GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Mole2017 on June 03, 2017, 10:13:32 PM
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Just thought I'd share my experience with a generic hand pump on a PCP. I bought my R10 used and after 6 months (!) I finally had it all cleaned, reassembled and ready to gas up...no leaks this time :)
I purchased a hand pump on eBay for about $70 or $75 (http://www.ebay.com/itm/252722509740?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/252722509740?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)). It's ok quality-wise. The feet don't flip down quite flat. One seal on the hose was pinched or wrung as it was screwed together and blew out when I first tested the pump. I replaced it with a spare (and greased it so it wouldn't do it again). It slobbers oil at the base of the pump, but I haven't torn it down to clean it up and use grease instead. It grates just a hair at the top of the stroke--I'll find out what that is when I open it up to clean and grease.
I had bought a fill probe for the BSA, but it was a screw in type with threads that don't match the end of the hose. Instead of finding an adapter either for the threads or the foster disconnect, I put mine on a lathe and turned it from screw threads to foster connector. I think I could have bought a foster version from the start, but I didn't realize that then.
Anyway, in use from start to finish, it was about 20 strokes needed for about every 225 psi gained (See figure below). That would work out to 290 strokes to fill my 200 cc bottle from dead empty, but I stopped at 280 just because it was close enough.
Now, if I'm feeling optimistic, I weigh 130 pounds. Effort was negligible until about 1400 psi. By about 1800 psi I was having to lean into the pump some. By 2500 psi, I would have to add a little shove to that lean--just to cram the last couple inches of the stroke. The pump is kind of short, so it isn't very stable to try to keep both feet on the stirrups. One will do, though I was turning my leg a little bit to get my knee behind the pump for stability (That's worth a picture...I add that tonight or tomorrow when I pump the rifle up again). By about 2700 psi and beyond, I was having to throw my weight on this pump--foot off the stirrup (with my other out behind me a bit for stability) and add a shove with the arms to get the last of it at the highest pressure. If you are lightweight like me, don't do this on surfaces that might let the pump slip. I had a piece of carpet under the pump, but I think I'll make a platform I can stand on and fasten the pump to it so I don't need a foot on the stirrup.
I did stop for breaks, mostly to let the pump cool, which was maybe the first at 120 strokes (that could have been for me), then 180, 220, 240, and I think every 20 after that (for some reason I didn't note it). I was doing things in increments of 20 so I could record the data for the chart below. It's a fair workout; you'll break a sweat if the air is warm.
As for how long that lasts in the R10, stay tuned for a separate thread about that.
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If you thought that was bad dont ever pump up an Airforce pcp from empty. They are almost 500 cc bottles and I know how much time it takes cause I did it a time or two ;D In fact thats what drove me to buying my tanks. The exercise was good and if you used good technique its not that bad but I dont like so much down time when I want to be shooting. I didnt catch what caliber your r10 is or the fps if you know that yet but if it is a .22 and set for about 28 fpe with the proper hammer pre load for the reg setting you should get about 35- 40 shots. At least thats what my memory tells me about my .22 R10 ;) I did tune mine down just a little more to 26 fpe with 18 gr JSB just to extend the shot string a little. Let us know how it goes for the tune and accuracy.
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Here's a picture of how I hold my knee behind the pump. It's not really pressed hard there, but it is useful for when I start having to completely lift my right foot to put more push into the stroke. I rolled the cuff of my pant leg to keep it out of the slobber at the base of the pump tubes.
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If you thought that was bad dont ever pump up an Airforce pcp from empty. They are almost 500 cc bottles and I know how much time it takes cause I did it a time or two ;D In fact thats what drove me to buying my tanks. The exercise was good and if you used good technique its not that bad but I dont like so much down time when I want to be shooting. I didnt catch what caliber your r10 is or the fps if you know that yet but if it is a .22 and set for about 28 fpe with the proper hammer pre load for the reg setting you should get about 35- 40 shots. At least thats what my memory tells me about my .22 R10 ;) I did tune mine down just a little more to 26 fpe with 18 gr JSB just to extend the shot string a little. Let us know how it goes for the tune and accuracy.
Yeah, I'm new to this PCP thing and I've already made a discovery: you will shoot pellets like there is no tomorrow. It's so easy...until you run out of air.
Speaking of which, I'll leak some of my information I was going to post separately about this R10. It's a 0.177. I bought it used with zero information about its history. I had to take it apart to free a stuck regulator and clear gummy trash in the fill port check valve. Putting it together I had no reference points where to set the regulator and such, so I took an educated guess. I figured I might as well try sighting it in, and then proceeded to shoot until empty, tracking the tank pressure with each magazine or two.
Eleven, yes eleven!, magazines later the pressure is down to 55 bar and I've concluded that maybe the POI has finally started to drop off in the last five shots (barely 2" at 25 yards though...). "Nearly 100 useful shots...what have I got here?" I wonder to myself. Did get a non-FAC unit or something? Maybe BSA can tell me from the serial number.
Most likely it is just that the regulator is set really low. Not having a chrony at the moment I'm going to guess the pellets have got to be 800 FPS or less, but not by much: the trajectory arc out to 25 yards is a lot like my CFX which is just over 800 FPS, but has the scope closer to the barrel centerline. When I started shooting this morning, the sun was behind me and I learned another thing: PCPs let you watch your pellet go downrange if the conditions are right (and maybe if your pellets are slow too). We'll start in on the tuning eventually, but I could get used to this kind of shot count :)
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Pumping is the price you pay if you only have a handpump. My Benjamin pump has done me well thus far.
I've refilled my QB79 bottle 6 times from 850 psi in one day back up to 3000. It's only 13 cubic inches.. 213 cc... 6 times..
But I've also filled my PP700 pistol 14 times on two separate occasions when shooting a bunch. Only 67 cc, but yeah, 14 times is a lot.
Bottom line is pumping is good exercise, yeah buddy!