Quote:
Originally Posted by 260 Rem
None of the brass is likely to have excessive HS. Everything in both lots is the same except for the number of reloads. I have plenty of experience with the 6 Dasher (think I have about 6 barrels chambered with my reamer). Also pretty confident the load is not low pressure or it would not drive the 95 gr close to 3000fps from a 23" barrel). With 105's and the same volume of powder I get about 2975 fps from a 25" barrel. When I load the Dasher with a 105/33.0 gr combination and get velocities approaching those of 243 Win ...with 10 grs less powder ... which can only be done with a lot of pressure.
Now, if one was looking for a top notch varmint rig, the Dasher kicks butt. I think it (and it's variants) still dominate 600yard International BR Shooters competition. Even their 1000 yard completion is likely to have a greater number of this "improved" cartridge than any other show up in the top 20.
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I am just trying to get to the bottom of why the brass made a difference. The brass you pictured in the calipers has Excessive HS. In another post you said that some of this brass had been fired warm and I have had extensive experience with measuring brass that have been fired with different pressures. FL dies have to be set to compensate for the uneven spring back at the shoulder datum where HS is measured and cannot be assumed in this case.
Also the Hodgdon Manual shows 90 & 100 grain loads running to 3229 fps and 3088 fps respectively. in a 30" barrel. Pressures run at about 52,000 Cup, which is like a 7mm-08, with a powder of similar burn rate to your 95 grain Berger which is likely running less pressure than that at 2975. I never said that your load was running low pressure, just not high enough pressure to fire form the brass and slam the primer against the bolt face and flatten it as in your other brass.
Like my 20 EXTREME which gets velocities approaching the 204R, with an equivalent % less powder (4-6grains), the 6 Dasher is a very well balanced cartridge design. I believe that they are much easier to find Good Loads for as well. The only difference is that I Improved it by actually making a 222R case smaller and forming the shoulder with my dies. This eliminates fire forming and brass is always formed the same after firing.
I have known about the 6 Dasher practically since its introduction and know that the boys down in Montana kicked ass in 1000 BR. However as a 500 yard varmint gun I would pick the 20 EXTREME due to its lower muzzle velocity and powder consumption. As far as wind age and elevation they are very similar to that range. At longer range the 6 Dasher would be the winner.