Reloading the 277 Fury 6.8x51 SIG Hybrid Case

[longrangelead]

Got out and got the other 50 fireformed, so I did a little volume test. I selected 10 random cases of each of the three headstamps. Weighed them on my Fx120i scale. Filled them with room temperature bottled water and weighed them again. Here are the results.

"22" Headstamp
Average case weight = 155.62 grains
Average weight when filled = 213.28 grains
Case capacity by water volume = 57.66 grains

"23" Headstamp
Average case weight = 165.22 grains
Average weight when filled = 221.98 grains
Case capacity by water volume = 56.76 grains

"24" Headstamp
Average case weight = 167.20 grains
Average weight when filled = 223.82 grains
Case capacity by water volume = 56.62 grains

What I am inferring from this is that the construction of the "22" headstamp differs from the "23" and "24" headstamp. So, if you plan on using a bulkier powder the "22" may be better for you, however it is the least prevelant in the 100 quantity boxes from American Reloading. The 23 and 24 are close enough that it shouldn't matter when loading them.

I plan to segregate the 22s from the rest of the brass and will work up a separate load for them, or just put them aside to sell later or use in a different application.

Oh, and still no indication of a ring. Fired three more of my regular brass cased rounds, one after the first 20 fireforming, one after the 40th, and one at the end.

I'd be interested in taking those 22's off you hands.

 

[khuber84]

Its getting pretty full but i did go higher.

Whats your process for forming these hybrid cases to 65cm? I tried a few and was getting crushed/wrinkled shoulders, using a bushing die. Some of them fireformed out, some did not.

 

[deerhunter628]

Whats your process for forming these hybrid cases to 65cm? I tried a few and was getting crushed/wrinkled shoulders, using a bushing die. Some of them fireformed out, some did not.

I just lubed the cases and sized them in my Hornady sizing die. I do not use a bushing die. I got a couple dented shoulders from too much case lube but most turned out good. I have about 4 cases that will not chamber. I think those cases need to be neck turned but im not messing with that

 

[HandgunHTR]

I'd be interested in taking those 22's off you hands.

I ended up having 69 (nice) of them out of the 400 cases that I purchased. As they have almost a full grain of powder capacity more than the 23 & 24 headstamped brass, I decided to start with them to keep pressures lower.

They have all been fireformed now and I am beginning load development with them.

For my process I am starting with 162 grain ELDX (remember 7-08AI) and my current loads with Varget and H4350 as my starting points. I am going to go up in .3 grain increments until I reach the load that is calculated at very close to 75K by GRT, or until accuracy falls off to the point that there isn't a reason to continue up.
Once I find a load that works, I will take some of the 23/24 headstamped brass and do the same to see how they differ.

Just a note for those who are buying the primed brass from American Reloading. If you get a piece of brass that has no headstamp at all (just clean steel), go ahead and knock the primer out and pitch it. The steel base is oversized at the 0.200 line, so it will not chamber correctly. I ended up with 3 of them in my last batch of 200 that I bought.