Old .177 pellet (slug) Gun

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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Sun Oct 21, 2007 3:23 am

Here a some lousy pics of the rifle.
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When i first fired it the slug got stuck about 6mm away from the end of the barrel. Imagine this was from all the oil JSR :oops:
My old man is an ex armourer (3rd RAR) and has fixed anything from a Pack Howitzer to a pistol, HE IS THE ON THAT TOLD ME TO SOAK THE LEATHER PISTON IN OIL ! Just goes to show that you learn something everyday!

After now i'm sure it can salvaged, :D I will start my mission in earnest!
It is grouping at about an half an inch at 15 feet now, can that be improved?
I'm thinking new spring and piston, should i make my own piston or go with the orginal?
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jackssmirkingrevenge
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Sun Oct 21, 2007 3:54 am

The finish looks quite good for its age :)
When i first fired it the slug got stuck about 6mm away from the end of the barrel
That's possibly due to rust inside the barrel, run a white patch through to check. A couple of oil-soaked patches through the barrel should alleviate the problem. Also check the breech seal where the barrel meets the breech, if there's a leak these you lose power on firing.

Oil in the compression chamber will cause dieseling on firing, which causes wear to the seals and in extreme cases could also distort the chamber itself.
It is grouping at about an half an inch at 15 feet now
For a medium powered springer of that age, I don't think it will get much better. 0.5" at 35 yards is about the best this sort of rifle will do on a windless day.
should i make my own piston or go with the orginal?
Be mindful of the weight, there is an optimum weight for a given spring power and pellet weight. Being too heavy or too light will have a significant effect on power and smoothness.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Sun Oct 21, 2007 4:02 am

I understand the "Diesling concept" that you mention it.
The breech seal was rooted and all i had was an ill fitting o ring. I made a spacer to go under the ring because it was not sitting proud of the surface.
Are there special seal materials? The barrel is not aligned with the chamber on the vertical, loose breech i think. Would slightly bigger screws fix it?, or would i have to modify the actual mounts?
Thanx :)
America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
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jackssmirkingrevenge
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Sun Oct 21, 2007 6:09 am

If worst comes to the worst you can always buy an original breech seal from the site I linked you to.
Are there special seal materials?
Usually made out of Nylon 66 or PTFE though really there's nothing wrong with leather ;)
The barrel is not aligned with the chamber on the vertical, loose breech i think.
A common problem with older break barrel rifles, it it loose because of wear or poor manufacture?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Mon Oct 22, 2007 4:24 am

I'll make a seal from Nylon, it should help the shootin up thing too.
America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
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mtronic
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Tue Oct 30, 2007 7:26 pm

hey nova thats a nice piece especially for its vintage :)
If you need sights why not check your local smithy?

Is it just me or is the barrel shorter that modern air rifles? I haven't used mine in ages, its locked up in my dads gun cabinet.....its a gamo expo 26 :oops: dont hate me jsr it was a 11th birthday present so its comming up to its 10th year so I think I'll sell it soon. Or take it apart and make a high power pneumatic :twisted:
Always out numbered....
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Tue Oct 30, 2007 7:32 pm

I'm not sure about the barrel- could well be shorter than a modern version becuase they can get more power out of them now, maybe.

Edit: (off topic) JSR, i have finished my hp pneumo :D Pics after work
America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
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mtronic
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Tue Oct 30, 2007 7:55 pm

yeh the first pic makes the barrel like kind of stubby but maybe I'm just imagening it but I would have thought the barrel on mine to bit a bit longer, maybe like 2"?

Anyway good luck with it, I know how preicious heirlooms are to people I have an old Marlin No. 29 pump action .22 rim fire circa 1889 that been in our family for ever.
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Tue Oct 30, 2007 11:31 pm

Unlike pneumatics, with springers longer barrel doesn't necessarily mean better velocity. Usually a longer barrel is there to give more cocking leverage, I know people who've had their barrels cut down and who saw a slight increase in power.
its a gamo expo 26
nooooooo! hehe but seriously, I have nothing against Gamo, they do make popular rifles that can be accurate - but compared to proper German or British springers, their finish tends to be lower quality, their designs use a lot of plastic parts and the triggers tend to feel a little - well, agricultutral.
JSR, i have finished my hp pneumo
w00t! how well does it work?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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