Author Topic: Did a little more tinkering this weekend (Read 6520 times))

Gertrude · « **on:** July 05, 2015, 04:55:23 PM »

Well after getting the FD-PCP now Bottle fed, and fitting a camera mount,...
My buddy and I completed my "2555 PCP Carbine".

He had finished his"2555" last week, and I was just itching to get mine off the Bulk Co2,... and onto HPA.

I will try to do a little indoor chrony work with them today, and post up some numbers a little later.

Here's a few pics I thought I'd share of the progress so far,
The FD-PCP w/ "Baby Bottle" and Video Cam and Ratting light

and here's a few pics of what we are calling the "2555 PCP Carbine".
(I think this would also be a great little build in both .177 and .22)

I can't wait to get them both out for a round of Testing and Pesting.

No doubt the .25 Carbine will probably have a pretty low shot count,
but what the heck, should still hit pretty hard (at under 30 yds) for a pistol conversion.

MI Yeti · « **Reply #1 on:** July 05, 2015, 05:03:01 PM »

Nice looking conversions ,looking forward to the numbers .

renowntwo · « **Reply #2 on:** July 05, 2015, 07:05:11 PM »

Nicely done.

pneuby · « **Reply #3 on:** July 05, 2015, 07:37:04 PM »

Lovely work on BOTH of those!

Gertrude · « **Reply #4 on:** July 06, 2015, 12:45:19 AM »

OK, so I ran some pellets thru the "2555" Carbine.

If any of the more knowledgeable tuners and number crunchers here would care to evaluate these, and give some feedback on what I could do to flatten these strings a bit more I'd greatly appreciate it.

From my limited knowledge and skills, I'm thinking a starting pressure of 1500ish and a slightly heavier hammer spring would probably help ?

In any event, I'm thinking it's fairly impressive, considering we started off with a Co2 powerd .22 Pistol, and ended up with HPA powered .25 Carbine, that is putting out well over 20 FPE

Here's the numbers it was giving me:

Crosman “2555” .25 cal Carbine
Pellet - JSB Exact King 25.39 gr.

Starting PSI - 1800 1500 1250 1000 (strings ending at approx. 450 PSI)
------------------------------------------------------------------------------------------------

FPS - 429 553 615 655
556 607 638 647
560 616 646 632
563 624 650 610
577 630 655 581
589 640 648 550
596 655 635
605 656 615
613 658 593
623 649 560
631 631
637 612
648 586
653 552
656
653
637
620
593
571

Round Ball 23.6 gr. Starting PSI – 1250 (ending approx. 450 PSI)

614
645
654
653
658
648
629
608
581
550

Yarp · « **Reply #5 on:** July 06, 2015, 10:06:16 AM »

Quote from: pneuby on July 05, 2015, 07:37:04 PM

Lovely work on BOTH of those!

Absolutely.

sshewins · « **Reply #6 on:** July 06, 2015, 04:04:14 PM »

I'm liking lots!

avator · « **Reply #7 on:** July 06, 2015, 05:24:21 PM »

This really sparks my intrest Ron. I sent you a message.
Thanks for sharing.

Bwalton · « **Reply #8 on:** July 06, 2015, 05:33:54 PM »

very nice looking forward to some footage

D-RIG · « **Reply #9 on:** July 06, 2015, 08:14:57 PM »

Now that you have tinkered it's time to shoot something Ron .

Monkeydad1969 · « **Reply #10 on:** July 06, 2015, 11:46:09 PM »

Nice shooters, Ron. So where did you get that gauge adapter on your 2555? I need one for my 2260 .25 carbine ( guess it could be called a 2560).

Joe

Onebaddj · « **Reply #11 on:** July 07, 2015, 01:10:50 AM »

nice set ups and interesting build on the 2555. and very interested about that fill adapter also. Looking to bulk fill and reg my 2400 22 cal. your little adapter would work nicely.

avator · « **Reply #12 on:** July 07, 2015, 04:17:29 PM »

Looks like one of these in .22 is in my very near future.
The guage might be nice but I'll probably go without it.
I fill my FD-PCP guns with the guage on the tank. Never had a problem.
Thanks Ron, for the help.

rsterne · « **Reply #13 on:** July 07, 2015, 05:05:05 PM »

The 1250 psi string is still a bit weak on the first shot.... With the current hammer setting, I would try a 1200 psi fill.... You should get about 6-7 shots within a 4% ES.... If you find a 6% ES acceptable, all you need to do is stay at 1250 and limit yourself to 8 shots.... If you want more power you could try 1500 psi and a heavier hammer spring, but expect even fewer shots....

Bob

Gertrude · « **Reply #14 on:** July 07, 2015, 06:37:29 PM »

Thanks for all the compliments guys,

Joe / DJ, the fill fitting was a little custom job that my buddy machined out for us.
They are not a commercially available part.

