The Heym SR30 is a modern hunting rifle produced in Thuringia, Germany using a rather clever and interesting locking system. It is a straight-pull rifle with six ball bearings around the circumference of the bolt head. When the bolt handle it forward, it forces a central plunger down the interior of the bolt body, forcing the ball bearing out to lock into recesses in the receiver. Pull the bolt handle back, and the plunger retracts, allowing the locking bearing to retract into the bolt so it can open. This avoids the usual problem of straight pull systems having quite stiff actions when a camping system is used to translate linear motion of the bolt handle into rotary motion of the bolt head.
Ian’s Video [7:21]: https://youtu.be/a-44H321Bsg?si=
The Savage Impulse is also a take on this concept of a roller locking straight pull action. Here’s a short and slick promo video they made with an X-ray view of the action [0:15]
You must log in or # to comment.
It’s an interesting design. Not sure how I feel about relying on a QD-style captive ball system to keep a rifle bolt from firing into my face though. I’d imagine you’d have to be pretty vigilant about monitoring the amount of wear on those ball bearings.
I wonder how long they would last with a round like .30-06
It would make sense that they’d fail on the sheer line of the cage.
I’m no Teutonic engineer but I think the idea is probably more durable than you’d guess at first blush. Savage chambers their newer version in .300 WSM, so there must be some merit to the idea.
I’m not saying they wouldn’t be durable. I’m just curious how they fail.
