Damn I love this type of innovation.
As will all great projects, let discuss the downsides of steel based “hybrid” cases?
- Multiple reloads? More or less than brass?
- Die wear?
- Bolt, extractor, chamber wear?
- Obviously will burn barrels faster with higher pressures/ velocities?
- Longer term storage with mixed dissimilar metals?
- Any other downsides?
Pros
- Base on the first question primer pocket hold up indefinitely?
Are you actually sizing the steel or just neck sizing?
Thanks again for your info on this.
Probably can’t answer all the questions, but a few. The FL dies never fully sizes the last .2" of the solid case head.
The first pic is a fully resized 308 case...notice the die never touches the last .2" this portion of the case is solid hardened brass, with only the primer cut out then the flash hole through the center.
It never gets sized, on brass or stainless steel.
This solid portion does not expand under normal chamber pressure.
Next pic the brass portion expanded 4 1/2 ten thousandths of an inch. This expanded portion and the rest of tbe case is the part that the FL die resizes.
An actual 308 factory chamber, with the cartridge case inserted...note the solid head portion iof the case is not supported by steel. Repeated high pressure loads or one really high pressure load expands the solid head, so it will no longer hold primers.
So the stainless steel solid case head never gets resized, just like the solid brass case.
I'm personally doing alot of other projects, but I have cycled the Stainless steel case head through 5 high pressure cycles and primer pockets are still tight.
Don't have to worry about die wear.
I store them in 50BMG military cartridge storage containers.
I checked headspace for lug set back, ...no change, on 2 factory rifles I really pushed hard, for experimental purposes.
On normal pressure loads the primer pockets, may last until the brass case gives out.
The brass will start to seperate near the head or down the body after repeated firings, no matter how little one resizes the case each time. When you trim the brass comes from the case stretching slightly, anf brass flow towards the shoulder making the body thin.
Example, years back, after 40 to 50 firing resizing cycles on Lapua brass the case is so thin it seperates, even with neck sizing only with a shoulder bump die every third firing. So with that setup I scrapped the 308 Lapua brass after 40 cycles... max for this loading proceedure.
You have to trim cases after the first firing the 3 piece SS case tends to stretch, more than normal first time under pressure.
Do Not forget to lube this hybrid case or think it has has enough lube when it doesn't...they are strong but will seperate. The case head and the body left in the die.
To get the broken shell our take the die to the lathe, bore for 7/16 X 20 tap, tap in lathe to keep exactly centered. Use bolt & cup method to pull stuck case.
No noticeable wear on any rifles from Stainless case heads.
Barrel wear will most likely be greater...but that would be an exhaustive test to see if a 6.5 CM with higher pressure and slightly less powder would out last a 6.5 PRC burning 5 grains more RL 26 to get the same velocity. Probably about equal...maybe.
No excessive wear on rifle parts from various calibers noticed.
Remember the military runs this high pressure ammo in machineguns, and slect fire rifles for soldiers.
A semi auto civilian version is available to the public complete with suppressor and 13" barrel, for a hefty price.... 6.8X 51 able to penetrate Russian body armor.
Don't have all the answers, this is a hobby, and what I have learned...learning new things every day....it's up to you, and others, to add more to the experience.
