Hammer spring and accuracy.

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Emu

Emu

Member
Jan 15, 2020
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Queretaro, Mexico
Well,

We all know that a regulator helps to have a more similar speed on pellets/slugs, shot after shot meanwhile regulated.

I would like to know if the hammer spring always provides the same energy to hit whatever inside the firing mechanism of the rifle.

Anyone knows the answer?

If the answer is no, then the electronic trigger topic, should be re-thinked.

The point I raised on the thread: 

"Time elapsing among pulling the trigger and pellet flying"

 
 
A consistent hammer strike is every bit as important as a consistent pressure. Variations in hammer friction from one trigger pull to the next will wreak havoc on the velocity spread. Be it burrs or surface roughness, incompatible materials that want to gall, viscous lubricants that change properties with temperature, poor fit between hammer and tube causing canting and binding, poor support for the spring that allows it to banana, or sear drag...any of them can be detrimental.
 
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In short mostly they do. You do have to consider ambient temps, oils, dust and dirt with the mechanics the spring is working for and their abilities to repeat their performances as well. Similarly this applies to switches and solenoids with actuators. We don't live in perfect world. Only one with compromises. The only thing constant is change itself.
 
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I was in some discussion a while back , maybe a few years ago with the possibility of using a micro gas ram which we could adjust the ram pressure externally but it eventually ran out of steam with the individual. I didn’t have a lathe at the time or the time for that matter to peruse this any further. Now I don’t know if it would help at all with consistency but it sure would make an infinitely adjustable hammer strike. One of the major challenges would be dealing with the very limited space behind the hammer and another being the ram dimensions having enough force to open a valve. Yet another reason for the use of balanced valves. I don’t think the plateau has been hit yet with any of the mechanically fired PCP guns, there’s always a better mouse trap.
 
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Good points have already been posted concerning lube viscosity and friction. 

I'd like to just give one example of what I consider the most consistent hammer setup I've ever seen on a PCP, and that's the Air Arms S500 series. The hammer is round, and has a hole in the center with a bronze bushing. The hammer then runs on a rail in the action. The spring fits around the rear of the hammer, and uses it as a guide. Very good setup. 

I fitted a regulator to one, and lightened the hammer and it was the most consistent rifle I've ever owned. 
 
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All good points and I like to add the adjustment has a big influence as well, it all boils down to margin of error. At lower end of hammer force the same friction inconsistency represents a much larger margin of error. Example: 1 to 10 is 10% vs 1 to 100 is only 1%. this showcase the necessity to have a balance between hammer force and reg pressure. 


THEN: introduce a transfer port restriction well below the capacity/power level of the reg/hammer combo you will have easy ES of under 10 and SD of 1-2. If a unregulated gun can achieve SD of 2 in the sweet spot range of 1000 psi then a regulated gun shouldn’t have issues with 1-2% deviation. Of course we all are power hungry and install the dual TP and throw the factory tuned TP for each caliber to achieve best consistency into the trash........me included.🤣



example: my irrigation valve is capable of 15 gallons per minutes that’s connected to my drip emitter of 1 gallon a minute. No matter what happens my drip emitter will only let out 1 gpm unless my valve isn’t capable of supplying 1gpm to the emitter.



In another word the TP is the final “regulator”, regulator and hammer is supplying air to it so as long as it is at or above the TP capacity The margin of error/inconsistency from the hammer/reg combo is really not that important. 


Or if installed dual TP to eliminate the restriction and shooting at lower power then don’t expect crazy consistency but a good quality gun with a good/balanced tune should not have more than 2% deviation over all scopes/power. Or 18FPE when shooting @900fps. No need to drive yourself crazy over 2% deviation. 




To OP’s question on difference between mechanical hammer vs eletronic jet, with the right technology there is no comparison because electronic valve/jet can be dial extremely precisely! Far more so than mechanical hammer can possibly achieve! BUT we are talking about large difference in a small percentage of overall number without accounting for projectile weight variation. The POI shift between SD of 1-2 and SD of 3-6 is not really detectable even if all the projectiles are exactly same weight. So yes electronic valve can and will be better but will it make any difference for you? All the Thomas BR guns are still old school last time I checked, it might due to the fact the physical limitation of a TP has 0 margin of error when it comes to consistency.....unless someone drills it bigger.😂
 
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All good points and I like to add the adjustment has a big influence as well, it all boils down to margin of error. At lower end of hammer force the same friction inconsistency represents a much larger margin of error. Example: 1 to 10 is 10% vs 1 to 100 is only 1%. this showcase the necessity to have a balance between hammer force and reg pressure.
Click to expand...

Exactly why I believe is light hammer being pushed forcefully will always be more consistent than a heavy hammer moving slowly, all else being equal. 
 
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