GTA
All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Topic started by: daved on December 25, 2010, 01:58:09 AM
-
Well, I finally got around to taking some pics of the Gamo 890 I've been working on. I've had this rifle for awhile, and got it with the intention of doing some fairly radical work on it :-). I started by doing a tune, after a couple of iterations, I've got it shooting in the high 800's, I expect that to improve with break in and some serious pellet testing. But I'm sure no one considers a tune up "radical" :-). I also did a fair amount of work on the stock trigger, I wanted to see what could be done with it. It's now a very respectable single stage trigger that breaks at a crisp, consistent 1.5 pounds. Still, not radical. Well, does chopping the barrel to 12" qualify? Here's what it looked like when I started:
(http://i185.photobucket.com/albums/x226/daved20319/Air%20Guns/HUNTER-890-1036-z1.jpg)
Yes, I stole that pic from somewhere, but if you've seen one stock 890, you've seen them all :-). This is what it looks like now:
(http://i185.photobucket.com/albums/x226/daved20319/Machining/Gamos-011.jpg)
Stock length on the 890 is about 45", mine is now 40.5". Makes a big difference in the balance and handling. Since 12" is really too short for comfortable cocking, I threaded the end of the barrel 1/2"-20, then made a sleeve and extended nut to hold it in place. Here's what it looks like with the sleeve removed:
(http://i185.photobucket.com/albums/x226/daved20319/Machining/Gamos-003.jpg)
And a more close up shot:
(http://i185.photobucket.com/albums/x226/daved20319/Machining/Gamos-005.jpg)
And here's a detail shot of the extended nut and barrel threads:
(http://i185.photobucket.com/albums/x226/daved20319/Machining/Gamos-007.jpg)
And of course, having chopped and threaded it, the barrel needed to be recrowned, here's another detail of that:
(http://i185.photobucket.com/albums/x226/daved20319/Machining/Gamos-010.jpg)
I'm still not finished with this project. Next step will be an anodizing tank, I've got everything I need, I just haven't made the time to set it up. Been too preoccupied working on my other Gamo, a CFX, but that's a subject for a separate thread :-).
I find I enjoy doing barrel work, this isn't my first, and based on the results I've gotten so far, I'm pretty good at it, even if I do say so myself :-). I haven't had much trigger time with this one so far, but what little I've had looks promising. All in all, this has been a fun project, and I'm really liking the results. After the metal work is done, I think I'll be tackling the stock next. The wood looks fairly decent, but I don't like the color or look of the finish. A little recontouring, some checkering, a deeper brown to the stain color, and a little more gloss, say a satin vs. its current matte, and I'll be happier.
Anyway, this is some of what I've been up to, I'll post more when I get the sleeve anodized. Later.
Dave
-
great work, keep us posted
-
That's looking great! I really like what you've done with the barrel. I might have to "borrow" some of your ideas. ;D ;D ;D
One quick question: Did you remove the barrel from the breech block in order to machine the 1/2-20 threads?
-
Excellent work (or play) Dave. :)
Made one fine looking carbine there. Hope it shoots as well as it looks. Keep us posted. And waiting to see the CFX project too.
Happy Shooting....and modding!!!!
Dave
8)
-
Very nice Dave!
-
That's looking great! I really like what you've done with the barrel. I might have to "borrow" some of your ideas. ;D ;D ;D
One quick question: Did you remove the barrel from the breech block in order to machine the 1/2-20 threads?
Borrow away, I'm sure nothing I've done so far is original :-). No, I didn't remove the barrel from the breech block, my lathe has JUST enough room through the headstock (1 9/16") for the barrel with breech block attached. Just one more thing that makes me happy the brand new lathe I wanted was back ordered :-). Later, and Merry Christmas!
Dave
-
WOW!! :o
-
you should get a cloth wheel and polish your metal work. maybe with some polishing compound to give a mirror-like surface finish. that would look awesome...and if you didn't like it, you could use some other method (that i know nothing about) to blue or blacken the barrel. it would be super smooth nonetheless...
Joshua A.
-
Very nice work Dave.
I'm assuming that's a 17 cal ?
Paul
-
Nice work, Dave.
Please show us the finished project once you get it done.
Should be really cool.
-
Morning, gents. Joshua, definitely planning on polishing, but no mirror finish on this one, if I keep it, it'll be a truck gun. Come to think of it, someone was looking for a wood stock to replace his synthetic on a S1K, maybe I should see if he wants to trade :-). But once it's polished to a level that matches the rest of the gun, I'll be anodizing the aluminum sleeve black, just need to set up my anodizing tank. Although I've got to admit, I'm starting to see the appeal in the silver guns :-).
Paul, yes, it's a .177, not a fan of .22 springers, medium or magnum powered. Just me, I know lots of folks swear by them.
Thanks, Scott. And don't worry, I'll be showing it off once it's all done. Gotta show off my handiwork somewhere, my wife neither cares nor appreciates what I'm doing :-). Later.
Dave
-
Dang!!!! WOW!!!!!
Please keep us up to date on the project.
And if I could, I would steal your ideas in a heart beat.
But, alas, I have no talent.
Bogey
-
those threads looks pretty good dave! what did you use to crown the muzzle??? looks very clean!
-
Thanks, Michael. The crown was cut with a 90 degree countersink, then polished with a brass screw and regular automotive polishing compound. It seems to work, I made the time to do a little shooting today. Only 10M in my shop, but it was doing well with a surprising variety of pellets. Seems to like heavies, though, the best results were with RWS Super Mags and Barracuda Match, managed 5 shot groups with both that were one ragged hole. Didn't chrony it today, decided to work on my CFX instead. More on that in a different post :-). Later.
Dave
-
90 degree???? you mean a 30 or a 60??? lol
-
Nice work Dave. When you starting production?...:) Thanks for sharing.
-
90 degree???? you mean a 30 or a 60??? lol
Nope, I mean 90 :-). 60 degree is typical for center drills, 82 is the standard for wood screws, 90 degree is typical in metal work. That's included angle, if you stand a 90 degree countersink on its point, each cutting edge would create a 45 degree angle with the surface. Hopefully I got the terminology right, if not, I'm sure someone will correct it :-).
Thanks, Gene. Most of this is learning exercises on my lathe, and as you know, it takes a lot of time to make a little money with machining :-). I'm working my way toward offering some kind of tuning services, but that's still a ways off. I've barely learned enough at this point to know how much I still don't know :-). Besides, I haven't even started lobbying the boss for a mill, yet ;-). Whole new learning curve. Later.
Dave
Dave
-
ahh no you got it right dave lol I was not thinking correctly in included angle :)
stupid brainfart on my behalf :)