It's my opinion that if any firearm discharges without anyone "touching the trigger", the gunmaker is at fault, not the user. Your experience while hunting with your rifle in terms of inclement weather and lack of an immediate cleaning regiment is not that unusual. The gun should never have fired without someone pulling the trigger. If that was the case, every shotgun I ever used in a duck blind following sleet, mud gale force wind and the Lab shaking off water from its coat after a retrieve would have had an "accidental discharge" every time without me ever touching the trigger. If you don't pull the trigger, the gun should never fire. Never.
I agree. Shoot enough rounds in all conditions, and with people, you will see negligent discharges.And you will see and experience negligent discharges due to trigger mechanism failure.
The first crop I saw was in Highpower. At the time good two stage AR15 triggers were not on the market and competitors had their GI hammers and sears stoned for crisp, final releases. Unfortunately the metal on sears and triggers is actually quite soft, these surfaces would wear due to the spring tension and lever angles of a GI mechanisms, and then these AR15's would double during the rapid fire sequences. The
Milazzo-Krieger was an early two stage design. Great trigger pull until the screw in the mechanism backed out and the rifle would double. And it would always happen in time, whatever locktite was used to hold the screw in place would eventually fail. Even the M1a had doubles due to trigger jobs which reduced sear surface engagement.
Bolt gunners also set their triggers to pulls less than a pound. Their risk was sear following. Ultra light over ride triggers are prone to following, that is an impact on the sear, by the cocking piece, would jar the mechanism so much that the sear would drop. This is a typical over ride trigger mechanism.
M70 over ride trigger mechanism
It is nothing more than a trap door mechanism. Kick out the prop, the door drops. Here, the prop maybe has thousandths of an inch engagement. I believe a hard hit on the sear causes the trigger to move out of the way. Regardless of what is going on inside that mouse trap, I have seen cocking piece follow, and experienced it. Luckily the cam down on bolt guns is slight enough that I have not, nor seen, a round discharge when the firing pin/cocking piece on a rifle goes all the way forward. I am sure there is a dent on the primer though!
this is different.
this mechanism is the BSA version of a Martini action. The Brits created a heinously expensive, rigid, trigger housing. For the era, the trigger pull was light. I think it can be gotten to around a pound.
having such a rigid platform allowed very precise alignments of springs, sears, hammers, etc. However, when this mechanism jars off, it goes bang! When ever I set up one of these BSA rifles for match competition, I monkey around with the two settings the designers created: trigger pull weight and sear engagement. I slam the mechanism closed to see if the thing will jar off. Then I go to the match, and find, it is jarring off at the range! So out come the allen wrenches and I increase the sear engagement just below the creep level, and if if still jars off, add some trigger weight. It is strictly a trial and error procedure, put a round in chamber, slam the breech block into battery, the round goes off, grass gets blown up in the air when the bullet impacts about 25 yards out! Monkey around with the adjustment screws, and repeat. Luckily the breech block is always in battery when the firing pin follows.
I learned long ago not to trust sear blocking safeties. The good military military safeties positively cam the firing pin back, and mechanically lock it back. Only breakage of the firing pin body will cause a discharge. I have had M1903 and M1917 firing pins break, so don't think it can't happen.
Had this happen on a pre 64 M70. The sear nose broke.
Don't remember if there was a round in the chamber when that happened or not. Due to the distance the firing pin can go forward, something like that could cause a primer to ignite.
Here is a good simple design. Pull back on the ring, turn it to the clockwise 90 degrees, drop it in the notch, and the rifle is on safe.
this is one of the best semi auto military trigger mechanisms ever designed, the Garand
same basic mechanism for the M14
when the safety is on, that fin looking piece of metal, visible top picture, engages a cam surface on the hammer, pulls it back, and positively locks the hammer into position.
Shoot enough rounds through a 1911 and you will have hammer following. That half cock mechanism works maybe 50% of the time to prevent a double. But the sucker will still double. I am on the third hammer and second sear on my Kimber Clackamus.
The thing is, Cult Cocked and Locked have created stories to justify their favorite mode of carry: Condition One, round in the chamber, hammer back, thumb safety on. One claim I read all the time is that the thumb safety positively blocks the hammer. This is wishful thinking: it does not. The thumb safety is a sear blocking safety.
Picture stolen from this post:
1911 & M1903 Colt Pistols - Safety and Design
If the sear breaks, if the sear surfaces are worn, if the sear jars off, the hammer will go forward regardless of whether the safety is on!
For those carrying cocked and locked, the only thing preventing a hole in your butt, is that small sear engagement between sear and hammer.
Half cocks get worn, and the spring tension on the sear may not force it into the half cock if the hammer follows
not much of a half cock on the series 80 Hammer.
Of course that firing pin safety on a series 80 never fails, does it?
