FAO those running regulators.
I received my 24″ the other day and I’ve only managed a quick plinking session (and a very quick hunting trip 😉 ) and accuracy seems much improved. However consistency Isn’t.
With my 12″ barrel I was getting around 3 FPS variation which I thought was pritty sweet. Now I’m getting around 11-13 FPS variation. I have tried with hardy any preload on the main spring and adjusted the valve spring retainer for best power and I got 13 FPS variation. I then took out the small spacer and added my biggest one and I got 11 FPS variation with an increase In power of around 1-3 FPS. Obviously I had to put more preload on the valve mainspring as It was tank dumping. I don’t know how much this variation will affect accuracy down range but If I can keep everything as tight as possible that has to help.
After that I’m thinking the least mainspring tension the better right as It’s less recoil and should make the gun smoother and less pressure on the trigger? I would still like more power – Even If It’s a few more FPE – But the only way I can see this happening Is a larger regulated air resevoir or a bigger bored valve stem (or of course an aftermarket valve, Blod or Lang). I think my bore Is 3.5mm now but would an extra .1 of a mm give me the extra FPE? I don’t want to go too big incase the stem collapses but combined with the light spring preload I should get away with It…?
What about enlarging just the top hat bore so the air can escape from the stem quicker? I’m using a 1 piece custom stem and tophat so there’s plenty of metal surrounding the TH.
Your thoughts?
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Ooooooooo I like that Idea. To bad I have a tank now.
If you sell the pump, you only need to fork out about a ton. AND IT IS ANOTHER TOY!!!!
But fair play to you mate if you dont mind doing it.
I’m looking for a spare pump actually. My current axor pump i have had for years and had no problems at all with It. I paid 60 quid and that was perhaps 5 or even more years ago now. Pritty good value I think. I havn’t even ahd to replace a seal.
I suppose I could try and get a custom microbore fill line made up that can connect the 2 pumps so one can cool while I pump the other 🙂 Saves switching them and building the hose pressure back up all the time 😉
Buy a second pump. Then you can pump continuously by switching pumps. 😆 😆 😆 😆 😆 😆 😆
You’re probably right Pabs but that 200 I could spend on more toys 😆 I always seem short on cash (don’t we all 😆 ) so 200 Is too much for me. Then I have the hastle of filling, test etc. I don’t mind the pumping to be fair. Filling by bottle will be much easier yeah, but I need the exercise before I develop too much of a gut 😆 It’s the waiting for the pump to cool down that does my tests In!
Fusion, get a scuba bottle mate. I just got one and I giggle to myself everytime I top up 😆
Shooting just got a whole lot more fun again! It means you can test till the cows come home and not have that gutting feeling knowing that you gotta pump the bottle again. And as for tank dumps 😯 Sod right off pumping that badboy back up by hand again….
And how long do you have to wait after pumping till your in a fit state again to shoot well?
Best £200(12ltr 300bar) I’ve spent in a long while, and I really do mean that. If you are a serious shooter(and I figure you are) do yourself a big favour and get a bottle. I guarantee you will not regret it.
I think I’ll have to call at the local gun shop and buy some 5.50’s. I’m using 5.52’s now and they are a very tight fit. I think I’m damaging them In some way getting them In as the groups I’ve just shot at 35 yards are pritty crap! I was almost getting 2 seperate groups. 1 smack on the bull and another about an inch off bull 😕
I thought I’d try some accupells but I couldn’t even get the head of the pellet In In the barrel!
Yeah – less recoil has to be good. I’ve took a spring out of the trigger too and I’ts much lighter now.
With the regulator I think alot Is governed by the valve and the preload on the valve spring as It doesn’t have the internal bottle pressure closing the valve up after every shot.
I don’t mind the pumping, It keeps In shape the amount of tank dumps I’ve had 😆 It’s the waiting around for the pump to cool down that pisses me off!
what numbers are you getting now?
after reading about your findings i am thinking of putting in a slightly lighter spring that i have, Drums std replacement, instead of BN’s stronger one.
having less recoil has to be better if the FPS is about the same.
Like you i am happy to use just a hand pump but i am getting quite a few shots out right now on evening hunts and the bottle is going to be so much easier. not to mention there is a filling shop anout 10 miles away.
Strange. Could be anything but all I know Is Biz Mags are real tight!
Mine was new from Drum also and was alway a comfortable fit so thats odd. I uess a different batch and yours was milled thinner!
Thanks B. I’ve got some other ideas first before I go messing with the reg but thanks for the offer and I may take you up on It after I have tried the other (easyer) ideas.
I found the biz mags are really hard to fit In. Perhaps It’s just because my barrel Is brand spanking and needs to be worn In abit. I’ve probably only fired around 100 shots or so. Even my usual 5.52 AA Fields are a very snug fit. Still as long as the pellets can handle It and I’m getting good groups I can’t complain 😀
I need new batts In my combro too. I don’t know how much the low power effects the combro but I’ll try some more strings and see what I get.
I think the reg is happy with it as i just put 100psi or 0.2 mm spacer in mine and it works a treat. getting about 13fps variation now though but i thinks that is more that i have put new batteries into my chronie and done more then 20 shots with it.
i have some shims i can send if you want to try it out. i was sent them from matt at expert hpa.
my barrel is a BSA job and they test the barrels with bisley pellets and i have found the mags to be a comfortable fit.
Will the reg mind being played with B? I know some don’t and then go all over the place and that’s the last thing I want. I think an extra .2-.4 of a mm will do me but I’ve got some other options to try first save draining the whole tank and then refilling by a hand pump 😆 Where do you get the shims from too?
I was looking to get a bottle but once I’ve set the gun up It won’t get used. I only need one for quick fill ups while I’m testing so I’m plodding on with my pump.
Do you use biz mags In your BSA barrel? I’ve tried them and can hardly get them In my barrel. I was gonna try those rabbit magnums but don’t think I have a chance of getting them anywhere near In!
its a different direction but might do the job.
on your reg you will have 2 burst disks one will be arround 5K and the other being 1.8K or 3K.
If its 1.8k get it changed to a 3k.
now add a some shims 🙄
0.1mm will give about 50psi
0.2mm will give about 100psi
stick in 0.2mm and i recon you will be somewhere arround the 790 – 800fps mark if you running the setup i remember you having.
hope that helps…..
i am hoping to get a divers bottle soon and when i do i will be doing a few more tests to see what i can get.
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I have a tank here actually. I bought It years ago and never used It. I bought a 207 bar one 😳 Good job It was only cheap 😆
I may give It ago LMTSS when I get a spare pump. I don’t know how long that will be. I like a bargain…. In other words I’m just a tight bastard 😆