consistancy problem

[deanothehunter 34]

hi all i have just had my gunpower stealth changed from .22 to .20 calibre they changed buddy bottle valve to suit new calibre which is new 2010 version of anti- tamper regulated valve so even if top hat came loose and unscrewed the power cannot go over 12 ft lb and this is true as i tested it, it shoots fine but is very inconsistant in fps for example jumps from say for instance 523 fps to 600 fps then back down to 5 something therefore trying to zero is almost impossible as when pellet after pellet hits the mark you think yes spot on then all of a sudden velocity goes up and down again making pellets strike much higher or lower than zero, i mean every gun is slightly up and down velocity wise but usually so small ammount either way it does not cause you to be off zero from shot to shot any ideas anyone please help its very frustrating ...............<IMG id=smid_8 src="http://www.thehuntinglife.com/forums/public/style_emoticons/default/wallbash.gif">

[andyfr1968 772]

I'm no expert on PCP's but if it was shooting well before, I'd put money on the valve being at fault.

 

The caliber change won't account for that 'cos there's no poor quality pellets for .20. The bottle shouldn't matter, so it only leaves the valve.

 

Maybe it needs some time to bed in and settle down, an hour or so's informal plinking may help...

 

Hope it works out for you, mate.

 

Cheers.

[deanothehunter 34]

cheers extreme hunter its the 2nd valve in 2 months 1st one leaked and was faulty this one seems ok it shoots fine but i know all guns vary consistancy wise according to pellet etc but usually no more than a ten ft per sec from shot to shot mines very eratic jumping up and down massive ammounts .......cheers anyway if it dont settle its going back once again

[Phantom 631]

hi all i have just had my gunpower stealth changed from .22 to .20 calibre they changed buddy bottle valve to suit new calibre which is new 2010 version of anti- tamper regulated valve so even if top hat came loose and unscrewed the power cannot go over 12 ft lb and this is true as i tested it, it shoots fine but is very inconsistant in fps for example jumps from say for instance 523 fps to 600 fps then back down to 5 something therefore trying to zero is almost impossible as when pellet after pellet hits the mark you think yes spot on then all of a sudden velocity goes up and down again making pellets strike much higher or lower than zero, i mean every gun is slightly up and down velocity wise but usually so small ammount either way it does not cause you to be off zero from shot to shot any ideas anyone please help its very frustrating ...............<IMG id=smid_8 src="http://www.thehuntinglife.com/forums/public/style_emoticons/default/wallbash.gif">

 

I have an Idea

 

Take it back and tell them that the regulated valve aint regulating properly

A regulated valve means it regulates the amount of air that passes it; so it should allow the same amount of air for each and every shot (or very close to the same amount) if your readings are that inconsistant, then I'd say the regulator is fecked

 

Phantom

[deanothehunter 34]

cheers phantom i think thats what gonna happen its been back 6 times in as many months for different problems i think they should give me new one for all i spent on it and the back and fourth petrol etc then get it home to find it still is playing up .....lol...........

[matt_hooks 188]

Mate, if you bought it from a dealer, then you probably have a right to demand a replacement or refund. Sale of goods act says it has to be fit for purpose, of a reasonable quality and substantially as described. If it's not working properly then you'd be within your rights to ask for a refund or replacement.

 

The fact that you've allowed them a few attempts to sort the rifle out and they've failed, you should push them for a replacement. Don't let them fob you off with "it's been altered now so we can't take it back" unless you did the alterations, or someone who doesn't work for them did. You have a right to expect the rifle to work like a rifle, i.e. to put shots in the right place reasonably consistently (assuming you do your part).

 

Good luck getting it sorted!

