Blew my toy budget
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Vaughan
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analog_peninsula
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Re: Blew my toy budget
From left to right:
8x65r case then 7x65r opened up to 8mm then a fired 7x65r then an unfired round.
Annealing and imperial sizing wax made running the fired 7x65r cases through the 8x65r sizing die a breeze. No cases were lost in the process. The opened case is about 10 thousandths shorter than the native 8x65r brass, and the shoulder is somewhat further back and will move significantly forward when the cartridge is fired. Most load data favors either n150, n160, n540, and n550, but a number of other powders are used in similar cases like the 8x57 and the 8mm-06. I put together starter test loads using h4350, aa2700, big game, Staball 6.5, and imr 4064. H4350 supposedly has the lowest pressure, but I expect on of the faster powders to provide better convergence as I work the loads above 2500 fps. Nominal velocity with 200 grain bullets is 2625 fps or ~800m/s, but historical chronograph readings are usually optimistic and run at least 100 fps high. In any case, convergence is much more important than velocity in a double.
Wish me luck.
8x65r case then 7x65r opened up to 8mm then a fired 7x65r then an unfired round.
Annealing and imperial sizing wax made running the fired 7x65r cases through the 8x65r sizing die a breeze. No cases were lost in the process. The opened case is about 10 thousandths shorter than the native 8x65r brass, and the shoulder is somewhat further back and will move significantly forward when the cartridge is fired. Most load data favors either n150, n160, n540, and n550, but a number of other powders are used in similar cases like the 8x57 and the 8mm-06. I put together starter test loads using h4350, aa2700, big game, Staball 6.5, and imr 4064. H4350 supposedly has the lowest pressure, but I expect on of the faster powders to provide better convergence as I work the loads above 2500 fps. Nominal velocity with 200 grain bullets is 2625 fps or ~800m/s, but historical chronograph readings are usually optimistic and run at least 100 fps high. In any case, convergence is much more important than velocity in a double.
Wish me luck.
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SPEEDY
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Re: Blew my toy budget
Fiddly, shame you can't just buy the right cases, but old guns can be a bit like that, and I think it makes shooting them more enjoyable. Instead of just buying ammo, you have to craft your own.
I think Bertram brass here might make them, they specialise on older and obsolete cases, if they are still in business that is.
I think Bertram brass here might make them, they specialise on older and obsolete cases, if they are still in business that is.
I'm soft and I don't care. 
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analog_peninsula
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Re: Blew my toy budget
To the best of my knowledge, I found and bought the last 100 Bertram 8x65r cases available for sale in the US. If anyone stumbles into any more please don’t hesitate to pm me as a few more would be nice. Realistically, I only need properly headstamped cases for international travel, and I don’t have any immediate plans involving the Triebel.
I shot test loads with five powders on Saturday in order to get some sort of pressure baselines. Generally speaking, an 8x57 recipe runs ~150 fps slower in the 8x65r. Three of my loads ran ~2300 and two ran ~2200. For proper convergence, I will likely need velocities between 2475 and 2525, so the next step is to modestly up the powder charges and retest. Recoil felt very modest, and all signs indicated low chamber pressures, as you might expect.
I shot test loads with five powders on Saturday in order to get some sort of pressure baselines. Generally speaking, an 8x57 recipe runs ~150 fps slower in the 8x65r. Three of my loads ran ~2300 and two ran ~2200. For proper convergence, I will likely need velocities between 2475 and 2525, so the next step is to modestly up the powder charges and retest. Recoil felt very modest, and all signs indicated low chamber pressures, as you might expect.