Kramer Defence files Patent for Bolt Heads for Cartridges Larger than 6.8mm

[montana]

http://www.thefirearmblog.com/blog/2016/...ld-reacts/

[rwh]

Bad link, found the patent at https://lookaside.fbsbx.com/file/full%20...3PKXdixQnw

The only important part of the patent is the claims at the end. Looks like all they did was patent bolts with outside diameters that are bigger than the standard bolt with a few variations on the dimensions. I don't see how a standard grendel bolt would infringe on their claims. On the other hand I also don't see how taking a working machine and increasing the size of some of the parts wouldn't be obvious to anyone familiar with the state of the art.

The legal fees to file the patent must have been at least $10,000. I doubt they are going to make anything except enemies if they try to enforce this.

[bwaites]

No way that flies. Too much prior art. Colt was making 7.62x39 bolts decades ago. The "Grendel" bolt is actually the Beowulf bolt and that goes back more than a decade before this patent.

Overreach!

[din]

Patent trolls should be boiled in tar.

[LRRPF52]

Yeah, they can start with Colt in the 1980's on a patent claim and see which hand fills up first.

[Bill Alexander]

The patent does not actually appear to have any bearing on Beowulf/Grendel bolts, rather it relates to a bolt and extension with dimensions extended from that of a regular AR15 but still dimensioned to fit within the existing AR15 receiver. It seems pretty specific to a 0.475" rim on such a bolt but with a short cartridge of 2.250" length.

As such it does not overlap the work by Remington or any of the AR10 types.

One wonders if as much effort was extended in developing the weapon and ammunition as writing the patents. While such a bolt/extension is feasible the constraints of the small frame gun does not allow a double stack magazine. Changing the receiver to suit allows a quick sidestep of the patent. Equally the chamber wall thickness of such a design is marginal with an efficient operating pressure and the barrel tennon will be at a limit under the head thrust.

It is relatively easy to significantly increase the strength of the Grendel bolt. In doing so it would be possible to move to a near optimum 58K psi. Albeit we would have to adjust the cases. The constraint is the barrel itself and the threaded connection. Unless correctly redesigned it stretches over time and the barrel is found to be loose. Even as we are now the extension has design changes to limit this effect.