185 juggernauts and seating depth

[wolfman]

I've got 2 F/TR rifles that simply won't settle down and shoot like they should.

In the past, I've always seated 185 juggernauts over H4895, N150 or Varget, in Lapua cases, bumped 0.001 in a Type S FL die with a .335 bushing, and gotten good results.

Brass is once fired. Best results are currently with Varget. extreme spread over 10 rds is 10fps, but groups are .75 moa at 100m!

Barnard S actions, one with a Rock 1-10" barrel, other is made by a local guy just starting out. Both chambered by the same, very reputable 'smith. NF BR and Sightron 10-50 scopes.


Both chambers were cut by the same guy, with the same tooling. Could it be something like the leade angle?

If going with tweaking seating depth, where do I start? Try the Berger VLD depth test?

 

[savageshooter86]

I would start at 10 jump and work further off until accuracy is there. Mine shoots lights out at 20 jump. Most are jumping them. Mine shot well at 15 jump too. My CBI barrel right out of gate just thrown together load initially shot under 0.45". That was just to see if it will shoot, no load work.

That bullet/powder combo should be shooting better than 0.750

 

[Down South]

Both my FTR guns shot the juggernauts well, very well, with .010 to .020 jump and Varget.......One barrel is a Krieger, other is a Brux and different reamers were used on both.......One was 11 twist, the other was 10 twist.

 

[wolfman]

Your experiences mirror mine from past rifles. I'm tearing my hair out here!

 

[Keith Glasscock]

I usually start with .005" of jump and work back in .003" increments. My rifle likes triple-nickels and 200 hybrids @ .015" to .018" off (jump).

Some leade angles work better than others according to the folks smarter than I. I use 1.5 degree. If in doubt, back down the charge, push the bullets into the lands and work the charge back up. If it shoots there, the leade just doesn't like jumping that bullet.

BTW, what is the freebore? What is your COAL right now?

If you don't have any bullet bearing surface supported by the freebore, it won't shoot consistently. Ask me how I know :

 

[wolfman]

Base to Ogive- barrel #1- 2.345 to the lands, Barrel #2 2.315

If anything, the longer throat shoots a tad better.

A team mate just suggested that I might be having head/eye position issues. I think I'd feel better if it's me, and not the rifles!

 

[savageshooter86]

let someone else shoot the load and see what it does

 

[Keith Glasscock]

Sounds like it has plenty of freebore.

Chamber is normally 2.025
.342 neck to .3085 transition is ~.016"
The leade also increases length some.

Definitely let someone else shoot them.

 

[savageshooter86]

has this load shot well prior? Or change anything on this current load?

 

[skiutah02]

Try here and a series of posts after.

http://forum.accurateshooter.com/index.php?topic=3814361.msg36429034#msg36429034

I did an OCW test with the 185s including a seating depth set and included a few pics of targets. Summary: used 0.020" jump as a starting point to test and ended up at 0.015" as others have indicated. However my base to ogive with 0.020" jump is 2.220". Hope this helps rather than confuses. Drew

 

[wolfman]

I finally made it back to the range, and ran a seating depth test. from 0.015 off, to 0.015 into the lands. It was like I was shooting a new rifle- 0.015 off to 0.005 in all printed well under 1/2 minute, and 0.015 off was 1/4 moa. Now to confirm at 900m tomorrow, and then crank out 300 rds before tuesday morning....

I should also admit that I discovered my scope eye relief was off, and correcting it really made things much more comfortable, and therefore, quite likely, more consistant.

 

[Dos XX]

Good to hear. I was going to say make sure you have a 308 barrel on it.

I haven't seen a 308 that won't shoot Juggernauts over Varget. Might could happen, though.

 

[Down South]

I finally made it back to the range, and ran a seating depth test. from 0.015 off, to 0.015 into the lands. It was like I was shooting a new rifle- 0.015 off to 0.005 in all printed well under 1/2 minute, and 0.015 off was 1/4 moa. Now to confirm at 900m tomorrow, and then crank out 300 rds before tuesday morning....

I should also admit that I discovered my scope eye relief was off, and correcting it really made things much more comfortable, and therefore, quite likely, more consistant.

Good to hear you got it going.