Does anyone have any ballistic data on a Rem 700 16.5" 1/10 barrel, chambered in .308? If you have one and mounted a suppressor, even better. This is the direction I'm planning on going with my bolt gun. I'll mainly be shooting Federal GMM 168gr BTHP. The reality is that I probably won't be shooting past 600 but I'd like to know if anyone has.

10 rounds of Hornady 168gr TAP "Red Box" averaged 2524fps from the 16.5" 700 Tactical 308 I owned last year, and that velocity verified on steel at 900 yards using Litz G7 for the 168 A-Max.

Thanks! That looks like only about 120fps loss in velocity. That shouldn't affect medium range shots too much.

If you reload try some 175's for kicks and grins too. I know just out to 600 yards the 168's will be hard to beat but if it were me I'd try the 175's or 178's with that 1-10 twist.

I have a decent amount of data compiled for my rifle. See below:

PPU 308 Match 175gr
Group #1 = 2.21” Group #2 = 3.1”

Hornady 308 155gr TAP FPD
Group #1 = .9”Group #2 = .83”

Hornady 308 Win 168gr Z-max (Zombie Ammo)
Group #1 = .38” (Clear winner - see duplicate results from hand load below)

Remington Primer Match 308 Win 175gr Matchking BTHP
Group #1 = 1.9” Group #2 = .67”

Hand Loads – 175gr Sierra Matchking BTHP/42.5gr of H4895
Group #1 = 1.0”Group #2 = .85”Group #3 = 1.25”

I have had zero luck with 175gr projectiles. As you can see from the results above, factory ammo and handholds both result in MOA or larger groups. I have had great success with the 168gr A-Max bullets. My go to load is a 168gr A-Max, 45.5gr of Varget, and a Federal Gold Medal Match primer. With an average velocity of 2555fps it produces .5-.3MOA five round groups (Similar to the factory Z-Max/A-Max ammo). I have also done some loading with Hornady  168gr BTHP  projectiles and those were all around .75 MOA. The rifle seems to love the A-Max projectiles.

As an observation, the 16.5" barrel seems to be really picky when it comes to ammo. I found a load it likes and stuck with it, everything else seems to shoot just over 1 MOA (could just be my rifle though). My 308's with longer barrels are a lot more forgiving when it came to testing ammo.

I started off exclusively shooting the rifle with an AAC Sdn6, but took it off after I found that it was opening up the groups to around 1 MOA. Good can, just not meant for precision work in my opinion. If you are using a thread on suppressor or one with a solid mount, then you shouldn't have the same issue.

16.5" AAC-SD  suppressed vs. 20" AAC-SD


Hornady Z-Max

Thanks Recon! That's some good info. I'm going to be using my Saker 7.62 as a thread on suppressor. We'll see how it goes with regards to accuracy.

I've heard the 175 Sierra Match really loves that 1/10.

I'm considering a 16.5" or 20" AAC SD.  Do you think you're getting much unburned powder hitting your suppressor on the shorter barrel?

This is a pretty good article on testing. I'm comfortable with what I'm going to do with it. Some of the guys in here also have pretty good info with that barrel length.
http://rifleshooter.com/2013/11/super-short-precision-rifles-a-16-5-308-tactical-bolt-action-rifle/

This is exactly the kind of information I was looking for. Thanks so much for that link!

Not in my AAC. At all.

Did you get those numbers/groups with rifles you pictured?

If so.... I'd suggest a better stock.

I use 175 SMK's on my 18.5" 1-10 Schneider,  46.6 Of 2520, chrono'd at 2575.   Running a TBAC 30P-1. 3/4 moa as fast as i can put them out on my Dillon 550.
Very happy Them.
1.7mil at 300
2.7     at 400
3.7 at 500
6 at     600
7.7 at    700
9.3 at 800
11.4 at 900

All on steel
Hope this helps.

Apologies in advance, as this will be somewhat of a sidetrack, however I think that it relates directly to the 175 performance issues.

When you did your load workup for the 175 hand loads, did you try different seating depths and neck tensions?

One of the keys to great results is getting consistent neck tension on the bullet, and getting a very consistent release from the case each time. If you have inconsistent neck tension, it will impact how and when the bullet is released, which will change the performance from shot to shot.

When you move up in bullet weight, you also typically increase the bearing surface of the bullet (flat area in the middle), and this in turn increases the amount of bullet that is interacting with the case neck.

You may be seeing better results with the 168 loads because those bullet designs have less bearing surface and are getting a cleaner/more consistent release from the case.

If you are running the 175s at a factory COAL of around 2.800, then there is more of the bullet in the case, and more of the bearing surface is interacting with the case neck. To try and "work around this", you can lengthen the COAL which will put less bullet inside the case neck, or if you are using a bushing die you can run a larger bushing and decrease the neck tension slightly. Most precision shooters will run around .002" of neck tension, where factory ammo can be anywhere from .003"-.005".

You may also have a tight neck in your rifle's chamber, which will also have an impact on how consistent the bullet is getting released.

Most people want to focus on twist rates / bullet stability when it comes to performance issues, and while that could be a valid issue, many times it is not really the root cause of the problem. I this case a 175 bullet in a typical 1:10 barrel at 2,550 fps, has a stability factor of over 2.3 which means it is not anywhere close to being an issue (above 1.5 is good). Twist Rate / Stability

Obviously if the 168s are working for you and you are happy with them run with it. However if you haven't done it, make sure that you try some different things with your handloads using a heavier bullet before you completely give up on them.

Hopefully that all makes sense, if not let me know and I will try to clarify.

Best of Luck,
M Richardson

My 20" 1 in 10" AAC-SD loved the Hornady 168gr AMAX which I believe is the same load as the ZMAX.

Subscribing for when I get this thing up and goin.

I'm a newbie to all this and that was a very informative and helpful post. Thank you!