load development

[eddyverhoeven]

I had a new Shilen brl installed on my 300m free rifle in cal. 6mm BR,1 in 8 twist). In order to develop an accurate load in it should I start with new,sized, chamfered and deburred) or with once fired Lapua brass?

I intend to load the 105 gr Lapua,moly) and the 105 Berger VLD,moly). Should I start with a different distance from the lands or could I use the same,say .012" from the lands) for both bullets?

Which of the following component combinations would be best to start with?

Powders : Norma 203B, Vihta N140, Vihta N540, Varget

Primers : Fed 205 gold medal, CCI BR4, CCI 450, Rem 7 1/2

Any suggestons are welcome

Eddy

 

[JamesnTN]

Eddy,

Typically the VLD bullets like to be jammed into the lands where as the bullets like the Lapua and Sierras I had found likes to be jumped from .005-.015 off lands. Now this isnt always true but n most cases I have found the lapuas and Sierras both like to be jumped.

If you go to the thread spring back here and go to page 3 and read my load developemnet techniques you may find it helpful in helping you find your most accurate load.

 

[Forum Boss]

Eddy, since you can get the great Norma 203B, I would start with that and CCI450s. When testing with naked 105 scenars, 203B gave the lowest ES/SD and a very broad and flexible accuracy window,i.e. great accuracy from 29.5gr to 30.5gr). Varget is less temp sensitive and would be my next choice of the powders listed. I haven't tried N540, but many people really like it with moly bullets.

Since you are using moly, you may find your best load near the high end of the scale.

I would start both bullets .010" into the lands and then play around. The Lapuas should also shoot well .007-.015" away from contact, but that will reduce your case capacity a bit.