This is amazing, and more complex than many guns posted here daily!
I am likeing that loading mechanisim and something similar may find it's way into one of my future guns!
I had to post this after hering that it used up to 800psi.
Posted: Mon Feb 21, 2011 1:37 am
by MRR
Actually this is a very known air rifle here on the forum.
Use the search and you will find lots of pages that reference the Girandoni, including schematics.
Posted: Mon Feb 21, 2011 4:01 am
by Crna Legija
does anyone how if the breach had a seal in it or was it just a good fit? im also thining it would make a nice loading mech.
The Girandoni system - upper two images show tubular ball magazine on right side of gun, distinctive loading block traversing the receiver. Note that receiver casting is a single top piece. Again notice the smooth transition in lines between the receiver and the air reservoir in this authentic specimen. Lower image shows the sliding loading bar with its ball socket and with the right hand retaining screw removed. These loading bars were tapered so precisely that, before the magazine spring was added during reassembly, the bar would slide into an airtight battery position by its own weight!
I had made an animation of the valve mechanism:
Posted: Mon Feb 21, 2011 5:59 am
by Insomniac
I can't really tell from the animation... But is there anything physically stopping one from pushing the hammer forwards by accident and inadvertantly venting the entire pressure chamber?
Posted: Mon Feb 21, 2011 6:08 am
by jackssmirkingrevenge
Insomniac wrote:is there anything physically stopping one from pushing the hammer forwards by accident and inadvertantly venting the entire pressure chamber?
You mean other than air pressure? The valve seat is around 0.4 inch diameter, so even if the chamber is just at 100 psi you need over 12 lbs of force to open the valve.
Posted: Thu Feb 24, 2011 2:27 pm
by Brian the brain
The orange/light brown part is what pushes the valve open.It is engaged by the hammer, wich is in turned locked by the trigger mechanism.Upon firing the hammer is released, pushing the orange part, thus opening the valve.
When the orange part is pushed in far enough it disengages from the valve-rod and the valve closes eventhough the orangepart is at its end position.
Recocking the hammer will re-align the orange part and the cycle can be repeated.
I'm somehow unable to open that last link but the 1940's " partisan airgun" deserves a spot in this topic as well.
It is a direct dessendant (?) of the Girandoni guns, the only major difference is the spring in the mag, while the Girandoni was gravity fed...as long as the barrel was pointing up...
The rest works the same way, but configured like an over-under.
Posted: Tue Mar 01, 2011 1:54 pm
by jackssmirkingrevenge
Brian the brain wrote:I'm somehow unable to open that last link but the 1940's " partisan airgun" deserves a spot in this topic as well.
I'm curious about how they made such precision guns and high pressure pumps in the 1700's Were they all cast metal? Or hand made?
Posted: Tue Mar 01, 2011 11:07 pm
by jackssmirkingrevenge
Gun Freak wrote:I'm curious about how they made such precision guns and high pressure pumps in the 1700's Were they all cast metal? Or hand made?
Consider first of all that this is not an item that could be found in every home, rather an exquisite luxury item which only the wealthy could afford, before the age of mass production.
I understand there might also be a discrepancy between the US and Europe in the 16th century.
If you want to look at technical ability through the ages, look at clocks and watches
Posted: Wed Mar 02, 2011 8:02 pm
by Gun Freak
jackssmirkingrevenge wrote:If you want to look at technical ability through the ages, look at clocks and watches
Were they all cast metal? Or hand made? 
