90* cocking pieces?

[Pete Wass]

Why aren't 90* cocking pieces and trigger levers commonly used?

Thanks,

 

[jackieschmidt]

I suppose the theory would be that a 90 degree cocking piece would not push the back of the bolt up and unload the top locking lug.

The Bat Neuvo action addresses this in its horizontal lugs in battery. So instead of unloading one lug, it unloads about 50 percent of two lugs.

I have three Neuvo Actions. I cannot say that they shoot any better, or worse, than my Farley’s.

 

[Alex Wheeler]

The 29 degree top lever drops to allow the cocking piece to travel forward. A 90 degree would require the top lever to rotate. It would just be a different design. Most likely the reason it has not been done is that you would have to also convince all the action makers to play along. A trigger with out a compatible action is a non starter. The other question is, is it better? On a conventional 2 lug both lugs are seated really fast. Does that induce some extra vibrations? I think is does, but that depends on how straight the action is and how much bolt clearance. I dont worry so much about the lug seating into the action. The real vibration comes from the back of the bolt slapping the id of the action bore. To limit that effect you want a really square action. If its not, it the bolt body will always slap the inside of the action and you tell the bad ones because you can see the bolt flute pattern in the action body. Thats why really good lug contact is so important to me. Not just contact but also not influencing the back of the bolt into the body. Figure that when the top lug seats is only going a .0001 or .0002, the back of the bolt is going to move 10 to 20 times as far and at much higher speed.

 

[Fast14riot]

Neutral to positive sear engagement angles will always feel heavy, like an AR trigger.

 

[Will Henry]

I do think the 90 degree contact, between the cocking piece and sear, may be a little better but there are a lot of other factors in the design of one. As an aside, if you want a system which absolutely does not influence the attitude of the bolt, look at Savage.
Anyway, the 90 degree contact does not force the rear of the bolt up when it is cocked, but it still deflects the bolt upward as the sear is overridden; unless there is no return spring at all.
An example of a rifle which has been done both ways is the Winchester Model 70. The original trigger was one of the first of the overriding sear triggers. It was replaced by the MOA trigger, which is of the vertical contact, pivoting at the rear type. Both triggers work well. Rifles with either one shoot very well.
Ultimately, when we see rifles shooting 1/8 MOA or less, using an angled contact surface, it is plain that it isn't that much of an impediment. WH.

 

[mike mccormick]

Mauser actions use a 90* cocking piece. Howa does too IIRC, as does the cz 557

 

[gme]

90 degree cocking piece/trigger top lever is common, just not in anything based on a Remington 700

 

[Tad_Earhart]

The Vudoo/Flavio 90 degree trigger is on the 700 pattern. Does require the cocking piece change to 90 degree but the trigger works very well. It is not a rear pivot design but a rotating/slotted top bar. I only have experience with one of these but it did help with measured ignition consistency over a well worked Jewel. The trigger has been running flawless so far for about a year and a half.

Tad

 

[gunsandgunsmithing]

I'm not sure these vibrations hurt anything but there are ways of mitigating bolt rotation as well as how much it drops and what it drops against. Overall, I think these things are a solution looking for a problem but it can be done.

 

[Pete Wass]

Thanks everyone.

Pete

 

[ronemus]

I have a prone gun built on a pre-WWII Oberndorf '98 that my father brought back as a souvenir after serving in Europe during the war. It now has a CG Xtreme trigger and a SpeedLoc firing pin still with 90* engagement; it will easily shoot under 1/2 MOA with nearly all of my reloads. 90* triggers and sears are not an impediment to accuracy.

The SpeedLoc pin made a huge improvement in lock time - the factory pin is HEAVY and takes a while to get moving even with a strong spring. I originally built it with a Canjar single-set trigger (much better than the factory set trigger), but the CG Xtreme 2-stage is far better as are most modern accuracy triggers.

I had thought of getting the bolt bushed (original factory bolt and raceway) but left it alone after checking bolt lug engagement; it was better than 90% due to polishing from use. I don't fix what isn't broken.