WB
Loading for the 5.7X28 will NOT be for everyone
Wednesday, March 04, 2020, 10:47

It sounds like fun but I have enough irons in the fire right now. It's mostly about attitude and experience. On a blow-back gun you cannot "enhance" performance by loading hotter. All you can focus on is making the platform function (barely is best) and then the performance outcome just is, what it is. Sort of like loading rounds with Trail Boss, you just end up with what you do and focus on accuracy. I do really like the Ruger engineering manipulating a "delay" on the blow back enhancing function and safety. It looks really good as a design.

You can manipulate the bullet weight, up or down, but still the focus is on barely making the action work. Normal performance parameters like speed and energy are out the door. You cannot manipulate the outcome as normal. The 5.7 brass is super thick, a good thing. It is less likely a blown web would occur, there is some safety built in. The projectile has to be far enough down the bore to lower pressures before the action is opening and exposing a weak area of the brass case. Too fast opening and BOOM! A blown case. I have not read the Ruger manual on their new 5.7 but I am certain any reloaded ammo would be most highly discouraged. In this case it's not just a legal liability footnote it's actually sage advice!

You truly need to know what you are doing loading for a blowback round like the 5.7x28. Tiny variations in powder weight make big changes since there is not much to begin. A good Benchrest powder measure would really help. You would want to control down to 1/10 grain if you could. I see the 5.7 pushing a 40 gr. about 300-400 fps faster than a .22 WMR, and about 300 fps slower than a .224-32FA or .224 K-Chuk revolver. Not a bad range in performance given the convenient platform. Sounds like fun.

It will be interesting to see what transpires with time.