Home Forums Hunting & Shooting Ask The Gunwriters Handloading the 7x64.

G'day John and everyone.

I had a Ruger tang safety rebarreled to 7x64 (23" brl) and took it to the range yesterday. I loaded 150gn Ballistic Tips with H4350 and H4831sc. I used Hornady data from their #10 manual. I worked up to 52gn H4350 for 2760fps. Hornady list 51.5gn H4350 for 2700fps in a 22" barrel. Considering the extra half a grain of powder and an extra inch of barrel I'm right where I should be I guess.

I tried loads with 57gn H4831sc (2714fps) and 58gn H4831sc (2731fps) for a gain of only 17 fps for the extra grain of powder. I had rounds loaded with 59gn H4831sc but didn't shoot them due to the small increase in velocity from 57gn to 58gn. I thought I might have been getting close to max, but the velocity seems quite low. The 58gn and 59gn loads were compressed as the 150gn Ballistic Tip is a long bullet and I've sat them out with only a couple of millimetres left in the magazine box.

My velocities (and Hornady's too) seem low from a cartridge similar to the .280 in a 23 inch barrel. I looked online and found RWS and Norma factory loads loaded to 2850 - 2950 fps with 150gn bullets. The 7x64 has a very long throat (my gunsmith looked at my reamer and reckons it's the longest throat he's ever seen) so would this be keeping velocities down?

Can I increase loads to get around 2850 -2900 fps with 150gn bullets in a 23" barrel? Which powder would you suggest? I have H4350, H4831sc and Re19 though I think there's not a lot of room to load more H4831sc as 58gn was compressed. I haven't tried Re19 yet but will next week. These loads are slightly lower than what I get in my 22" 7x57 so I assume I am safe to add a grain or two more powder and see what happens. Any reason why the Hornady data is conservative? I thought the 7x64 may have low pressure limits set by CIP but the RWS and Norma factory loads suggest it can be souped up a bit. I don't want to turn it into a 7mm Magnum but 2850 - 2900 fps would be nice.

Thanks John and everyone else who can offer some advice. I understand you may not have much experience with this cartridge but it is similar to the .280. Please note I don't have access to the huge range of powders you guys have over there so am limited to the three powders mentioned above.