303/270
I currently have a 303/270 and a 303/22, both on the full length case. The 303/270 is a nicely put together sporter by Sportco, fully up to the standard of the Parker Hale sporters, and based on a 1917 Enfield MkIII*. Loading data is not all that good for the 303/270, 35gr of AR2208 (Varget) behind the 130gr Hornady giving around 2500fps. Going to put it over the chronograph this week with my handloads and about 30 rounds of "Riverbrand" factory loaded. The most popular round of the Australian wildcats based on the .303 case was/is the 303/25.
My 303/22 at the moment, it has a 28" long large diameter ex - BSA .22LR barrel. I am working on the 45 gr .223 projectile to begin with (barrel and twist limitations) with 34.5gr of 2208 for my current batch and fireforming as I go. I intend to work it up until the barrel throat is gone then get a TrueFlite in .224 and expand onto other projectiles and powders. It is pressure limited as it is based on a No4 action and not a P-14. If you don't think .22/250 and you regard it as a Super-Hornet and .223 equivalent, its about right.
Case forming is the pits, I was too cheap to buy the Simplex forming dies, so I start by FL sizing in the .303BR die, annealing a case, chamfer the end of the neck and using a Redding bushing die, put it into the .310 bushing, then the .288, then into the 6.5 x 55 die to adjust the shoulder, then into the .267, then - finally - into the .247, then Neck Size in the 303/22 NS die, trim to length, do a finish anneal and its finished. It is OK doing them in batches of 25.
How does it shoot ?. Lots more tweaking to do, but the average for the last 5 groups is 5/8" for 5 shot groups at 100yds. The 10 shot group yesterday opened out to 1.5" wide x 5/8" high (me wobbling) and a 3 shot group immediately afterwards had all three touching. I have a lot more to do in bedding the rifle and trigger work.
