.308 win F/TR chamber

[cmillard]

I turned the necks to .012 thickness

 

[marine52]

I turned the necks to .012 thickness

Holy smoke! No wonder your group opened up.
So you have a .342” chamber neck and your normal brass neck thickness is .014” for a total of 0.028.” That gives you 6k neck clearance which is more than needed. If you turned an additional .004 off that means you had 10k neck clearance in the chamber.

 

[D-4297]

Yea for 300 -500 and no wind

The N-150 works in the wind , with a good triggerman , too . Shot a 198 - 10X at Ben Avery the other day , in 8 -10mph . Gusting to 15mph , and switching from E - to SE . At 600 yards , using a Berger 185gr Target Hybrid .
It ain't the arrows , Cochise !

 

[cmillard]

The only reason I did that was I had 7 pieces of brass after sorting that was an outlier from the rest. I took those 7 and turned them from .014 to .012. Which resulted in the 2" group. The biggest change was from seating the bullet in my normal brass out an extra .010 which had the 5" group......my normal load gets me about 1/4" at 110 yards

 

[marine52]

The only reason I did that was I had 7 pieces of brass after sorting that was an outlier from the rest. I took those 7 and turned them from .014 to .012. Which resulted in the 2" group. The biggest change was from seating the bullet in my normal brass out an extra .010 which had the 5" group......my normal load gets me about 1/4" at 110 yards

If you are getting 1/4” groups at 110 yards with federal brass and a 5lb trigger, I’d say you’re doing pretty good. But you may want to try lapua or Alpha brass. My lapua 308 brass averages about .0145-.0146 neck thickness. Alpha may be more. As @Acyr said, you have a no-turn neck. Also, a new trigger can only help.

 

[cmillard]

I have been eye balling alpha brass, just haven't squeeze the trigger on any yet. As far as trigger goes, yes it is much heavier than what i want and am used to but it is manageably heavy. Honestly, im not exactly sure what the chamber nk dimensions are and honestly not too worried about it. Pretty much all of my federal brass hovers around .014 thickness and figured with those 7, i would just see what it would do.

 

[Killick]

45.5gr N150, 155gr Berger VLD, Lapua brass, Murom LRP, 1in13 twist____.25 moa at 800yards, Sling/Palma competition.
More good info from Laurie:

Post in thread '308 Rifle Barrel Twist'

Jan 16, 2025

308 Win was introduced three-quarters of a century ago and bullets have changed vastly in that time. Our understanding of optimal rotation (hence twist rates) has also moved on mostly thanks to work by Bryan Litz and his company Applied Ballistics.

Until fairly late in the 20th century, bullet component and manufacturing quality were very poor by today's standards from most makers with many having inconsistent thickness / weight jackets and similar issues. Such 'out of balance' examples were very spin-rate sensitive as they veered off the aimed trajectory in any circumstances, but even...

• Laurie

• 

 

[cmillard]

I just got done shooting. Got my hands on some 6.5Staball over the weekend from one of my brothers. I loaded up 7 rounds with 215 bergers with 7 different charge weights to see where pressure started. I didn't see pressure anywhere and all 7 shots were in a cluster that showed .75" vertical. Debating on whether to load some up and test for groups and check velocity or do some H4350

 

[cmillard]

Shot 2 five shot groups today before heading out for work with the 6.5Staball loads. The wind was absolutely atrocious, but realistically the only thing it effected was paper target it caused to move around. 25-35 mph was a chore but, the last load shot pretty decent. 5 shots into .75. I will do some more testing with this powder as I think i can shrink that group and will try my H4350 and Accurate 4350 next.

 

[cmillard]

StaBall is showing some promise

 

[Codyway]

What bullet? Velocity?
I've never used stabal in 308

 

[cmillard]

215 grain berger hybrid. I haven't chronographed that load yet, but based on the previous lighter charges, it is in the neighborhood of 2400-2410 fps

 

[paulT]

It will, until it gets hot. Back in the Varget drought in about 2013 before we found N150 it was tried by a lot of people. That is the reason I discovered and started shooting N150 in about 2015.

Hi XTR
Which powder you find gives best results for Longrange FTR with 208g and 215g hybrids Varget OR N150.

 

[cmillard]

Going to jump in before XTR answers. I think varget and N150 are a tad too fast for 215s. I'm testing 6.5 StaBall now and will try one of the 4350 flavors also

 

[Acyr]

Going to jump in before XTR answers. I think varget and N150 are a tad too fast for 215s. I'm testing 6.5 StaBall now and will try one of the 4350 flavors also

N150 works fantastic with 215's.

 

[cmillard]

Acyr, i guess I should have answered a little different. It depends on what best results would be defined as. Pure accuracy, speed, or a combination of both? I did get terrific accuracy with N150 and 215s, but I saw pressure before I liked with those loads. I'm not done with N150, as I will try that when I get some 200s.

 

[LVLAaron]

You're gonna go through all of this and find out that N150 and 200's are the answer.

 

[memilanuk]

You're gonna go through all of this and find out that N150 and 200's are the answer.

Probably not. He's already demonstrated that he thinks he knows better than anyone who has gone before.

 

[cmillard]

You're gonna go through all of this and find out that N150 and 200's are the answer.

Honestly, that is fine by me. It really doesnt matter. I like tinkering with loads.....I can't leave well enough alone.

 

[cmillard]

What bullet? Velocity?
I've never used stabal in 308

I just got back from the Rocky Mountains this morning and went out and chronographed that load after I woke up. Surprisingly, this charge was slightly slower than the previous lower powder charge by 6 fps. Had an average of 2376 fps. Not sure what to make of it.