Gary Reeder
did a bit more load and ballistic testing on the new
Friday, November 16, 2018, 22:21

257 Firecat this evening. Mainly case capacity which to me is the main thing when developing a new cartridge. That will tell me if the cartridge has any improvement possibilities over it's next closest competitor. I was pleasantly pleased with the results. Here is what I found...
The case capacity of the new 257 Firecat is 58 grains.
22-250...44.5
6.5 Creedmoor...52.5
6.5 X 55...52.5
7-08...54
243...52
260 Remington...51.5
250 Savage...45.5
35 Remington...47.5
257 Rbts...57
284 Win...62
Now remember these are not the load data. This is simply the total case capacity of the cartridge to the mouth of the case.

I knew the 284 had the capability of beating my 257 Firecat but wanted to see how bad. The 6.5 X 55 seemed to be a duplicate of the 6.5 Creedmoor. The closest cartridge to the same case capacity of the 257 Firecat was the 257 Roberts.
Now to get a test barrel made and to Sean so he can tell me whether or not it is a viable cartridge. I am already fairly sure it will do fine in an AR-10 as we have already run quite a bit of ammo thru the test AR. The AR-10 is what I developed it for, but it will be interesting to see what it will do in a 20" Encore barrel.