Originally Posted by
WV Hunter
I thought it was more along the lines of the savage patent deal than an injury issue.
You're correct - Savage does hold the patent for the removable vent liner in a breech plug. So in this case while Knight, Lehigh, and almost everyone else has a concern about safety the reason for the brazing was concern of a law suit about crossing the lines of a patent.
The only reason I can think of that they went forward with the brazed vent liner is that the vent liner should/could outlast a plug with out a vent liner. The heat created by BH has shown that this is not the case. On the other hand I am shooting T7 and so far have been getting longer life from the vent liner than I might have gotten from a solid breech plug.
The original Lehigh breech plug was built and hardened from 17-4PH metal.
17-4 PH Stainless Steel is a precipitation hardening martensitic stainless steel. Typical usage is seen in applications requiring high strength and a modest level of corrosion resistance. Strength and toughness desired can be manipulated by temperate range in the heat treatment process.
It is an extremely strong metal. But because of the necessity to make the vent liner non-removalable the metals of both the breech plug and the vent liner were changed so that the brazing process could/would work. The breech plug was changed to 416 Stainless. With this new combinations of metals the brazing process could be completed with a normal vacuum suction method.
None of this process would have been necessary if Savage was not the owner of the patent or if Knight could have received assurance from Savage that patent violations would not be filed.
Today if you were to go the Lehigh Bullets web site (not Lehigh Defense) the Savage Vent liners now being offered have returned to the type that Lehigh originally produced for the Savage and with the higher level of hardening applied.
At this point, and I have not asked, if Lehigh will ever be able to offer the original Lehigh bare breech plug.