Need 6 Dasher Load Help

[JamesnTN]

I'm trying to work up a load for my 6 Dasher with 107 grn bullets I have tested the Varget powder and just didn't like how it shot I was in the 34.0+ range with Varget using both Fed 205m and CCI 450 primers.

I just tested RL-15 with the 205m primers today and at 35.0 grns I popped a primer with a velocity of 3072 fps

Also tested VV 550 and it's trying but still not doing what I like I'm going back tomorrow and test both fed 205m and CCI 450 side by side using same powder charges beginning at 35.9 and going to 36.5 grns. 36.2 grns today with the 205m got me 3036 MV with ES of 10 fps.

I'm playing heck to get to 3000 fps as most folks seem to say it's where it likes to shoot. Not really any extractor marks but sure am cratering primers pretty good. I am using moly coated bullets if you're wondering why the higher powder charges than norm.

Question asked is what velocity do I need to realistically expect from a 28" barrel and what powder is most commonly used for the dasher and 100+ weight bullets?

 

[Forum Boss]

James,

I just talked with Scott Parker on the phone and we talked about your load dev questions. He just won his first match with his 6mmBRX. 30" Broughton BBL with 105gr moly Bergers or JLKs and Varget, Rem 7.5 primers. He was shooting his low node at 3045 fps, but he says he can also run them at 3120 or so. The extra 2" he has over your bbl might be worth 30 fps, and the 5C bbl contour might give him a little more Velocity also. But 3000 fps should be doable he thinks with your 28".

He's going to try N150 because it has a lower burn temp.

 

[flatlander]

James, I started with Varget in a 30" std. Palma contour Krieger 8-twist chambered for 6 Dasher with a .274" neck on a Nesika K. My fireforming load of 33grs. with moly'd S107s gives a tick over 2900fps. In formed cases, 34.1grs. gives 3010fps, and very good accuracy. When the DTAC 115s came out, I tried N150 & 550 with them, but decided to stick with 105-107s. N150 gets me to 3070fps with moly'd Lapua 105s; the last time I chrono'd, I was comparing R 7-1/2s to CCI BR4s, and both gave ES=6, SD=2, along with excellent verticals of 1"-1.5" at 600yds.

I also have a 28" Krieger on a M70 with a heavier contour,Winchester HV) that shoots very well with Varget/S107 at 600, but so far, loads with N150 in this barrel haven't shot as well as in the 30" bbl. Have just finished fitting & chambering a Broughton 28.5" 8-twist 5C bbl. on a trued M700, and will be doing some testing with it ASAP to find what loads it prefers. So far, all I've done is break it in with six rounds of bare 105s & Varget, plus a couple of 5-shot groups with moly'd S107MKs & Varget - hope the initial results are representative of how well this barrel's going to shoot, as I'm pleased so far.