Author Topic: 1325XLT update testing (Read 16691 times))

K.O. · « **Reply #20 on:** February 03, 2014, 10:12:09 PM »

I would hazard that with a 7" stroke and flat top setup your 15 pumps is more like 23-25 pumps of mine.

What size valve you running in that monster?

I am now up to 17.6 fpe or so at 25 pumps so I am only lagging about 4 fpe with an easier to push pellet...

remember my fps is average over 15' so at 25 pumps muzzle fps is close to 630...

Big Bore Bart · « **Reply #21 on:** February 03, 2014, 10:54:22 PM »

It's an 8" stroke into ~1.8cc valve. All ports are .218" equivalent. The 2100 makes ~5-5.5" stroke.

rsterne · « **Reply #22 on:** February 03, 2014, 10:56:58 PM »

BBB, it sounds like your pump is similar in swept volume to a 140/1400?.... My Uber-Pumper .22 cal had 36cc of swept volume, and with an extended valve (about 2x normal 13XX valve volume) I managed 25.8 FPE with 14.3 gr. pellets at 20 pumps which is where it started retaining air.... This was in the days before I understood that heavier pellets generated more FPE, and also the heaviest hammer spring I had was from a 2200.... I often wish I still had that gun to see what it would do with a Disco hammer spring and 21+ gr. pellets....

Bob

K.O. · « **Reply #23 on:** February 03, 2014, 11:06:59 PM »

Quote from: Big Bore Bart on February 03, 2014, 10:54:22 PM

It's an 8" stroke into ~1.8cc valve. All ports are .218" equivalent. The 2100 makes ~5-5.5" stroke.

I measured mine and it is 5"

25 pumps 609 fps
30 pumps 609 fps twice

I would say valve and pump are maxing I am about to see what happens at 21 thru 24 pumps be right back...

K.O. · « **Reply #24 on:** February 03, 2014, 11:08:59 PM »

first it sure is fun when things improve...

Big Bore Bart · « **Reply #25 on:** February 03, 2014, 11:13:04 PM »

Quote from: rsterne on February 03, 2014, 10:56:58 PM

BBB, it sounds like your pump is similar in swept volume to a 140/1400?.... My Uber-Pumper .22 cal had 36cc of swept volume, and with an extended valve (about 2x normal 13XX valve volume) I managed 25.8 FPE with 14.3 gr. pellets at 20 pumps which is where it started retaining air.... This was in the days before I understood that heavier pellets generated more FPE, and also the heaviest hammer spring I had was from a 2200.... I often wish I still had that gun to see what it would do with a Disco hammer spring and 21+ gr. pellets....

Bob

Just slightly more, 39.4cc. I may adopt your breech band concept, and do away with the forward screw, to make a larger check end. That should let me get 2+cc.

You know you want to build another Uber-Pumper.

K.O. · « **Reply #26 on:** February 03, 2014, 11:24:22 PM »

yep he is topping out at 22 pumps...

now for sure it is all the pump/ valve volume can give.

Big Bore Bart · « **Reply #27 on:** February 03, 2014, 11:35:27 PM »

Your pump is maxed, the valve still has room. You're not retaining air yet.

K.O. · « **Reply #28 on:** February 04, 2014, 12:09:43 AM »

hey Bart I think I need to start buttering ya up again...

I think I know how to get .16 ci. but I want to keep this nose as is because I think it has proved itself very close to just right for a 18" .22

at .1256 ci and I do want a 22 version pellets cost about half what these did...

To get .16 nose would need to be .125-.150 from nose to check poppet seat (I would pre fit to cup, this one is .250 to check seat.)

behind check ledge I can open it up to .5 till just before start of threads that leave a wall thickness of .11 in that section (the section you

added for me ) plus like this one the I was able to open the threaded portion to .4 from .36. and the of course same mods to exhaust section

but ported only to .180 for .22

so yep you guessed it I am asking for another valve mod job later this month or maybe next month some time.

