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Load Data with Remington 700 .308, TR140 and Lapua B476s..

Posted: Wed Jul 23, 2014 8:37 pm
by paulbradley
Ran some load tests today which I thought I would share. Obviously I worked up slowly and safely to these loads checking carefully for pressure signs on each shot. I felt for heavy bolt lift and inspected each piece of brass. No pressure signs detected. My aim today was to push the 170g B476s a bit harder as I want to use them at longer ranges than I have done previously. The results were pleasing. 3 shot groups down to .358MOA.
I had some issues with shadow after string 3 and rectified this in string 5 as you will see below.



Load Testing 23/7/14 .308 Win

Rifle: Remington 700 SPS action and barrel, 26" 1-12 twist, Manners T5 stock, Badger Ordanance pillar bedded mini chassis, Recrowned by SYSS.

Scope: Vortex Viper PST FFP 6-24.

Weather: 77F, 2.978Hg@115ft Sunny. Light 2-5mph wind from 4 'O clock.

Ammunition: Lapua .308 Brass, once fired and neck sized to Reddings 335 bushing. Deburred, chamfered, pockets cleaned. Lapua 170g LB B476 bullets seated at 2.833" TR140 powder, CCI LR primers.

Crono set up 10ft from muzzle.

44.8g: 2604, 2583, 2576
44.9g: 2709, 2731, 2732
45g: 2783, error, error
45.2g: 2809, 2756, 2740
45.4g: error, error, 2624

Chrono repositioned as shadow cast by the roof began to cut across the sensors and cause errors.
Chrono set up 5ft from muzzle.

45.5g: 2688, 2704, 2699
45.6g: 2715, 2699, 2732
45.7g: 2724, 2787, 2745
45.8g: 2726, 2721, 2743
45.9g: 2766, 2760, 2726
46g: 2741, 2754, 2760
46.1g: 2777, 2731, 2751
46.2g: 2772, 2754, 2777
46.3g: 2754, 2755, 2754
46.4g: 2799, 2754, 2766

No pressure signs at all.

Re: Load Data with Remington 700 .308, TR140 and Lapua B476s

Posted: Wed Jul 23, 2014 8:50 pm
by ovenpaa
What was the group with 46.3 grains like?

Re: Load Data with Remington 700 .308, TR140 and Lapua B476s

Posted: Wed Jul 23, 2014 8:55 pm
by paulbradley
46.3 - .501MOA 2 shots in one hole with a flier just off to the right. Can't discount the wind as it began to gust during the latter strings..

Re: Load Data with Remington 700 .308, TR140 and Lapua B476s

Posted: Wed Jul 23, 2014 9:05 pm
by paulbradley
46.3 certainly warrants further investigation as the MVs seemed to level out nicely there. I should add that all reloading was done as carefully and accurately as my gear would allow. Some of the large deviations surprised me. The 28xx in the early strings I believe was in error. I need a magneto Chrono thingummybob!!