barrel profile. The effect of length on speed will make small difference for the purpose. Even for tactical work with a heavier barrel those lengths are very compact and practical.

Twist
Pick your bullet/bullets and don't over do it with the twist. 12 or 13 twist should be plenty unless you plan in shooting above 180grainers in which case you will need 11 or even 10 that is also needed for subsonic work. As you know overtwist has a price that you pay with a tad of speed or +pressure.

Keep it simple
Ace stocks, carbon fiber stock, light magazine/s, a light scope. - Every ounce counts. 7-8lbs would make a nice hunting and all around carbine.

Accuracy
Remember that whether the purpose of the upper/system is to hunt or surgical work all things being equal a shorter barrel is a more accurate barrel. So for hunting is a win-win situation anyway.

Terminal performance
Don't worry too much about the speed. A good 155grainer is going to take care of business. The terminal performance is not determined by the speed and energy alone. More times than not is also related to the terminal characteristics of the bullet and if that is suited for the game in question and the impact velocity can assure proper expansion or whatever terminal properties of the projectile. Choose the types of targets/game, range and bullet/s before you decide on the barrel and system you need.

Everything starts and ends with the bullet, hopefully a good one. The rests is just the means of delivering the mail.

Don't worry too much you can always have another upper!

These are some of my average spreads from 16", 18" and 20" for reference. Do not compare some factory loads with long 24" and 26" barrels as some might be loosing velocity due to the unneeded and unused length + they might not fit your goals and purpose anyway.

16" - 1:12 Knights/DPMS
Hornady TAP 155gr 2579
Black Hills BT 150gr 2632

18" - 1:11 Knights/DPMS
Federal Match 168gr 2623
Hornady TAP 155gr 2612
Black Hills BT 150gr 2656

20"- 1:11 Knights/DPMS
Federal Match 168gr 2656
Hornady TAP 155gr 2707
Black Hills BT 150gr 2744

20"- 1:10 REM-SPS-TAC-AAC
Federal Match 168gr 2649
Hornady TAP 155gr 2701
SMK 175gr reload 2610

Let me know if you need more info. I have spreads and info from most 308 win conventional/commercial or unconventional loads.
I hope this helps.

Thanks.

[GLSHOOTER]

Did anyone notice this fellow hasn't logged on since June 20? I guess he got what he needed quick and moved on!!

Greg

[Deleted]

You are right! LOL! I saw the thread at the top and failed to check the op's post date.
Anyway, someone might find that thread useful!
Thanks for the headsup.

[GLSHOOTER]

Never said it wasn't useful but there is a lot of band width absorbed on boards that isn't always current. I've seen some threads on other boards recently that were 4 YEARS OLD!! imagine that for a "timely" response.

Greg

[rswarden]

Yeh I didnt notice the age of the OP. But the info is still good to know. I plan on ordering a 16" BHW fluted barrel soon.

[Deleted]

Good choice! As soon as I get the one I ordered in 6mm I will get the 308 in 18" but I have not decided if fluted or light barrel with heat sink.
We'll see.

[vne]

I've got a fluted 18" bull barrel that I love on my Ar-10. Dead accurate and shaved a little weight off. Cant recommend it enough!

[inferno333]

I found all this info very helpful!

I eventually want to build a 308 for pig hunting.