.308 Load testing questions

[NoahbodyImportant]

Today, I did some load testing with my Magnetospeed V3:

Min: 2834
Max: 2853
AVG: 2845

S-D: 6.9
ES: 19

Savage F-Class .308 with 30" Bartlien Barrel 1:11

Lapua Brass
44.3gr Varget
CCI BR2
175gr SMK

.030 jump
.003 neck tension

With the bayonet attached, I had just over an inch vertical in 10 shots at 600 yards. When I took the bayonet off, the group opened up and POI dropped at least 5 inches.


Is 2845 FPS a bit warm? What FPS should I be trying for?
Should I try .002 neck tension? Since switching to Laupa brass I do not have the appropriate TiN bushing at this time.

I have played with jump vs jam, but will try again with different neck tension.

Should I leave as is?

 

[JamesnTN]

My load is 42.6 grns IMR 4064 F 210m primers in a Lapua case and Sierra 175 Mk it'll shoot sub 3" at 500 out of an accuracy intermational

 

[Turbulent Turtle]

Today, I did some load testing with my Magnetospeed V3:

Min: 2834
Max: 2853
AVG: 2845

S-D: 6.9
ES: 19

Savage F-Class .308 with 30" Bartlien Barrel 1:11

Lapua Brass
44.3gr Varget
CCI BR2
175gr SMK

.030 jump
.003 neck tension

With the bayonet attached, I had just over an inch vertical in 10 shots at 600 yards. When I took the bayonet off, the group opened up and POI dropped at least 5 inches.


Is 2845 FPS a bit warm? What FPS should I be trying for?
Should I try .002 neck tension? Since switching to Laupa brass I do not have the appropriate TiN bushing at this time.

I have played with jump vs jam, but will try again with different neck tension.

Should I leave as is?

Unless you intend to always use the Magnetospeed you should continue working on the load. Apart from that, the load looks very similar to mine except that my barrel is a little longer, I use a bit more powder and a much better albeit slightly heavier bullet and get about the same velocity. I have .003 neck tension now and I'm fine with it.

 

[amlevin]

Is 2845 FPS a bit warm?

The answer to that is on your end. Any pressure signs? If not your charge weight is still below the published max. Some barrels are just plain faster than what the test barrel at Hodgdon produced. You also have to take into consideration whether or not your Chronograph is properly calibrated.

I keep a box of Factory loaded ammo and use one round from the box every once in a while to "check" my chrono. The factory ammo has a published speed of 2700 fps so as long as I get something around 2675-2725 I'm OK with it's readings.

As it is, you're 150 fps higher, with .7 gr less powder. Might be 6" more barrel length, a fast tube, or tolerance in Chrono accuracy. In the end it will all be about pressure and being able to read the signs.