Interesting bolt action

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SprayAndPray

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This looks fun. Seems like they have done some overpressure testing.
Anyone wanna translate? http://www.lima-wiederladetechnik.de/Waffen/Heym_SR30.htm

10700-bar-2.jpg


Really nice looking rifles those. I think its a straight pull.
More pics http://www.frankonia.de/shop/Modell.../212595/tf/landscape/vs/1/productdetail.html#
 
I remember reading about these a while back. It uses ball bearings as the locking mechanisms, apparently. Suppose to lend itself to caliber conversion since the locking mechanism doesn't have to fight the bolt face for room, or something like that.

I have this imagine in my head of a crazy, radial version of the locking system from the MG-42.
 
It seems like a very compact solution since you only need a rod with 2 different diameters in there (where it gets smaller it does´nt lock the balls in the outer position). It also seems like a good idea for a straight pull since there is no complicated turning of the bolt while it locks. Ease of construction is high, you would only need to machine in a radius in a pipe and there you go, and the bolt itself you would only need to drill 4 holes (and a light tap on the outside of the holes with some tool so the balls wont fall out while in there).

Strenght, for that bolt to give up the material around the bolt balls (the barrel) would have to expand to, well, a much larger diameter, or the bolt itself (or the rod inside pushing the balls out) would have to be compressed to much smaller diameter (yeah right), I think this is a smart idea.
 
interesting design. i don't think it will ever catch on though, as good ideas sometimes fall by the wayside because of traditionalists.
 
Heym SR30 described thusly at NECG:

"Straight pull bolt with expanding ball bearings lock into receiver ring. The bolt is operated by a horizontal pivoting bolt handle. Bolt operation is very smooth and quick. When closing the bolt it comes to a first stop, is locked but the firing pin is not cocked. Pushing the bolt handle forward to its final stop cocks the firing mechanism. Now the rifle is ready to shoot. To uncock the rifle, pull the bolt handle back to the first stop. For a quick second shot you override the first stop, pushing the handle all the way forward. This locking feature guarantees that no unintended opening or firing can happen. You can't fire the rifle unless the bolt handle is pushed all the way forward."

The decocking gimmick instead of a safety catch is popular in German rifles, seen in various forms from Heym, Blaser, and Kreighoff. Maybe something in their game laws.

The SR30 is a $3000-$4000 rifle in the USA.

Feelthy peechures at
http://www.heymusa.com/heym_bolt_action_sr30.htm
 
I see wear issues. And with wear I see it self-converting to a roller-delayed blowback design (ball-bearing-delayed blowback, I guess). Maybe there is some feature that prevents that, but it isn't obvious to me. The original roller-delay mechanism evolved from experimenting with roller locking on the recoil-operated MGs.

It's neat, but I'll stick with more conventional designs.
 
English versions of some of the rifle related articles here: http://www.lima-wiederladetechnik.de/Englisch/English_Rifle_Articles.htm

Interesting design on the locking mechanism. Some advantages are obvious, but there are some disadvantages too.

1) They are removing a lot of metal from the bolt head to make the holes for the ball bearings.

2) Each ball bearing hole had better be perfect- any scratch or burr from machining the hole is going to be a stress riser, and that area is under some significant stress.

3) To make the bolt stronger, the cross section has to be increased. A Mauser design bolt has truly massive locking lugs on a relatively small bolt body. The ball bearing design has small locking lugs on a large bolt body.

It's cool, but I don't know if it will be around in 110 years like the Mauser action. BSW
 
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