Berger 155 vs 175 or 185 for .308

[Mr_Happyface]

I have 26" 1:12 barrel .308, currently shooting Berger 155.5s at 3000fps with 47.5 grains of 8208.

I believe 28.5 MOA to 1K. It works well and I'm happy with it, but because I like to tinker with things that don't need it I've been thinking about switching to something heavier, wind is KILLING me past 1k!

So if I understand this correctly heavier bullets will have more drop, but less susceptibility to wind, correct?

Been reading about the Berger 185 juggernauts, does a .308 have enough juice to make it worthwhile, or should I look at 175s?

Also, I have a ton of 8208, I'm guessing it burns too fast for that weight bullet correct?

 

[Graham]

Berger 155 vs 175 or 185 for .308

You mean that you are presently shooting beyond 1000 yards with 155 Bergers in a .308, and you don't understand BC or have data for the powder that you are using?

 

[FCS]

JBM ballistics web site is your friend.
JBM - Calculations - Trajectory

185 Juggernaut @ 2750 will drift less then the 155.5s @ 3000. Depending on chamber dimensions, shouldn't have too much trouble getting 2750 from the 185s via 26" bbl.

8208 is too fast in burn rate, need something more in Varget, RL-15, IMR4064 or 4320, N-140 or N-150 burn rate range.

185 has G7 BC of .283
155.5 has G7 BC of .237

Gain 19ish % in BC, lose about 8% in velocity....gains you a fair bit in drift #s at distance.

Did I mention that JBM ballistics would be a good site for you to spend some time at?

 

[Mr_Happyface]

Graham, thank you for the helpful response.

FCS, thanks for the info, I used JBM to work up the info I'm using currently. It's incredibly accurate. Where I was hitting a block in the whole idea was finding what kind of velocity I could expect out of a 26" with 185s so that clears things up.

The difference in BC between the two is what made me start to think about switching, I was just concerned I wouldn't be able to push them fast enough.

Gotta' research these powders now, all I've ever used is 8208.

 

[M14 Shooter]

Just a heads up.45.3 is the max load listed for 155 Grain Bullet in 308 for IMR 8208.I was using 45 grains with Laupa brass and was starting to have pressure issues.(hard lifting bolt).

Regards,Mike

 

[Mr_Happyface]

Just a heads up.45.3 is the max load listed for 155 Grain Bullet in 308 for IMR 8208.I was using 45 grains with Laupa brass and was starting to have pressure issues.(hard lifting bolt).

Regards,Mike

Believe it or not I have no pressure signs at all.

I'm barely seating them in the case; (my OAL is 2.945") that combined with flash hole deburring might be buying me some case capacity to play with.

 

[Graham]

Graham, thank you for the helpful response.

You're so right: I didn't answer your questions.

1) No.
2) Maybe.
3) It depends.

 

[glock63]

Graham, thank you for the helpful response.

FCS, thanks for the info, I used JBM to work up the info I'm using currently. It's incredibly accurate. Where I was hitting a block in the whole idea was finding what kind of velocity I could expect out of a 26" with 185s so that clears things up.

The difference in BC between the two is what made me start to think about switching, I was just concerned I wouldn't be able to push them fast enough.

Gotta' research these powders now, all I've ever used is 8208.

Check out RL17. I haven't had a chance to complete my load development with it and the 185 juggernauts but it looks promising. Seems to be a good powder for pushing heavier than standard bullets to higher velocities without pressure signs.

 

[Steve Williams]

JBM ballistics web site is your friend.
JBM - Calculations - Trajectory

185 Juggernaut @ 2750 will drift less then the 155.5s @ 3000. Depending on chamber dimensions, shouldn't have too much trouble getting 2750 from the 185s via 26" bbl.

8208 is too fast in burn rate, need something more in Varget, RL-15, IMR4064 or 4320, N-140 or N-150 burn rate range.

185 has G7 BC of .283
155.5 has G7 BC of .237

Gain 19ish % in BC, lose about 8% in velocity....gains you a fair bit in drift #s at distance.

Did I mention that JBM ballistics would be a good site for you to spend some time at?

JBM is a very useful tool, the G7 value of your projectile of choice seems to give
closer numbers to real world data when get to the range.

Would have to agree, 8208 is too fast for the 185's.

 

[Deadshot2]

Would have to agree, 8208 is too fast for the 185's.

But the RL-17 is a great powder for them. Now if I could only get more of both.