Patent from Federal covering case design of the new 7mm Backcountry

[akmtnhnt]

I'm also curious how you'd know for sure when your reaching max pressure working up a load with such a cartridge.

You cannot tell. You can't tell with the fury either.
You would need pressure testing equipment on the rifle.

You can estimate with QL or GRT, but at best those are estimations. There's another thread on here with a guy that has used pressure testing equipment and mentioned how poor these simulated estimates could be.

To be fair, you more or less cannot tell with brass either. By the time you're getting any sign on the brass, you're well over the limit. All reading brass tells you is that you should have stopped some time ago if you care about the saami pressure limit.

 

[AussieWriter]

One of the reasons for handloading is to avoid $50-60 a box of 20. We like to shoot more than a deer or ten a year.

The more that is said, assumed or offered, the more this looks like a factory ammo proposition which is a no sale, to the handloading market.

The other annoying fact is that there is no such animal that this cartridge will take, that can't be taken with a 7mm Remington at Walmart prices.

 

[jpndave]

Check it at the 2:50 mark for a sectioned case

I don't see any of the turbo encabulator improvements in that case. The only substantive difference is the case material. No primer retention ring or anything else for that matter. Further, reading that word salad of a patent seems like they are saying all sorts of possible "improvments" are covered by their patent. "We might use brass and we might use steel for the case. We might use brass or steel for the primer. We might make the primer smaller. We might make the primer thicker. We might have a crimp on the primer. Basically if we make it stronger to handle more pressure then that's covered by our patent." What??? In looking somewhat quickly over that patent, the only thing I see that might be and actual patentable idea is the internal crimp ring in the primer pocket. Everything else has been done before. I don't know of an example of the internal primer crimp ring like is shown in some of those drawings but there may have been. The external crimp has been a military mainstay forever. They may also be able to claim the concave primer though none of the advertising I have seen is bragging that up. If the primer gets much tougher/thicker than current primers, rifle manufacturers are going to need to reinvent firing pins too. I would have thought they came up with some new wonder alloy that would handle the stresses of firing and not fatigue. I didn't see a mention of anything like that.

Unless they have something different than has been done in the last 150+yrs of cartridge design then the patent won't hold.

I suspect if Alpha, for example, took their brass and had it tested. The SAAMI pressure for that combination for say the 6.5 Creedmoor small primer could approach that 80k range. What difference in handloading would that be to reloading this steel case other than this has the SAAMI blessing at 80k? The rifles see the same pressure. The barrels see the same. Honestly the lugs would likely see less with the brass case than the steel as it should grab the chamber walls better. Once the case becomes strong enough to handle the pressure the weak point moves to either the bolt lugs or the barrel at ~6'' forward where pressure peaks and it is the thinnest. Or, I guess there could be another weak point in a particular rifle design.

Screen grab of the case cutaway.

 

[AussieWriter]

I don't see any of the turbo encabulator improvements in that case. The only substantive difference is the case material. No primer retention ring or anything else for that matter. Further, reading that word salad of a patent seems like they are saying all sorts of possible "improvments" are covered by their patent. "We might use brass and we might use steel for the case. We might use brass or steel for the primer. We might make the primer smaller. We might make the primer thicker. We might have a crimp on the primer. Basically if we make it stronger to handle more pressure then that's covered by our patent." What??? In looking somewhat quickly over that patent, the only thing I see that might be and actual patentable idea is the internal crimp ring in the primer pocket. Everything else has been done before. I don't know of an example of the internal primer crimp ring like is shown in some of those drawings but there may have been. The external crimp has been a military mainstay forever. They may also be able to claim the concave primer though none of the advertising I have seen is bragging that up. If the primer gets much tougher/thicker than current primers, rifle manufacturers are going to need to reinvent firing pins too. I would have thought they came up with some new wonder alloy that would handle the stresses of firing and not fatigue. I didn't see a mention of anything like that.

Unless they have something different than has been done in the last 150+yrs of cartridge design then the patent won't hold.

I suspect if Alpha, for example, took their brass and had it tested. The SAAMI pressure for that combination for say the 6.5 Creedmoor small primer could approach that 80k range. What difference in handloading would that be to reloading this steel case other than this has the SAAMI blessing at 80k? The rifles see the same pressure. The barrels see the same. Honestly the lugs would likely see less with the brass case than the steel as it should grab the chamber walls better. Once the case becomes strong enough to handle the pressure the weak point moves to either the bolt lugs or the barrel at ~6'' forward where pressure peaks and it is the thinnest. Or, I guess there could be another weak point in a particular rifle design.

Screen grab of the case cutaway.
View attachment 634191

That pic is not representative of the jargon and design options within the patent.
I'm done wasting time with this.