So I've chosen to stick with 308Win as the caliber for my new barrel, but I don't know what I need for the freebore.

I plan on shooting 175 and 200 SMK (sku 2231), goal is 1000-1500 yards. As availability returns and prices go back down (hah) I will open that up to the Berger 200.20X I've heard so much about.

I was honestly thinking about just going with 0.200" and calling it a day, but I've dumped enough money into this build that I want it to shine.

If ultimately you're going to shoot the Berger 200.20X, have your chamber throated for those. Buy a box or call Berger and have a few sent to you, tell them what you're doing. Load a couple dummy rounds with where you want the bullet in the case. Send those dummy rounds to your gunsmith and have the chamber throated to that round. Give the gunsmith the bullet jump/jam you want as well.

I've had the above done with a few different calibers. Not uncommon for gunsmiths to order reamers with short freebores and throat all chambers. Good gunsmith will get the throat within a thou. One gunsmith asked me to load the bullet OAL including the jump I wanted.


1500yds with a 308? Seriously?

A man can dream, right?

Okay, I might have been a tad ambitious there. I keep forgetting its practical limitations.

Curious to know where you'll find 1200-1500 yds in the Memphis area??

Good Luck
Andrew

A family friend has a 1200 yard (currently) range set up on their farmland in Byhalia.

It's where we practice with the 6.5's.

I was ringing steel @ 1240yds with my 6.5 Cm Sunday at a local range. Using 140 Bergers, its big fun once you get your load right.

quote:

Originally posted by offgrid:
If ultimately you're going to shoot the Berger 200.20X, have your chamber throated for those.

1500yds with a 308? Seriously?

+1 to offgrid's comments. Especially at distance, with what he ribs me as the "3-oh-hate".
I have no experience with the 200 SMK, but the 175 SMK seems to tolerate various throats. Cut the chamber for what you will eventually shoot.

Now for a little 6.5 Creedmoor vs 308 at 1200 yards. I've shot both at this distance. The 6.5CM is hard enough, but the 308 can be an exercise in frustration, especially with wind issues. My assumptions are:
- JBM ballistics for the data
- target is a 24" square plate at 1200 yards - essentially 2 MOA
- 5000 feet Density Altitude - yes, this is thinner air than you (OP) will likely see at home. Heavier air than I see.
- 6.5CM MV of 2820 fps with Hornady 140 ELD - what I obtain from factory ammo. Normal batch.
- 308 MV of 2760 fps with Hornady 168 Amax - what I obtain from factory ammo, and this is somewhat of a hot batch.
Now I realize you're looking for better bullets for the 308, but at lower MV. Run the numbers, as the 200s might be only a tad better than my Amax numbers.

6.5CM needs 35.4 MOA of elevation. 10mph wind drift is 6.9 MOA. Terminal velocity is Mach 1.32.

If my rangefinder is acting up, I'll still be on target if the distance is 1180-1220 yards. Meaning a 40 yard margin for error.

If the muzzle velocity of my load varies, I'll still be on target if the MV is 2785-2850. Meaning a 65 fps margin for variation.

I must estimate wind speed within 2.9 mph to hit the target. Not a very big margin for error.

Velocity of Mach 1.32 means the bullet is still flying pretty well, as it's above transonic. Barely. Other calibers do better at this distance.
****

308 needs 45.2 MOA of elevation. 10mph wind drift is 10.5 MOA. Terminal velocity is Mach 1.00.

If my rangefinder is acting up, I'll still be on target if the distance is 1187-1214 yards. Meaning a 27 yard margin for error.

If the muzzle velocity of my load varies, you'll still be on target if the MV is 2735-2785. Meaning a 50 fps margin for variation.

I must estimate wind speed within 1.9 mph to hit the target. An even smaller margin for error.

Velocity of Mach 1.00 means the bullet could get seriously wonky at any time. Probably already wobbling. I know Amax is still flying nose first at this distance at 9,000' DA with my rifle, but I won't make the call for other situations.

Yeah, a 308 bullet will go 1200 yards. Even farther. But it's not the best tool for the job.

1500 yards with a .308? Look up the concept of volley fire.

Fritz, Kudos to you for breaking down a target to elevation size (velocity spread) and windage size (margin of wind call). Many shooters don’t take the time to know what their parameters for wind call error and extreme spread are in relation to their chosen target size. It’s information worth knowing.

(I actually meant to post this last night and fell asleep instead.) I admit, I got overzealous in thinking about distance. I'm probably going to spend most of my time at 750-1000. If I were to compete around here, everything's at 600 until you get to like St Louis, and for that my 6.5 is way better in almost all aspects than 308. Something, something, something, recoil. Still, that's not going to stop me from taking the 308 out as far as I can. I figure it'll last me a while, then I'll get bored and sell off the barrel then rebarrel it for whatever the Nucleus ends up in, as a trainer rifle like I originally planned.

fritz and offgrid, thank you for the information.