But,... for anyone wanting to do a similar build without a gauge, you could use the fill adapter assy from a P-rod, (part # 1700-101)
He also machined from scratch, the back half of the valve assembly for a full flow, but you could get the same thing by using the back half of a P-rod valve, (part # 1700-003), and their valve stem, (part # 1700-140)
The 2260 tube used is (part # 2260-004).

Yeah,
we were basically just doing this for fun of it, and to see how it might turn out with the .25 cal barrels.
We were never expecting a very high shot count, knowing that going full flow on the valve, and pushing a big .25 was going to be one "air gobbling" combonation.

Also, we were not really expecting to see a tight ES either. This build was not about building a super effecient or super long range gun, it was more about just seeing what the initial results would be, and then seeing if we can "tune" it at all.
We will still continue to tinker with it and see what we can come up with.

Since the design of the 2240/50 has no real built in adjustability, all you've really got to work with is the fill pressure and the hammer spring.

I think my next step will be to try shimming the existing spring a little, and run another set of numbers to see what happens to the strings. and/or if necessary, change the spring to a bit heavier one.

My buddy and I discussed possibly using a power adjuster from Crosman, and I think he has ordered that part for us today... so we will see when it gets here, if it is beneficial for fine tuning this build.
(and I know he is also going to be swapping a P-rod trigger assy onto his tonight

(when does the madness stop ?)

I would guess that doing this build in a .22 cal would give a better/(flatter) shot string ? ? ? maybe ? ? ?, ... I dunno.
I may just go ahead and get a barrel from Crosman to try that out for the fun of it.
I do have a .177 Disco barrel.... may have to toss that on tonight just to see what numbers it will produce.

I suppose if we were to machine up another tank block (similar to the one we put on the FD), and then put a regged bottle on, we could get a very low ES and probably a zillion shots too

.

for anyone who might try this build out for themselves, PLEASE REMEMBER THESE ARE LOW Pressure Guns ! ! !
they were intended to be run on Co2 from Crosman, so you should stay within those pressures to maintain the original safety margins.

I DO NOT RECOMMEND TO ANYONE GOING HIGHER THAN THE MANUFACTURERS INTENDED PRESSURE LEVELS,
I did this build for myself, and to simply share with you guys what I was doing.
I do not want anyone getting the idea that this build whould be ok to go to higher pressures.
When you mess around with HPA, you better know what you are doing, or you can get seriously hurt.
DO NOT DO IT !

Tonight I will be playing around with the FD-BB-PCP and the chrony. looking forward to some nice numbers coming out of that !

Hoping I can get it up to somewhere around 950-1000 FPS with 18 gr.
Wish me luck !

Cheers, Ron

SpiralGroove · « **Reply #15 on:** July 07, 2015, 07:32:11 PM »

Hey Ron,
Beautiful work on the "2555 PCP Carbine"

I Gotta try the bi-pod on a QB.
Kirk

avator · « **Reply #16 on:** July 08, 2015, 02:13:10 PM »

I pulled the trigger on my parts order today. I'm building mine on a 2240 with a steel breech. I also have a 24" crosman barrel in .22. So I ordered:
1761-102 Cap Assy. $9.59
1700-101 Fill Valve $16.92
1700-140 Valve Stem $1.72
2260-004 2260 Tube $14.97
1700-003 Valve Cap $8.00
w/ shipping $4.00
Total $55.97
I have the barrel bands, a forearm and a shoulder stock.
I did not opt for the guage. I'll fill from my tank guage like I do my fd-pcp guns.
Thanks again Ron for sharing this build.

UCChris · « **Reply #17 on:** July 08, 2015, 03:54:27 PM »

Ron, do you have a writeup on the FDPCP bottle build? I have a XS60 laying around that I'd like to bottle and regulate down to 1000 or so psi.

Gertrude · « **Reply #18 on:** July 09, 2015, 05:15:05 PM »

Quote from: UCChris on July 08, 2015, 03:54:27 PM

Ron, do you have a writeup on the FDPCP bottle build? I have a XS60 laying around that I'd like to bottle and regulate down to 1000 or so psi.

Hi Chris,
No I did not do a build thread for the Bottled FD yet.
The block I used is not a commercially available block, It is a custom job that my buddy machined out for us. It is actually a VERY nice block the way he did it. no drilling, no tapping, no pinning. It just screws on in place of the stock fill cap.
The current bottle on it is a non-regged bottle, so basically it is only there as a larger reservouir.
Eventually, once my QB comes in I may have him make me another to use the regged Ninja bottle set-up.

UCChris · « **Reply #19 on:** July 09, 2015, 07:18:29 PM »

Sounds awesome Ron. PM inbound.

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Did a little more tinkering this weekend

Author Topic: Did a little more tinkering this weekend (Read 6520 times))