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If you were building a .308.......

I would shoot the 200.20X bullet or the 175 VLD... I would go with a 1-10 twist. Heck a 1-9 might be a better choice. Better to go with a little too much spin than not enough. The more stable the bullet is the better it can go through the transonic zone and stay on a predictable course.
 
I would shoot the 200.20X bullet or the 175 VLD... I would go with a 1-10 twist. Heck a 1-9 might be a better choice. Better to go with a little too much spin than not enough. The more stable the bullet is the better it can go through the transonic zone and stay on a predictable course.
In my mind, common sense tells me more spin on a heavier bullet is better, it seems 1-10 is the popular vote but I was wondering about something a little tighter.
 
I have many rifles based on a 308 case to include 2 6.5x47s. I’m just interested in building the most effective and efficient .308 I can.
Well the most effective depends on what you will use it for..is it for f/tr,bench rest or you planning on prs type stuff..If I was you I would get a nice repeater action like a bat vr or Tuebor Ti and spin up a barrel to single load and one to use as a repeater and be happy.
 
Well the most effective depends on what you will use it for..is it for f/tr,bench rest or you planning on prs type stuff..If I was you I would get a nice repeater action like a bat vr or Tuebor Ti and spin up a barrel to single load and one to use as a repeater and be happy.
I already have the build setup. It’s a deviant action, McMillan A5 stock, Timney Calvin elite, Krieger barrel, etc...I’m just trying to figure out what barrel length, twist, contour to go with to try to squeeze the most out of it.
 
First thing I’d do is ditch the McMillan stock and get a Manners..then 1:11 twist and run the 175smks or 155 scenars and be happy and maybe run a 28” hv barrel
 
Since some pretty important info has come out since the first post (i.e. repeater), perhaps you could state in detail what type shooting you intend to do with this rifle. Based on the repeater update, I would go with something like a 26-28" barrel, again, in whatever contour suits you weight-wise. Personally, I'd go with at least an M24, maybe MTU or HV, in 11-twist. However, not if I planned to be carrying the rifle around through the woods much. In that event, maybe a Med Palm contour, or even a Sendero would be much lighter. For bullets, since you're loading to mag length I'd suggest Berger's 175 OTM Tactical bullet. I shot this bullet loaded in Applied Ballistics commercial ammunition for a couple years in F-TR at 1000 yd, out of both 24" and 26" barrels. The 175 OTM Tactical is certainly not ballistically comparable to single feeding a 200-20X bullet out of a 30" pipe, but it has about an 8% better BC than a 175 SMK, and is very forgiving with regard to seating depth (tangent ogive). The rifles I was using had .085" freebore, which was just about perfect for that bullet, or just about any other lead core bullet up to 175 gr.

With such a setup, you could certainly also load something like a 185 Juggernaut if you chose to do so, but loaded to mag length, they'd be seated pretty far down in the case neck. That will limit the amount of "boiler room" you have to such an extent the 185s may be pretty slow, enough so that you might effectively lose the slight BC advantage they have over the 175 OTMs.
 
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Since some pretty important info has come out since the first post (i.e. repeater), perhaps you could state in detail what type shooting you intend to do with this rifle. Based on the repeater update, I would go with something like a 26-28" barrel, again, in whatever contour suits you weight-wise. Personally, I'd go with at least an M24, maybe MTU or HV. However, not if I planned to be carrying the rifle around through the woods much. In that event, maybe a Med Palm, or even a Sendero would be much lighter. For bullets, since you're loading to mag length I'd suggest Berger's 175 OTM Tactical bullet. I shot this bullet loaded in Applied Ballistics commercial ammunition for a couple years in F-TR at 1000 yd, out of both 24" and 26" barrels. The 175 OTM Tactical is certainly not ballistically comparable to single feeding a 200-20X bullet out of a 30" pipe, but it has about an 8% better BC than an 175 SMK, and is very forgiving with regard to seating depth (tangent ogive). The rifles I was using had .085" freebore, which was just about perfect for that bullet, or just about any other lead core bullet up to 175 gr.
Great info! Thanks. Yeah, I guess I should have been alittle more specific. The build
Is as follows.

-Defiance Deviant
-McMillan A5 (maybe my manners)
-Badger M5 bottom metal
-Timney Calvin Elite
-Nightforce ATACR 5-25 FFP
-Kreiger Barrel in a heavier contour

This rifle won’t make it into the woods. It’ll be my “pretty .308” that I shoot off a bench or proned out. It may take a deer or coyotes life at some point but that’ll be from the porch or a driven too point on the farm.
 
Great info! Thanks. Yeah, I guess I should have been alittle more specific. The build
Is as follows.

-Defiance Deviant
-McMillan A5 (maybe my manners)
-Badger M5 bottom metal
-Timney Calvin Elite
-Nightforce ATACR 5-25 FFP
-Kreiger Barrel in a heavier contour

This rifle won’t make it into the woods. It’ll be my “pretty .308” that I shoot off a bench or proned out. It may take a deer or coyotes life at some point but that’ll be from the porch or a driven too point on the farm.

In that event, why does it have to be a "repeater" 100% of the time? I have a couple .308 F-TR rifles that I mentioned above that were spec'd out and built before I had any idea what I was doing. They are both GAP rifles, with Defiance Templar actions (George's version of the Deviant), McMillan A5s, and Badger M5 DBM...very similar to your setups. With 30" 11-twist MTU barrels and the .085" freebore, I can easily load 185 Juggernauts with extremely good precision out of these rifles. I actually single feed the loaded rounds right on top of either AICS or Magpul mags, close the bolt and send them. No issues whatsoever, and you might be surprised how quickly you can send single fed rounds downrange with a little practice.

One of these rifles also shoots FGMM175 commercial ammo extremely well. I often practice with it at 300-600 yd when I don't feel like using up competition brass/bullets/powder/etc. When I do, they feed out of the mag perfectly. In other words, the right setup will allow you to do both. However with .085" freebore, you'd still be limited to relatively short bullets like the 175 OTMs for mag length ammo. If you set it up to single feed much longer (heavier) and higher BC bullets with a faster twist barrel and longer freebore(>~.150"), then your mag length loads will be jumping a country mile. With the right bullet that might also work just fine, but is probably not the route I'd choose to start. You could easily set that rifle up with ~.085" freebore, use it mostly with mag-length loads, but could also single-feed 185s once in a while if you felt like it. As you're not going to be carrying it around in the woods much, I'd probably go 28" and call it a day. Alternatively, 26" would also work, but you probably don't need a 30" pipe.
 
Most things covered ?
Chamber ??? I just finished a FT/R .308
I went with a Full Bore Reamer ? Not good to shoot 185 Berger’s .. think about the Bullets you want to shoot ? Get the right Reamer .
I went back and used a throatier to get the job done .
 

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