Author Topic: Show us your 13xx guns! (Read 22443 times))

DeutschKSK · « **on:** May 15, 2011, 02:09:17 AM »

Here's some pictures of my creation. No name for it yet. Sure shoots good though! Just need some 30mm rings that are not weaver.

List the mods you have done to it as well.

PC77 from Wallyworld
24" .22 Barrel from Mellon Air
Flow-through bolt & 3/4th handle from Mellon Air
Tippmann Stock Adapter from Mellon Air
Rap 4 stock from Ebay
Steal breach from Crosman
2289 forearm & barrel band from Crosman
AC Flat top internals, trigger spring, power spring, pump arm pin, shroud in 1" diameter from AC custom parts

That's it for the mods. Shes got a SWFA 10x scope.. BSA 30mm rings UTG adapter... UTG 1" tactical ring on the shroud, harris adapter / bipod 6-9BR.

Awesome gun! 10 pumps 14.3 Premier @ 530 FPS. Can pump her 20+ times for more power. I have shot targets out to 80 yards.. no problems. Very pleased.

.22 Varmint · « **Reply #1 on:** May 15, 2011, 03:04:40 AM »

Here's mine; a hunter's and plinker's delight!

-Walnut furniture from RB Grips
-Crosman steel breech
-Mac 1 high flow bolt
-10.25 inch .22 barrel (crowned)
-Barrel band from Blue Fork Design
-BSA 2X20 pistol scope
-More to come! (Flat top setup maybe?)

Andrew

rsterne · « **Reply #2 on:** May 15, 2011, 01:30:41 PM »

A couple of years ago I went on a pumper kick.... The 2289 is very popular in Canada, but I have my PAL so am not restricted to under 500 fps.... It's basically the same as a 1377 but with a 14.5" barrel in .22 cal and a skeleton stock.... so I figure it should be OK to post here.... I spent the first while learning the platform, fitting a Flat-topped Piston and Valve, etc, and playing with springs.... Then I decided that if I used a bigger pump I could use fewer strokes.... I purchased the pump tube and linkage from a Crosman 2100/2200 which has 50% more swept volume.... and the eventual result was a gun I dubbed my "Uber-Pumper"....

The gun has a 24" Crosman .177 barrel and uses a 2289 valve with a sear spring inside and ported for better flow.... but that was actually a waste of time except for velocities over 800 fps in .177.... I settled on a Discovery hammer spring to allow the highest velocities before the valve retained air.... The final version reached 991 fps at 30 pumps with 7.8 gr. JSB Express pellets.... There are a lot of modifications involved in using a 2200 tube, but the obvious external one is the "breech band" which is required to mount the front of the trigger group.... This gun achieves 500 fps at 3 pumps, 800 fps at 10 pumps, 900 fps at 17 pumps, 950 at 21 pumps, and 990 at 30 pumps.... with no retained air.... It is equipped with a Leapers 6 x 32 "Bug Buster" scope and sees most of it's time being used for busting grasshoppers at 2-3 pumps.... where the 3 yards close focus ability of the scope comes in handy.... I have a couple of other pumpers I'll post next....

Bob

rsterne · « **Reply #3 on:** May 15, 2011, 01:51:19 PM »

Since my .177 Uber-Pumper was so successful, I decided to do one in .22 cal.... but that was going to use more air.... I got a pump tube and linkage from a Crosman 1400 which has twice the swept volume of the original 13XX/2289 pump.... I wanted more valve volume, so I made an extension from the back half of another valve....

This required more pumping at low velocities, but was capable of more power than a stock valve at the top end.... When I fitted this valve into my .177 Uber-Pumper I actually got it to break Mach.... In the .22 version, it would send 14.3 gr. JSB Express pellets downrange at 890 fps before it began to retain air.... that's over 25 FPE from a Crosman pumper....

Getting that kind of performance comes at a price.... The 1400 pump requires effort at anything over 10 pumps.... which gives 750 fps.... The gun is extremely difficult to pump by the time you get to pump # 20 which is what it takes to get that 25 FPE.... It was a cool experiment, and I learned a lot.... but not very practical.... and I sold the gun not long after completion.... What evolved from it, though.... is in the next post....

Bob

rsterne · « **Reply #4 on:** May 15, 2011, 02:15:05 PM »

Using what I had learned from my Uber-Pumpers.... and living in Grouse country.... I decided to do an Uber-Carbine.... It looks very similar to a 2289, the main difference being the 2200 pump to reduce the number of strokes....