I think the .16 valve will get me close to 700 fps and 21 fpe and almost keep up with your monster, but more importantly keep the .25s

trajectory in a half inch kill zone for most of 25 yards.

Bob (rsterne) I wish you had done work on the effect of below optimum valve volumes...

K.O. · « **Reply #29 on:** February 04, 2014, 12:17:23 AM »

I promise it would be the last for quite a while...

to broke for much more and want steel breech for this one...

K.O. · « **Reply #30 on:** February 04, 2014, 12:22:05 AM »

have to go for a couple hrs. I promised to take the neighbor shopping...

thanks for the help and encouragement tinkering is a blast and the sound of the 20g pellet hitting its target

Big Bore Bart · « **Reply #31 on:** February 04, 2014, 12:26:14 AM »

For the steel breech, order from the 2300 series and Disco menus.

I think I can get you even more volume with some careful boring in both halves. Send a PM when ready. Heavy lead at velocity.....

yeah

rsterne · « **Reply #32 on:** February 04, 2014, 12:42:30 AM »

I made a center section and extended the valve.... but you need a breech band to mount the trigger group and a tube without the trigger screw hole....

Bob

Big Bore Bart · « **Reply #33 on:** February 04, 2014, 12:59:20 AM »

K.O. used a "breech band".

He didn't use a forward screw.

K.O. · « **Reply #34 on:** February 04, 2014, 11:34:36 AM »

Hi Bob

When I saw your work that is when I got the idea I could make this work and that if nothing else I could use a co² cart for an

exterior reservoir...

I knew that the .25 bore would require as much valve volume I could get and was inspired by the valve that you show above.

I P.M.ed Bart with the idea and he said the best way would be to take a 760 intake section/nose and make what I wanted from it.

the limiting factor was the 2100b pump tube, there was only room to move the valve back .3" so that is how much longer the valve grew.

I have wanted a .25 pumper since I was about 17 and passed 50 recently so I am very thankful for Barts help

Below is Bart's CRAFTMANSHIP and the Heart of this pumper an extended nose 2100 valve.

K.O. · « **Reply #35 on:** February 04, 2014, 05:52:11 PM »

Today I gave it a 7/16 screw eye front peep and its final test.
All the Fpe in the world does not matter if you can not hit what you are aiming at...

Bottom group was first, 19 pumps offhand,

then the top group, the highest shot was 19 pumps the rest 18, prone no rest

all at 25 measured yards.

Trigger was a bit heavy but only the very last shot was after fixing it is the one under the 19 pump shot.

So yep if I miss its me not it...

K.O. · « **Reply #36 on:** February 04, 2014, 06:33:41 PM »

Just put a Campbell's soup can in a chili can and at 22 yards it went thu all 4 layers...

Cue the mad scientist laugh...

Big Bore Bart · « **Reply #37 on:** February 04, 2014, 08:24:43 PM »

Accuracy looks very good. Double tin can is great, that means nutters and starlings won't know what hit them.

Get SoftChrono working. Let's see what it is really doing.

K.O. · « **Reply #38 on:** February 05, 2014, 03:55:10 PM »

well Bart I connected my old 32 bit machine to the eye-net (Big bro reptile peeps iss watching

) and soft chrono is running fine on it.

It was the one I use anyways.

I just cannot get it to capture a shot yet.

Is there a way to set it up for 2 mics.

I used my Shure sm58 so I know its not the mic.

I will try again tomorrow after doing some more softchrono reading to see what I am doing wrong...

Did some programing in the early 90s you would think I could use software...

It looks to use pretty much the same method as I do... using audacity.

Big Bore Bart · « **Reply #39 on:** February 05, 2014, 04:43:31 PM »

I just use a Radio Shack electret element connected to 18 feet of speaker wire and a 1/8" plug, for my mic. The element was like $6 the speaker wire was $3.5 or so. Works just fine for my purposes.

As far as two mics, it has been done.

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1325XLT update testing

Author Topic: 1325XLT update testing (Read 16691 times))