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16" versus 18"

4412 Views 20 Replies 18 Participants Last post by  alexrex20
Okay guys - I am in the process of building another 6.8 SPC as a dedicated deer stand gun. Long story short, last year I built an AR10 for deer hunting and once it was completed, I realized it was just going to be too heavy to carry comfortably through the woods while on drives. Accordingly, I built a lightweight 6.8 (Thanks to the help of this forum) with a WC 16" lightweight profile barrel as my "woods pushing gun." I took two bucks last fall with the 6.8 and I liked the performance so much that I want to replace the AR10 in the deer stand with another 6.8 with greater magnification on my optic (My current 6.8 has a 1-4).

My questions is what are everyone's thoughts on the benefits of going from a 16" barrel to an 18" barrel? In northern MN and WI my longest shots in the woods are maybe 200 yards but occasionally I sit on a cornfield, where shots can be longer. I really like the short feel of the 16" and the weight but I am wondering if going the ballistic benefits of going to an 18" would be worth it. Thanks in advance.
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Okay guys - I am in the process of building another 6.8 SPC as a dedicated deer stand gun. Long story short, last year I built an AR10 for deer hunting and once it was completed, I realized it was just going to be too heavy to carry comfortably through the woods while on drives. Accordingly, I built a lightweight 6.8 (Thanks to the help of this forum) with a WC 16" lightweight profile barrel as my "woods pushing gun." I took two bucks last fall with the 6.8 and I liked the performance so much that I want to replace the AR10 in the deer stand with another 6.8 with greater magnification on my optic (My current 6.8 has a 1-4).

My questions is what are everyone's thoughts on the benefits of going from a 16" barrel to an 18" barrel? In northern MN and WI my longest shots in the woods are maybe 200 yards but occasionally I sit on a cornfield, where shots can be longer. I really like the short feel of the 16" and the weight but I am wondering if going the ballistic benefits of going to an 18" would be worth it. Thanks in advance.
Go with an ARP 16" barrel. The melonite barrels in 16" will shoot as fast or better than an 18" stainless. With the right bullet and proper shot placement the deer won't know the difference.
Do you handload? If so, then you may appreciate the extra velocity you can squeeze out of the 18". But if you are mainly concerned about ~200 yards, then 16" should be fine. If you are thinking you might go out to 300, then again, you might appreciate the small gains from the 18".
I have a 12.5", a 16" and 2 - 18" 6.8ARP barrels. All shoot better than I can but the 18"s shoot like a laser beam. Put you a 4-12X scope on a 18" and you have yourself a 'deer drill'. Perfect for a stand hunting rig provided you have a shooting rest IMHO.
i've got the 12.5", 16", 2-18", and a 20". likely going to pull the 20 and build another 16 when the socom barrels are in stock at ARP. between 303's results from a 16" and my results from an 18" the 18 is around 50 FPS faster, that's using the CFE BLK results
I prefer the 18" over any length. Not as loud or bad on the ears when hunting and I really don't notice the extra 2" or weight.
I don't like long hand guards or short ones.

I just built a 18 ARP 6.8 and have a black hole 18" 6x6.8! I couldn't be happier.

Sent from my Tank Xtreme 5.0 using Tapatalk
You may gain 40-50fps by going from a 16" to an 18" of the same make.
You may gain 40-50fps by going from a 16" to an 18" of the same make.
That's why I've not went passed 16". With 2 -12.5" APR SBR's and my 16" ARP, they do all I need for deer hunting.

With a supply of 90 gold dots and some Cavity Back Bullets, that's all I need.
I've got a 18" ARP target crown and a 16" Scout. With muzzle device on the 16" length is close.
My difference is 72 fps between the two.

I feel that is worth the extra barrel length as my 18" is a Stand Gun and the 16" is a stalker.

Now, that said, them swine can't tell the difference.
Maybe I'm missing something, but why not just get a second optic for your current 6.8? With modern mounts, scopes will usually retain zero after removing and reinstalling them.
I have got both a 16" ARP and a 18" ARP and a 18" X-caliber barrel. I prefer the 18's myself. They just seem to balance better for me.
Maybe I'm missing something, but why not just get a second optic for your current 6.8? With modern mounts, scopes will usually retain zero after removing and reinstalling them.
This is just my excuse to build another rifle - can never have to many!
Thanks for the input, everybody. I do not hand load at the moment, which is why I was pondering 16" vs 18" but at only 50-100 FPS faster, I may just roll with a 16". Now, to look into the ARP barrels.
I bought a lightweight stainless steel 18" barrel primarily because it was on clearance . . . I did a little research, and then couldn't help but pounce on it at that price. Since then, I've agonized over the matter of 16" vs. 18", and finally decided to do some window shopping, calculator in hand. It turned out I only would've saved about 3 ounces by going with my favorite 16" barrel (which also would've cost $120 more).

So I guess what I'm suggesting is that you look at the exact weights and let that guide you. They vary.
Go with an ARP 16" barrel. The melonite barrels in 16" will shoot as fast or better than an 18" stainless. With the right bullet and proper shot placement the deer won't know the difference.
+1, I've owned both and still own the 16" ARP.
I had the 16" briefly. I pretty much stand hunt. I have the 20" and 24" rifles. I use the 24" exclusively for deer stand hunting.
Thanks for the input, everybody. I do not hand load at the moment, which is why I was pondering 16" vs 18" but at only 50-100 FPS faster, I may just roll with a 16". Now, to look into the ARP barrels.
Some factory offerings are a little anemic as to fps. A longer barrel might be worth the effort to gain 50 or more fps.
My results

I recently replaced my Rock River Arms 16" heavy barrel (1:10 twist) with an 18" ARP barrel with 1:11.25 twist, 5R rifling, and melonite coating.
Here are the results from two different Federal factory loads. (90 grain gold dot and 115 grain MSR)
I saw a muzzle velocity increase of 106 - 190 fps.

click pic to expand.
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I've shot a lot of 6.8 over the years (10.5", 14", 16", 18" and 20"). I currently own an 18" and 20". 18" just seems to be optimal IMO.
I have had 2 ARP barrels in 16 one of which needs a new home decided 12.5 mid length would suit my needs better on my hunting rig all 3 have shot lights out
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