GTA
Airguns by Make and Model => Vintage Air Gun Gate => Topic started by: jackssmirkingrevenge on July 06, 2022, 01:03:25 AM
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Herewith my addition to the unusual vintage airgun stable, the Benjamin 30/30. This particular example was purchased as "unrepairable" but is in quite fine condition and appears to be complete:
(http://i.imgur.com/K2Y10mYh.jpg)
Internal diagram showing the unconventional mechanism. The barrel assembly is pushed forward against a spring and held by the trigger. A BB from the ammunition tube can fall into the breech and is held in place by a magnet. When the trigger is pulled, the barrel assembly moves towards the rear, picks up a BB and then knocks the valve open, firing the BB.
(http://i.imgur.com/ShJR9nch.jpg)
Breech detail:
(http://i.imgur.com/5FVFW7Kh.jpg)
Breech with stock removed:
(http://i.imgur.com/T18W5Zvh.jpg)
Barrel and action disassembly:
(http://i.imgur.com/nf8SCR2h.jpg)
Internal parts detail:
(http://i.imgur.com/hOBRetXh.jpg)
Barrel and breech assembled, note the cocking bolt accompanied by a smaller bolt on a slip ring that serves as the safety:
(http://i.imgur.com/K9WYFHxh.jpg)
The plan for this one is to turn it up to eleven, basically make an HPA chamber with a greater volume and that can take higher pressure, and a balanced valve in order to be able to use the original hammer mechanism at greater pressure.
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Heard of them but did not know about using a barrel for the hammer. Nice write up.
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I received a 30/30 from my father years ago, along with a supply of carts.
He referred to it as his "fun gun."
It is that....
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I remember the ads for these showing it penetrating BOTH sides of a steel 5 gallon can with a steel BB.
That was a lot of Zip in the 60's.
Gary
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They're a ton of fun, but only get about 12 full power shots from the little 8 gram cartridges. Mine was chronied in the mid 600 fps range after the wrong seals were potato chipped and keeping it under 400. I can't vouch for the steel pail test, but it cuts right through a big tin can with a little tin can inside it.
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I remember the ads for these showing it penetrating BOTH sides of a steel 5 gallon can with a steel BB.
Here is one of them:
(https://i.imgur.com/KeU2hHp.jpg)
A lot of "zip" in the 60s but it's 2022 and I'm sure we can do a little better than the 700-odd fps these things were doing :)
In that regard, here is a tentative sketch of what a balanced valve and pneumatic chamber might look like, though I'm not entirely happy with it:
(https://i.imgur.com/xwIugWT.jpg)
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That's some fascinating engineering. I remember seeing the ad. Was it in Popular Mechanics?
Looking forward to seeing how the modifications work out.
J~
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Thats the ad. Thanks Jack.
I would not have been able to afford to shoot much at 12 or so shots from one cartridge.
Gary
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Most of the $30-50 co2 bb pistols, like Crosman C11, use the barrel as the hammer.
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Finally found some time to think about this and this is roughly the design I'll be working on:
(https://i.imgur.com/lTrSFY0.jpg)
The balanced valve should drop the force keeping it shut to about one third of the original, so that should allow the chamber pressure to be bumped up to 2000 psi+ while keeping the original firing mechanism unaltered.
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Yes I found these Benjamin 30-30 BB air guns fun to shoot. I have every part for these 30-30 except the barrel , barrel housing and stock to sell. I even had the CO2 retainer 30324 made for stock 8 gram and 12 CO2 cartridges.