Long Range 308 bullet

[Quaz]

Just got a new to me FN Scout rifle. It is basically a Winchester model 70 controlled feed I think. Put a Zeiss Z3 6-36X56 scope on it with Zeiss rings. I'm hoping to get this rifle driving targets to 800 yards and above off the bench. Currently I'm shooting Nosler 168 gr and Federal Gold Sierra Match 168gr ammo. Question is what grain bullets do these guns like. It has a 24" barrel with 1:12" twist. I live in the east so most of my deer have been shot sub 200 yards in the thick Appalachian mountains and farmland.

 

[bruceleroy]

I would pick the Hornady ELD-M as their BC is much higher than the 2 mentioned. Regardless of that, pushing them out of that barrel will likely be fine. Do you know what speeds you are getting now?
I shoot the ELD-M out to 1200 out of a 16 inch barrel but at 6k ft.

 

[Quaz]

According to the box not chronograph 2750FPS at muzzle 1701FPS at 600. Not sure how accurate that is.

 

[Dos XX]

A 12 twist should work with up to 185 gr bullets, for sure. Might be OK with heavier even. But I have shot several thousand 185 Berger OTM matches out of a 12 twist.

 

[djauofd]

Well a 1x12 Twist barrel is going to limit you. A stability factor of anything less than 1.4 gets to be questionable. So let’s say you get 2,600 fps out of a 180 grain bullet. The problem is that as you seek higher BC bullets the get longer. As the length of the bullet increases the higher the spin rate to keep it stable. New bullets that attempt to increase bullets BC by making the bullet longer and more aerodynamic change stability greatly.

For example a 165 SST at 2750 has a stability factor SD of 1.5 in a 1x12 . So it’s very stable. It has a G7 of . 224. Go to a 168gr Nosler AccuBond Long Range and the G7 goes up to .298 but your stability factor changes to 1.18. This is not good and the bullet will be very unstable.

The 168 Nosler ABLR is 1.39” long , the 165 SST is 1.274” long.

So say you look at a Berger 180 Elite Hunter. It is 1.376” long and it has a G7 BC of .295. At 2,630 fps is has a SD of 1.30 . So again will it be stable or not? Questionable.

So for the ranges you are hunting at 165 to 178 class bullets will work except you are using long slender high BC bullets for their weight . Like the 168 Nosler AccuBond Long Range.


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[MarlinsDad]

Try the Hornady eldm in 168gr, they are the “updated” a-max work like a champ for us. I used a 308 exclusively for a few years culling whitetail for local farmers, inside 200 stay off the shoulder I used a heavy barrel and normally ear holed them, anything past that I shot high shoulder very rarely did I have a runner.