MNbogboy
Well-Known Member
Ressurecting this post. Just had to try this.
Initial thoughts there may be something with this wildcat.
My old 260 Shilen set back .250 and then chambered with 6.5 CM approximate .080 deep. Brass is new Hornady 7-08 sized in std creedmoor dies and trimmed to 2.005.
The shorter round allows the shoulder to transform the 20° 260 neck to the CM 30° almost perfectly.
Preliminary H2O capacities increased from 50.6 grs in fireformed std CM case to 52.6 grs in sized only "long" case.
No load development yet but bore sighted this with the magneto speed on. Started with a "known" CM decent load for some of my other creeds.
42.5 grs. H4350, 130VLDh, .010 off, cold clean barrel = 2857
43.0 grs = 2872
43.5 grs = 2872
44.0 grs = 2913 (no pressure indicators)
The 4 bore sighted only are at 50 yards.
Proceeded on to 100yds with 5 more at 43.5 grains. No change to scope.
2891
2869
2886
2892
2875
Fireforming 2883 ave ES 23, SD 9
For brass that was not weight or volume sorted yet this combination looks like it has some promise.
The top picture shows the difference between the 260 rem (left), "the subject" and the 6.5 CM (right).
Initial thoughts there may be something with this wildcat.
My old 260 Shilen set back .250 and then chambered with 6.5 CM approximate .080 deep. Brass is new Hornady 7-08 sized in std creedmoor dies and trimmed to 2.005.
The shorter round allows the shoulder to transform the 20° 260 neck to the CM 30° almost perfectly.
Preliminary H2O capacities increased from 50.6 grs in fireformed std CM case to 52.6 grs in sized only "long" case.
No load development yet but bore sighted this with the magneto speed on. Started with a "known" CM decent load for some of my other creeds.
42.5 grs. H4350, 130VLDh, .010 off, cold clean barrel = 2857
43.0 grs = 2872
43.5 grs = 2872
44.0 grs = 2913 (no pressure indicators)
The 4 bore sighted only are at 50 yards.
Proceeded on to 100yds with 5 more at 43.5 grains. No change to scope.
2891
2869
2886
2892
2875
Fireforming 2883 ave ES 23, SD 9
For brass that was not weight or volume sorted yet this combination looks like it has some promise.
The top picture shows the difference between the 260 rem (left), "the subject" and the 6.5 CM (right).
