HFT500 problems

This is actually really common on many different pcps. Most don't have fully sealed transfer ports (for there full route) the katran for instance pisses air out the valve body and around the barrel. Whilst it's sometimes annoying it's pretty much always happening.

It's not enough to effect the accuracy,the actual amount leaking is really very small. Think what 5cc of 100bar compressed air looks like on firing.

The only way to stop it would be to groove the barrel to fit orings either side the transfer port drilling and then seal the threads of the barrel securing grub screw above the port hole.

I would just swap the offending grub screw for one with a smidge of very low power thread lock to seal it.

Guarantee it'll still make no difference over the chrono or down range though 😉

Edit*** it'll then just leak from the next furthest point,probably the back of the barrel area. Seal that, then the front of the breech block
 
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I was thinking of getting a HFT 500 to replace the S400, not so sure now as I've never had a leak on the S400, always holds air and always ready to shoot.
 
I think the point is that no PCP is completely sealed, and a tiny amount of air escaping has no effect on accuracy or power, as they are set up with this as a known.
Given that the HFT500 has proved it's self in various different areas of airgun competition. I wouldn't lose any sleep over this. I have shot an HFT500 and the only thing I noticed was how well it shot.
 
wildtapholer said:
I was thinking of getting a HFT 500 to replace the S400, not so sure now as I've never had a leak on the S400, always holds air and always ready to shoot.
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Chances are your s400 has exactly the same quirks,but you've not noticed as yet 😉

I can only think of a few rifles offhand that have a fully sealed passage of air from the valve to the barrel and they are all olympic 10m match rifles originally
 
Actually I can think of one...
Not like I haven't had tons of them over the years 😆
BSA hornet,ultra,scorpions had a fully sealed port arrangement.
 
Thanx for all the input on this.
Kinda wish I had kept my AA S410F superlite carbine lol.
I'm sure I will just have to forget about this and get used to it doing it
I will keep on using it as normal and chrono'ing just to keep an eye on it but might end up sending it to the Rat works for some fettling anyway and see if there is anything he can do to improve it.
Thanx again everyone 👍
 
Tillygti6 said:
This is actually really common on many different pcps. Most don't have fully sealed transfer ports (for there full route) the katran for instance pisses air out the valve body and around the barrel. Whilst it's sometimes annoying it's pretty much always happening.

It's not enough to effect the accuracy,the actual amount leaking is really very small. Think what 5cc of 100bar compressed air looks like on firing.

The only way to stop it would be to groove the barrel to fit orings either side the transfer port drilling and then seal the threads of the barrel securing grub screw above the port hole.

I would just swap the offending grub screw for one with a smidge of very low power thread lock to seal it.

Guarantee it'll still make no difference over the chrono or down range though 😉

Edit*** it'll then just leak from the next furthest point,probably the back of the barrel area. Seal that, then the front of the breech block
Click to expand...
Ye I have a medium strength screw glue I use for my novritsch guns so I will use a smudge of that👍
 
Android 84 said:
Ye I have a medium strength screw glue I use for my novritsch guns so I will use a smudge of that👍
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Whilst it's obviously annoying now you've spotted it ,they have all done it to some extent for over 30 years so try not to get wound up about it.

The results on the target circuits and even the br cards they can shoot is rediculous really. Very few guns can truly better the hft500, not without spending mega money.
 
Android 84 said:
Ye I have a medium strength screw glue I use for my novritsch guns so I will use a smudge of that👍
Click to expand...
The air will then just vent out of the front of the action block. The air leakage is between that part of the transfer port below the barrel, in the action, and the section of the transfer port cut into the barrel. That air will be lost somewhere, if not through that particular screw hole.

My walther LG300 has a custom machined barrel. The standard barrel has an o ring on the barrel each side of the transfer port, to stop this leakage. My custom barrel doesn't have these rings and does leak a fraction. It's mega accurate.

Most of the leaking air passes down the barrel and pushes the pellet out the end, all that PCPs do is control air leaks.

It's worth remembering that all Steyrs use what is effectively an air leak to trigger their stabilisers.
 
Archer50 said:
Yep, did the job perfectly and although I no longer own the gun, it still is.
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8 years 🤗 Pretty impressive
Just wondering how I've never noticed any leakage around that area when doing balloon test on barrels for firing valve leaks, suppose it's just on actual firing blast which is plausible
But air blast in or near this area, I would normally put down to dodgy, damaged or sometimes missing transfer port seal 🤔 Not unknown on the HFT500. Rog
 
The trouble is once it's in your mind it's hard to get it out , if you want it for precision shooting you will always blame that leak for missing, it also takes the shine off buying a new toy, reject the gun get your money back and if you still want one go around different dealers and try before you buy , try and keep your warranty in tact
 
Just shoot it, it's normal. This is a 5 shot unsupported group at 26 yards in a 10 mph wind, aiming off varying amounts of deflection. It was my first attempt, zero checking last Thursday. The gun is my 2001 LG300 that delivers a small leak on every shot. I used it on Sunday at the BFTA GP5. 47 ex 50. Missed a 38 yard stander and made 2 long range windage errors. Gun is perfectly functional. 20240710_101531.webp20240705_193338.webp
 
Rog5 said:
...air blast in or near this area, I would normally put down to dodgy, damaged or sometimes missing transfer port seal
Click to expand...

In my case it was simply that the barrel was a loose fit into the block and however much I tightened the grub screws, it wouldn't form a seal. It took two full wraps of PTFE tape!

Maybe I had a Friday afternoon gun, but the general build quality of that HFT500 was pretty bad and went a fair way to putting me off Air Arms completely - except I've just unexpectedly acquired an EV2 Mk4, as you do...... :cool:
 
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I am really happy with the HFT500 I was just not expecting it to have that small blast of air when fired and a few of my club members were shocked by this as well as myself. Would just like to say that now I have used a small amount of screw glue it is completely gone so now waiting for it to escape from somewhere else 🤣 but for now sorted. Thanx everyone for your input much appreciated 👍
 
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