155 Lapua Scenar recipe

[Lynum Up]

After my Question on .308 @ 1000yds. over on the competition board, I've since orderd 2 boxes of Lapua Scenar 155's to shoot out of my 30'' 1 in 12'' twist short throat (palma 95) chamber. Any good starting recipes? I'm thinking of using - win cases, trim length 2.00'', CCI BR-2 primers, around 45gr Varget. Should I set the bullet out to touch the rifleing, or is it best with these bullets to have a few thousands jump? ??? ???

 

[Steve Blair]

2.00" is pretty short for most .308 chambers. Get one of the Sinclair chamber length gauges and trim .010 back from true chamber length.

http://www.sinclairintl.com/.aspx/pid=32925/Product/Sinclair_Chamber_Length_Gage

As for jump, every barrel is different. I start a load series at .010" back but have found some barrels perform better with a jump up to .040, some jammed as much as .020" Following is what Erik Stecker of Berger had to say about VLD seating. The same advice usually applies to other bullet forms.

QUOTE

Trying to find the COAL that puts you in the sweet spot by moving .002 to .010 will take so long
the barrel may be worn out by the time you sort it out if you don’t give up first. Since the sweet
spot is .030 to .040 wide we recommend that you conduct the following test to find your rifles
VLD sweet spot.

Load 24 rounds at the following COAL if you are a target competition shooter who does not
worry about jamming a bullet:

1. .010 into (touching) the lands (jam) 6 rounds
2. .040 off the lands (jump) 6 rounds
3. .080 off the lands (jump) 6 rounds
4. .120 off the lands (jump) 6 rounds

Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with
your rifling while in the field can be a hunt ending event which must be avoided) or a
competition shooter who worries about pulling a bullet during a match:

1. .010 off the lands (jump) 6 rounds
2. .050 off the lands (jump) 6 rounds
3. .090 off the lands (jump) 6 rounds
4. .130 off the lands (jump) 6 rounds

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality
of this test is that one of these 4 COALs will outperform the other three by a considerable
margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL
+/- .002 or .005. Taking the time to set this test up will pay off when you find that your rifle is
capable of shooting the VLD bullets very well (even at 100 yards).

Regards,
Eric Stecker
Master Bulletsmith

UNQUOTE

 

[Lynum Up]

The 2.00'' number is the length I've been trimming my cases to. My overall length, with bullet, (coal) is 2.780 in my chamber using a Hornady Lock N Load OAL gauge.

 

[Steve Blair]

Yes, I know that 2.0 is your trim length. What I was trying to say was that most .308 chambers are much longer than the SAAMI 2.025 mimimum. My .308 chambers are 2.034, 2.038, 2.039 and 2.040. Trimming to 2.0 would leave .034 to .040 forward of the case to collect carbon and promote erosion of the chamber-freebore transition. That is a difficult area from which to remove carbon.

As for the load: 45.0 Varget is likely to be a compressed load, even seating .020 into the lands. A faster powder would probably provide better results at that bullet weight. H4895, IMR 8208 XBR, Reloder 12, VV N530 or Win 748 are likely candidates.

 

[ohearchai]

Sleepygator, excellent information thanks for sharing.
Marty

 

[Lynum Up]

Sorry Sleepygator, I didn't mean to sound ignorant, have been working to much and reloading to little. The 2.00'' number came from my gunsmith who chambered and installed my barrel. Maybe he was just throwing a number out at me. I'll take your recomendations, and actually measure the chamber like you said. Thanx for your input

 

[Steve Blair]

No apology needed. I was just annoyed that my first attempt did not make the point. I sometimes write as if I was talking in person and fail to include enough information.