Accuracy problems, some HELP please gents

[redeye jedi 39]

Hi gents, I got my hw100 back from Hull cart on friday. It was in for re-sleaving & threading of the valve housing and air cylinder. I sent the said items plus barrel and silencer. Ive got a slight leak on the air cylinder (going back to HC to be fixed) but on sunday when i tried to zero the shots were all over the place. Zero range was 30 yards inside a green house so wind was not an issue. I was using a spare cylinder that wasnt leaking. I could get 2 shots almost pellet on pellet but then the next few would be either a mill dot left or right or low Ive checked the silencer and there's no witness marks what so ever that i can find. Rifle does seem to have some punch to it, and im not getting many shots from a 200 bar fill. think i got 35 shots to just under the 90 bar. ive not got a chrono to test it im just wondering if its kicking out more ftlb would this affect accuracy like this? as ive heard some fac hw100 are terrible accuracy wise. i was using RWS superdomes as these normally group really well with this rifle.

I Dont even want to take this thing out the case, if its over power the last thing i need is a firearms offence hangging over me. if anyones in the wiltshire area with a chrono that could help that would be fantastic.

Any advice would be a great help thanks guys.

 

ATB

 

Dom

[Sweeney-Todd 208]

Hi Dom.

 

I had a simular problem with mine a while back.

New rifle, and the power crept up to about 12.40, accuracy went to pot.

Also barrel came loose, which added to the problem.

 

I have recently sent mine away to Adi at A&M Custom Gunsmiths.

 

He has set the reg and hammer tention, decreased lock time.

Set the rifle ftlb to what I wanted.

Lapped the crown.

Also some other work to the interals that I asked for.

Added another grub screw to secure the barrel.

Trigger sears polished too.

 

The consistancy of the rifle is now spot on, all for the princly sum of £130 inc return post.

 

Cant reccomend the guy enough mate, might be worth thinking about.

 

A&M Adi.......01623861308

 

 

Just a thought buddy .

 

ATB.

 

 

 

Bill.

[redeye jedi 39]

Hi Dom.

 

I had a simular problem with mine a while back.

New rifle, and the power crept up to about 12.40, accuracy went to pot.

Also barrel came loose, which added to the problem.

 

I have recently sent mine away to Adi at A&M Custom Gunsmiths.

 

He has set the reg and hammer tention, decreased lock time.

Set the rifle ftlb to what I wanted.

Lapped the crown.

Also some other work to the interals that I asked for.

Added another grub screw to secure the barrel.

Trigger sears polished too.

 

The consistancy of the rifle is now spot on, all for the princly sum of £130 inc return post.

 

Cant reccomend the guy enough mate, might be worth thinking about.

 

A&M Adi.......01623861308

 

 

Just a thought buddy .

 

ATB.

 

 

 

Bill.

 

Thanks bill, that was going to be my next question if I couldn't get to the source of the problem with advice given on here.

 

ATB

 

Dom

[pianoman 3,587]

Hi Dom.

I don't shoot pre charged rifles but, this sounds clearly like you have an unstable power/muzzle energy issue if your ammo is grouping fine then, going wild and you are running out of air in the cylinder much quicker than normal.

 

I do know that the higher the muzzle energy from Pcp rifles, the more air they draw from the cylinder and thus the fewer shots per fill. A chrono test will only serve to record the levels of deviation taking place. You could try phoning a good airgun dealer in your area and explain what's been happening and arrange for him to make a thorough test of the rifle and come up with a diagnosis. At least that will save you from having the gun siezed and turned over to the police, while having it legitimately checked out.

 

If this is the result of work carried out by Hull Cartridge, it lies with them to put this right. It's not just the legal matter of the law, it's the fact that you have a great rifle and it's next to useless for hunting or anything else right now.

 

ATB

 

Simon

[redeye jedi 39]

Hi Dom.

I don't shoot pre charged rifles but, this sounds clearly like you have an unstable power/muzzle energy issue if your ammo is grouping fine then, going wild and you are running out of air in the cylinder much quicker than normal.

 

I do know that the higher the muzzle energy from Pcp rifles, the more air they draw from the cylinder and thus the fewer shots per fill. A chrono test will only serve to record the levels of deviation taking place. You could try phoning a good airgun dealer in your area and explain what's been happening and arrange for him to make a thorough test of the rifle and come up with a diagnosis. At least that will save you from having the gun siezed and turned over to the police, while having it legitimately checked out.

 

If this is the result of work carried out by Hull Cartridge, it lies with them to put this right. It's not just the legal matter of the law, it's the fact that you have a great rifle and it's next to useless for hunting or anything else right now.

 

ATB

 

Simon

Thanks for the reply Simon, the only reason i thought it might be over power was because of the low shot count. I thought a chrono could tell me fps and the ftlb im running at? My nearest airgun dealer is over an hour away and i dont get any time during the day to get there during normal opening hours i was hoping it'd be something simple or a common fault that i could try before either buying a chrono this weekend or sending off to A&M for investigation.

 

ATB

 

Dom

[Buster321c 1,010]

Muzzle flip ?

[redeye jedi 39]

Muzzle flip ?

 

You've lost me there buster me old mate.

 

ATB

 

Dom

[Buster321c 1,010]

That might be the wrong description .

[redeye jedi 39]

That might be the wrong description .

 

 

[Buster321c 1,010]

I mean the pellet flying erratically when it leaves the muzzle , because the end of the barrel is not 90* square to the bore .This is to ensure the projectile leaves the barrel at the same time around it's circumference and flys straight , if it was to leave on one side of the skirt before the other , it will cause the pellet to become unstable and fly erratically .

[pianoman 3,587]

Anybody had similar issues with anti tamper devices? Could one of these things cause this?

[redeye jedi 39]

I mean the pellet flying erratically when it leaves the muzzle , because the end of the barrel is not 90* square to the bore .This is to ensure the projectile leaves the barrel at the same time around it's circumference and flys straight , if it was to leave on one side of the skirt before the other , it will cause the pellet to become unstable and fly erratically .

 

Thanks buster make sence to me now. i'll give it a look, maybe change the barrel o-ring and see what happens.

 

cheers

 

Dom

[Buster321c 1,010]

Thats a crap description , but i know what i mean ....... might need re-crowning

Edited February 21, 2011 by Buster321c

[Millet 4,497]

Personally i would try fastening the gun somewhere solid so it wont move, lets say in something like a black@decker work mate or vice, that way you can rule a scope problem out as the barrel will be pointing in the exact same position each time you fire a shot,i would also remove the silencer to rule that problem out as well,but going from what you have said about getting less shots from a fill i would favour that the gun is firing too much air out with each shot and a crono would be the way forward.

[andyfr1968 772]

Anybody had similar issues with anti tamper devices? Could one of these things cause this?

 

Anti tamper device...

 

Is that like a chastity belt for airguns??