[Alexisrouzee 6]

hey bud, i have a modded storm and the problem with the firing sequence of any gunpower is that it is half hammer half precharged, i have spent hundreds to try and perfect the flaw but you will never be away from it totally i found.... starting with a big problem is it was designed for the states where they have no limit on power (airforce condor/talon) so nothing restricts the air release but to sell it in the UK they fit a valve insert to the rear of the valve assembly (that also keeps the kinda weak valve spring in place) which shouldn't be a problem really but then you have the firing sequence, a under powered main spring as standard which forces the hammer onto the breech which then in turn pushes down the top hat that pushes in the valve stem against the weakish valve spring............ now all you need is a slight catch on the hammer, the spring to lose a little power, the valve stem not to penetrate into the bottle the same amount and you will get bad inconsistencies, but as already stated it may settle down over a few pellets going down the barrel and try some different pellets, i found accupell or crossman premier do the trick and have a tight seal. have you been dealing with geoff at gunpower??

[deanothehunter 34]

yeah been dealing with geoff i have to say he is ok very helpful its just when it goes off to his engineer they had it a few days several times then said its ready so i collected but getting bored with drive each time its approx 40 miles each way which isnt that far but would be far more happy to do so if when i got it back it was working ok well this was 6th time they had it well over a month this time but its shooting fine just inconsistant although the top hat had,nt been thread locked i noticed and had wound in slightly after each shot therfore the valve stem could,nt go in the correct distance to regulate each shot so now i sorted that out which locktite i moved top hat out to end of valve stem so stem is now flush with top of top hat so now when hammer strikes its going in all the way it needs unhindered so is shooting much better and on chrono each pellet is,nt always the same fps but very close now plus when i weighed each pellet that was supposed to be 12.8 grains in .20 some were 13 some were 12.4 and 12.6 so thats obviously why the differences but now are within an acceptable limit so fingers crossed plus i have not had it back long enough to test many pellets through it not that theres many to choose from in .20 cal but been told jsb exacts in .20 are unbeatable and very high quality so goona try them. the ones i tried were bisley pest control and superfield but were surprised by the weight differences between each pellet still i,ll see how she goes now had it 8 years without a problem before it started playing up so lets hope i now get another 8 lol ..........cheers.............

[andyfr1968 772]

Glad it's sorted, mate.

 

I've been useing .20 for the past couple of years now and I'm well pleased with it!!

 

Check out H and N Baracuda's and Dynamic SPC5's too. Best I've found for my HW90. The JSB's work very well but those two have the edge in mine...

 

Cheers.

[deanothehunter 34]

cheers andy i,ll bare those in mind hopefully i will have good day 2 moro cant wait pre-charged are great and been using my stoeger x20 springer its good accurate and has accounted for loads of quarry but once u take the pre charged route its hard to go back to springers lol

[andyfr1968 772]

I'm doing it the other way round. Started with springers 30 years ago and got my first PCP about a year ago, an AA410c. Lovely gun, I really can't fault it.

 

However in recent months, buisiness has gone to sh1t and I need some quick cash. The 410's up for sale but I won't part with my 90..... I'm by no way saying a springer is better than a PCP (or the other way round...), it's just me, I'm a funny bugger.

 

Glad it's all sorted, mate.

 

Cheers.

[Phantom 631]

cheers andy i,ll bare those in mind hopefully i will have good day 2 moro cant wait pre-charged are great and been using my stoeger x20 springer its good accurate and has accounted for loads of quarry but once u take the pre charged route its hard to go back to springers lol

 

Nah, PCP's are the best for hunting; due to the removal of recoil. thus increase in accuracy

 

I'd shoot my springer all day long if I had the land to do it on. Much more a sense of achievement when the quarry goes down with a springer

 

Phantom

[andyfr1968 772]

I dunno, Tony. I can shoot the same groups with the 90 as I can with the 410.

 

That said, the 90's a very easy springer to use, low recoil, VERY quick lock time and the best trigger I've ever used, airgun, rimmy, CF, anything...

 

The only thing I'll really miss when the 410 goes is the ability to have a fast second or third shot but if I've done my bit to start with, that's not an issue.

 

The other nice thing about my good old 90 is I'm farily sure it'll out last me and with no faffing about with all the extra gear that's needed with a pre-charge.

 

I will get another when funds allow (.177.. 'cos they don't do them in .20), 'cos it's a class act that I've enjoyed while I've owned it.

 

Needs must an all that....

 

Cheers.