Gunsmithing Alternative bolt action designs.

[NBLongRanger]

We're all familiar with the standard x lugs up front and/or single rear lug..

The concept has stood for a very long time. I haven't done a massive amount of research but have found 1 newer design(modification really)..It was Buttress thread sectioned radially to allow sliding the bolt in and turn to lock @ 90 degrees vs. screwing it in... Effectively like having 4sets of lugs 1 behind the other on the axis of the bolt.

Just interested in hearing some new concepts of bolt engagement.

 

[Victor N TN]

Re: Alternative bolt action designs.

Look at the breech blocks of WW2 artilery pieces.

 

[NBLongRanger]

Re: Alternative bolt action designs.

Yeh, the dropping slide plate. Or door style plate..

The drop plate would be a pretty easy job to machine up..the slide would have to be Seriously tight or have cam locks to seal the end of the breach though.

 

[rero360]

Re: Alternative bolt action designs.

I seem to recall reading recently about a new bolt design from over in Europe that instead of using lugs to lock up the action it uses bearings, kind of like those key holders that locks and unlocks with the plunger at the end. Its a straight pull bolt also. They claim to have tested to insane pressure testing without any failures but I still don't know how I'd feel about using that design.

 

[WesP]

Re: Alternative bolt action designs.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rero360</div><div class="ubbcode-body">I seem to recall reading recently about a new bolt design from over in Europe that instead of using lugs to lock up the action it uses bearings, kind of like those key holders that locks and unlocks with the plunger at the end. Its a straight pull bolt also. They claim to have tested to insane pressure testing without any failures but I still don't know how I'd feel about using that design. </div></div>

would that be like the roller locking bolt found on most h&k rifles and submachine guns?

 

[NBLongRanger]

Re: Alternative bolt action designs.

Similar yes. That design sacrifices holding power for smooth and fast operation though.

Lugs direct the force axially wereas round bearings are going to induce axial and radial thrust and are going to stretch the ID of the chamber over-time and if the maximum pressure is even approached..

Modified for a bolt-action application I could see finding use-able results.

 

[Greg Langelius *]

Re: Alternative bolt action designs.

Your initial concept appears identical to the existing 'interrupted thread' breech/bolt locking concept.

The roller locking bolt is another existing design.

Some shotguns and the SKS work on a 'tipping bolt' design, where the rear end of the bolt rises into a recess in the receiver to lock up.

Greg

 

[mlthoma]

Re: Alternative bolt action designs.

If I understand your description correctly it sounds like a Weatherby bolt. It has 3 sets of 3 lugs one behind the other and locks with 60 degrees of bolt rotation.

Mike in ABQ