What Velocity for 155 Bergers in a 30"

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Ganderite

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I am loading some ammo for my son. Varget, Lapua brass and 210Ms.

I usually put a 26 scope on the rifle and do the final load tweak at 600 yards.

Don't have that opportunity this year.

test today was 2984 fps. No pressure. ES 10.3 SD 3.6

But I don't know where the node is and won't be able to find out.

I gave him 3 loads, with 2 being 0.3 gr more and less. Hopefully one of those will sing to him.

Any evidence of a "magic" velocity?
 
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Shot 46.0 gr Varget today at Mons. Muzzle velocity over 20 shots averaged 2992 fps. No sure of the ES or SD number as I was using a friends Lab Radar. This was with naked 2156 SMK in weight sorted within .5 gr Lapua brass. Powder charge was 46.00 to 46.02.
This same load with moly coated bullets used to Chrony at 2940-2950fps.
 
Mostly shooting naked bullets this year ,but do have some moly coated Bergers for he long range challenge in Ottawa before the CFRC.
 
I think Nancy Tompkins ( US National champ a few years back ) says 2950-3000 was what to look for. Sorry, can't seem to find her book with that reference. I was just touching 3000 with 46.0 gr Varget using 155 Scenars, I'd think 47 is pretty warm and over 47 must be hot. Check with Maynard, he's way ahead of me with Target Rifle loads and shooting.
 
My son will be testing 3 loads (47.0, 47.3 and 47.5 of Varget) Velocity will be 2975 to about 3015. I am hoping one of them will stand up and wave at him.

I was wondering what the velocity node might be for a 30" barrel.

my barrels have been 32", so things have been a bit different.
 
maynard said:
Shot 46.0 gr Varget today at Mons. Muzzle velocity over 20 shots averaged 2992 fps. No sure of the ES or SD number as I was using a friends Lab Radar. This was with naked 2156 SMK in weight sorted within .5 gr Lapua brass. Powder charge was 46.00 to 46.02.
This same load with moly coated bullets used to Chrony at 2940-2950fps.
Click to expand...

Your average for 20 shots was 2992 fps. Your highest fps was 3006 at shot 8 and your lowest was 2977 at shot 4. Your extreme spread was 28 and your std deviation was 8.4.

Hope that helps.:cool:
 
I was hoping for lower numbers on the extreme spread and SD. With weight sorted brass all within 1/2 gr and each charge weighed to .02 gr. Looks like I may have to start weight sorting bullets now because I am not going to start cutting kernels of Varget.
 
accurate shooters site

Alliant Reloader 15 46.2 CCI BR2 Lapua 155 Lapua 2920 fps Very Accurate in 25″ 5R bbl, .3 MOA at 300m, 2.800″ COAL
Hodgdon Varget 45.2 F210m Lapua 155 Lapua 2830 fps Z. Smith Tactical Match Load in 24″ Accuracy Int’l, 2.850″ COAL
Hodgdon Benchmark 44.0 F210m Lapua 155 Lapua 2895 fps Jason Baney 100-400m Load
Hodgdon Varget 45.5+ CCI BR2 155 SMK Lapua
or Win 2950+ fps Jerry Tierney Palma Load
(Charge varies with lot)
Hodgdon Varget 47.0 CCI BR2 Berger 155 Lapua 2900+ fps John Whidden Palma Load
 
maynard said:
I was hoping for lower numbers on the extreme spread and SD. With weight sorted brass all within 1/2 gr and each charge weighed to .02 gr. Looks like I may have to start weight sorting bullets now because I am not going to start cutting kernels of Varget.
Click to expand...

Tom,

Can I assume you are using fire formed cases and using a Redding bushing die to size just your necks with little or no shoulder bump?

You might try starting with a bushing that is a little too big, then run all the cases through and check if any are tight enough to hold a bullet and those that will... put them aside in a bowl labeled bushing 0.333 (or whatever)

Then run all your remaining cases with the next smaller bushing and again put aside all that will hold a bullet. Put them aside in a bowl labeled bushing 0.332 (or whatever)

Repeat until all your cases have been brought just small enough to hold the round.

What this process does is threefold...

It ensures the necks are more parallel than going from a fired case to the final size. That creates a taper where the mouth will be smaller than lower down the neck.

It groups cases according to spring back / hardness of brass.

It sorts according to variations in neck wall thickness.

If you want more than just a bare minimum of neck tension, as you will have with the cases above, you could always go down just one more bushing than it took to hold the bullet.

I always found this process effective to result in the most consistent neck tension and therefore the lowest SDs on the Chronograph.

The cases that require the smallest bushing are probably the cases that could most use some annealing.
 
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