thinking about getting a .177 barrel for my DBO ...... it has a AC Customs flat top piston and valve , the valve has had the exhaust port angled , the stem has been turned to improve flow and it's been faced/flat topped and i'm using the stock transfer port . i was wondering what folks using a similar set up with the 18 or 24 inch barrel are getting with 5 , 10 and 15 pumps ? please tell what pellet/weight you used too .
i want to try .177 because of the wider variety of inexpensive pellets in .177 . i'll be doing %99.999 plinking and paper target shooting .... although i'm sure a .177 at 700 fpe will handle squirrels , rabbits and birds at the modest range i'd feel comfortable shooting them . i know the guns and their mods will vary a bit in actual performance so i'm wanting to get a ball park figure for playing with chairgun .
thanks :)
I have roughly the same setup with a .177, 24" shrouded barrel, Mellon ft/fv, ported & profiled valve internals, stock TP, extended probe.
I'm getting 9-10 fpe with JSB exacts and exact heavies @ 10 pumps.
Favorite are the exacts, shooting 705fps at the muzzle.
At 4 pumps, exacts shoot 500fps for 10m target speeds.
Hope that helps.
JMJ
(http://i1218.photobucket.com/albums/dd418/JMJinNC/Crosman%20PC77%20Carbine/AA36F38E-0CE0-43FC-85F4-5F88CFF6AF83-6922-00000B6120BEB440_zps74f85259.jpg) (http://s1218.photobucket.com/user/JMJinNC/media/Crosman%20PC77%20Carbine/AA36F38E-0CE0-43FC-85F4-5F88CFF6AF83-6922-00000B6120BEB440_zps74f85259.jpg.html)
thats very helpful :-* 500 fps @ 4 pumps is very nice . going by this thread ...
http://www.network54.com/Forum/275684/thread/1318040664/1377+to+1322+upgrade,+my+results.++Need+stronger+hammer+spring- (http://www.network54.com/Forum/275684/thread/1318040664/1377+to+1322+upgrade,+my+results.++Need+stronger+hammer+spring-)
thats about what my stock DBO did with just a 24 inch .22 barrel added does with 10 pumps . :)
9-10 fpe with just 10 pumps means there's a few more FPE available if i want/need them on occasion .
ya just gotta love the versatility pumping allows :-* and with zero recoil ;) :-*
Pardon me, what is a TP? I have seen it mentioned often.
Transfer port.
Here is mine. It has the FTP&V ported a little in the valve, stock port, ext probe, and 17'' barrel. It gets 9-12 FPE with up to 20 pumps. (usually only pump to 15-17 if I feel full power is needed)
Here is 13g pellets @ 17 pumps:
(http://img.photobucket.com/albums/v465/CWLONGSHOT/Temp%20stuff/sporting%20pics/Air%20guns/Crosman%201377/null_zpsa82f4f01.jpg)
Here is 9.3g @ 17pumps:
(http://img.photobucket.com/albums/v465/CWLONGSHOT/Temp%20stuff/sporting%20pics/Air%20guns/Crosman%201377/null_zpsa4e2cf3b.jpg)
Here is 11g at 12 pumps:
(http://img.photobucket.com/albums/v465/CWLONGSHOT/Temp%20stuff/sporting%20pics/Air%20guns/Crosman%201377/null_zpsed5e84f2.jpg)
Here is 7.2g @ 14 pumps:
(http://img.photobucket.com/albums/v465/CWLONGSHOT/Temp%20stuff/sporting%20pics/Air%20guns/Crosman%201377/null_zpse8067e32.jpg)
Here is 7.2g @ 20 pumps:
(http://img.photobucket.com/albums/v465/CWLONGSHOT/Temp%20stuff/sporting%20pics/Air%20guns/Crosman%201377/null_zps8281d9d8.jpg)
Here is 13.6g @ 17 pumps:
(http://img.photobucket.com/albums/v465/CWLONGSHOT/Temp%20stuff/sporting%20pics/Air%20guns/Crosman%201377/null_zps629bfc80.jpg)
Here is 11g @ 4 pumps:
(http://img.photobucket.com/albums/v465/CWLONGSHOT/Temp%20stuff/sporting%20pics/Air%20guns/Crosman%201377/null_zpsb1e89ce2.jpg)
JMJ,
I would love to add that cheek piece to mine! LOOK GREAT!! How did you make it or was it bought? HELP PLEASE! ;)
CW
Thanks. I made the cheek rest. A search on this forum for "JMJ" and "cheek rest" should turn up the details.
JMJ
Mr. JMJINNC is a genius he gave me autocad drawings for the 1377 barrel band/pivot plug so I had one made in ss via cnc machine..Here is the proof :-* Ain't she cute ;)
(http://i709.photobucket.com/albums/ww96/DARKHORSE1967/IMG_0843_zps30de1368.jpg) (http://s709.photobucket.com/user/DARKHORSE1967/media/IMG_0843_zps30de1368.jpg.html)
(http://i709.photobucket.com/albums/ww96/DARKHORSE1967/IMG_0841_zps5a730748.jpg) (http://s709.photobucket.com/user/DARKHORSE1967/media/IMG_0841_zps5a730748.jpg.html)
Cwlongshot - awesome report! Good on you!! :-* :-* :-*
I have a 1377 built by Roy at Mountain Air (with all the goodies inside and out) and if I remember correctly, with a 19" barrel I am/was getting 700ish fps with 7.9 pellets with 12 pumps. Accurate as hell, too.
I have a choice 24" Mellon barrel I am going to put on either the above-mentioned 1377 or perhaps another Mountain Air 1750 waiting to get some attention. More to come.
Have a great one and take care,
Noah
What would be the optimal barrel length for a pumper? As a pistol, I would like it not more than 12" or it would become awkward to handle. A 17-18" barrel would be ok for a carbine with a shoulder stock. Is there more efficiency to be had between 12" and 17"? Thanks,
Quote from: Hung2 on December 01, 2013, 10:23:25 PM
What would be the optimal barrel length for a pumper? As a pistol, I would like it not more than 12" or it would become awkward to handle. A 17-18" barrel would be ok for a carbine with a shoulder stock. Is there more efficiency to be had between 12" and 17"? Thanks,
True that on a pistol having a longer than 12" barrel does become sort of awkward, but I just sit around the range resting the gun(s) on sand bags while paper punching, so, mobility is not a huge concern for me.
I am most likely wrong, but I sort of remember the rule of each inch of a barrel should produce around 10 additional fps. ???
Darn, I just chopped my 2289 barrel down to 11.5". This is the most appealing length to me as a pistol. My be I should have left it at say 12.5".
thanks for the additional replies folks :)
some mighty fine lookin guns too :-*
nice rigs!