Phil3 said:
My Howa 223 action/barrel has a hammer forged barrel. I read some place that BenchRest shooters wouldn't touch these due to perceived stresses from the hammer forging that could never be adequately relieved. True? Are there any inherent pros or cons to a barrel made through hammer forging?
http://www.youtube.com/watch?v=aCMzyNHkjpk - Interesting video on the process.
Phil
1) hammer forging is the most expensive technology because worldwide there is only one manufacturer of hammer forging machines and price start at 1,3 Mio €. The cheapest method is button rifling.
2) hammer forging is the most accurate manufacturing method. In serial production it`s no problem to hold a tolerance in diameter within 0,01mm = 0,000394". It`s also possible to make the barrel inside diameter conical by controlling the hammer force - for example 0,01mm lower diameter at the muzzle, to rise accuracy
3) Stress in the material can be removed by stress relief heat threatment after hammer forging and after contouring
4) When contouring a hammer forged barrel, the inner diameter is not changing / not rising compared to button rifled barrels. That safe a lot of lapping time because the inner diameter of button rifled barrels will rise at the muzzle when turning thinn contours
Nearly every big firearms manufacture use hammer forging to make barrels: Remington, Ruger, SigArms, Sauer+Sohn, Steyr, HecklerKoch, Glock, Beretta, Heym, Ferlach, Baikal.....
But i`ve never find a company who has a tool to make 6mm barrels with 14" twist and perhaps thats the reason why hammer forged barrels are not used for bench rest.
I have learned, that nearly every barrel can shoot right when he is made right and stress reliefed.