I just got a new 7x30 barrel and have been shooting for probably 3 weeks now with factory loads and also a load that I developed. I plan to hunt antelope with this barrel.
Factory loads in my barrel shoot groups in the 1 1/4-1 3/4 inch area. I just clocked them yesterday and they have a speed of 2386 FPS.
I started developing my handload using factory brass, the 120 grain Nosler BT, 748 powder and Federal 210 primers. The Lyman 47th edition of their manual says that 39.5 grains is max so I started at 35 grains and worked up. My barrel has a very long throat so I knew from the beginning that it would use lots of powder. Lymans COL was 2.550 inches and mine was 2.850 and I still wasn't close to the rifling. I arrived at 39.5 grains of powder and just quit. I was measuring the case expansion directly in front of the rim and about 1/4 inch in front of the first measurement. With 39.5 grains I still wasn't getting as much case expansion as the Federal load gives. For me that indicates that more powder could be added. Maybe at a later date.
Well anyway day before yesterday I checked my load for grouping ability and it shot 1 1/8 to 1 1/2 inches. Yesterday I checked the speed and a 3 shot average was 2492 FPS.
This seems like a good load for this barrel but "CAUTION"!!!! As I stated, "my barrel has a very long throat". Your barrel may not be able to use this much powder, be careful.
Regards, Keith