Most of the changes are on the inside.... Here are the parts I made....

The 2200 tube needs some changes to allow the valve to be moved back.... The valve itself needed a flat and a set-screw to accomodate that as well.... The F-T-P and flat valve face are pretty normal stuff.... as are the improved pivot pin and front pivot plug/barrel band.... The breech band required to retain the trigger group is on the bottom left.... In the photo below you can see the bottom side of the 2200 tube and the trigger groups, drilled for the band....

This gun is capable of over 750 fps at 22 pumps with 14.3 gr. JSB Express pellets, using a Disco hammer spring with the RVA wound in almost to coil bind.... I was interested in seeing if I could get two shots at a bit lower velocity, however, by using retained air.... By carefully balancing the hammer spring preload and the number of pumps, I was able to get the gun to deliver a single shot of 600 fps with 10 pumps.... or TWO shots at that velocity with 19 pumps.... The advantages of a backup shot without repumping for Grouse hunting are obvious.... Here are the performance curves....

Note how much difference the Disco spring made to the maximum number of pumps before retained air compared to the 2289 spring.... effectively double.... and another 100 fps.... Also note that I could also have tuned the gun for two shots at about 670 fps and 30 pumps.... or a single shot of the same velocity at 14 pumps.... had I decided I needed more power.... As it is, 11.4 FPE at the muzzle..... and 8 FPE remaining at 35 yards.... is plenty for the type of Grouse hunting I do.... and man, did I ever learn a lot about pumpers....

Bob

VINNY · « **Reply #5 on:** May 15, 2011, 02:53:49 PM »

Very nice, Gentlemen.

airgunandy · « **Reply #6 on:** May 15, 2011, 03:41:03 PM »

OK, here's mine...
An early phase 1 with the old style pistol grip and breach

My latest rifle conversion

A carbine I built awhile back

Jay · « **Reply #7 on:** May 15, 2011, 04:04:23 PM »

Bob(rsterne) can you share info on how you raised the comb on your 1399 stock? Is it adjustable or a cut an rod deal? Sure alot of P-rod owners would like to know.

hoffy43 · « **Reply #8 on:** May 15, 2011, 04:29:15 PM »

Impressive stuff guys.

rsterne · « **Reply #9 on:** May 15, 2011, 04:39:39 PM »

I shortened the stock as well as raised the comb.... and nothing is adjustable.... The risers are 3/8" OD Carbon tubing.... If you look closely at the bottom of the stock just in front of the butt, you will see a join where I shortened it.... I dowelled that together and glued it.... Basicallly I just drilled 3/8" holes, ground grooves where appropriate (in the butt piece) and glued it all together with JB Weld epoxy.... I presume you could use aluminum tubing, or even blued steel, as JB Weld stick to pretty much anything....

Bob

Jay · « **Reply #10 on:** May 15, 2011, 05:07:59 PM »

Thanks Bob,never noticed till you pointed it out that you had shortened it(nice job). GREAT LOOKING GUNS EVERYONE keep them coming!!!

Madkoifish · « **Reply #11 on:** May 15, 2011, 07:17:58 PM »

rsterne>>

Is that band something you had to mill specifically or is it a re appropriated part? I am interested in building something similar minimize pumps, mostly for low fps plinking.

rsterne · « **Reply #12 on:** May 15, 2011, 08:17:41 PM »

It is an original design and I machined it myself.... HOWEVER, I gave the drawings to a machinist in Ontario, Canada who produces them.... He goes by "DerekVinyard" on the Canadian Airgun Forum and his name is Michael.... He also carries the Trakar 0.040" wire hammer springs (stiffer than a Disco spring).... Great guy to deal with....

Bob

Madkoifish · « **Reply #13 on:** May 15, 2011, 09:31:37 PM »

I take it it was required since the valve was not in the same location to use the forward screw? Think I will have to read up some on this sort of mod so I know what is going on with the tube and internals

For the heck of it my gun fairly stock with some internal goofing around and a steel breech while I wait for shipments. Replaced and messed with the sear spring flattened out all contact surfaces inside too. Replaced all the ext hardware except the breech screws.

update on the gun

rsterne · « **Reply #14 on:** May 15, 2011, 09:37:52 PM »

Correct.... IIRC, the 2200 tube does not have a hole for the trigger group/valve screw anyway.... I machined the front of the valve off just behind the original mounting hole anyway.... and then I moved the valve back to increase the pump stroke.... The original 2200 valve is a tiny thing.... If you need dimensions, PM me.... I think I still have my drawings kicking around....

Bob