PCP Questi&#111;ns

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Topic: PCP Questions
Posted: 02 Feb 2026 at 7:50pm

Hey all,
I'm thinking of getting a PCP pistol, can anyone please give me a PCP for dummies explanation of why the need to adjust the hammer travel length,
Also what do most people use to charge up their guns

KrisNZ

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Posted: 02 Feb 2026 at 8:54pm

Here's a animation of how a pcp rifle works. The auto dubbing is very robotic but the animation should give you a good idea of how the hammer works.
https://youtu.be/n8qrTADvK1A?si=dbWsTk4fsR-ymvvI
Im not a pcp shooter but from my understanding the harder the hammer hits the more time the valve is open to let the compressed air through to the barrel.. You can adjust the length/power of the hammer strike to adjust how much air gets through by how long the valve is open.
By being able to do this you can adjust the amount of power/air is pushing the pellet, allowing you to tune for best accuracy, speed/power of pellet.
Adjust it if you use a heavier or lighter pellet etc.
Someone more onto it can give you a better explanation but i believe thats the basic jist of it.

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Posted: 02 Feb 2026 at 10:04pm

Hi Kris,

It is usually only the top end PCP’s that have adjustable hammer spring tension, or that you can tinker with the hammer weighs or transfer ports etc.
Most of the older PCP’s were not adjustable, the hammer weights and hammer spring tension etc were set from the factory, and usually shot very well just as they were, no adjusting necessary.

It’s only in recent years that manufacturers started adding all the adjustable “tuneable” features to guns, but honestly, the majority of air guns from decent manufacturers dont need to be fiddled with.

As far as refilling the gun, there are 3 options, and pros and cons to each.

1- manually pumping it up to 200, 230, 250 or 300 bar (depending on the make and model of gun)
I dont think there are any pros to manually pumping 🙈 other then its cheap. I wouldnt recommend it unless you were young, fit and stupid.
2- scuba tank. Get it filled from a dive shop, $5 or $10 for a top up, will last you months.
Pros- second hand dive tanks are not expensive. Portable. Cons- no good if you don’t have a local dive shop. Most scuba tanks are rated to 230bar, 300bar tanks are a bit more expensive. Most dive shops will only fill a tank to 220bar. Very few dive shops will pump to 300 bar. Having said that, very few guns can take 300bar, only newest/expensive models.
3- by your own compressor. Pros - some can pump up to 300bar. Cons- expensive and need maintence and services/filters etc. I think only the best/most expensive ones can dry the air so you don’t get moisture into your guns cylinder 🤔. Can only fill the gun if u have electricity.

Other guys will tell you their pros and cons to each system 👍🏻

Walk quietly, but carry a big stick.

Kris

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Posted: 23 hours 30 minutes ago at 8:30am

Thanks, so the closer the hammer to the valve, the longer the opening duration is? Make sense,
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Kris

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Posted: 23 hours 28 minutes ago at 8:32am

Thanks for that, yeah a mate said the hand pump was a waste of time, I'm old, so a scuba tank sound like the best option. Plenty of dive shops in Nelson,
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Posted: 22 hours 43 minutes ago at 9:17am

I think its the other way around. The further back from the valve the hammer is, the more compressed the spring that drives the hammer forward is. That gives more compression on the spring hence more power. It also allows the a tad more travel to build up speed.
That means it hits the valve stem harder ( or just say the valve if your not sure where the valve stem fits in the picture)
The harder the valve is hit, the further back into the pressurized air it is pushed. That means the valve is open longer and more air can eacape into the barrel.
Note we are talking about tiny amounts of time this happens in. A few thousandths of a seconds open longer makes a difference to high pressure air escaping into the barrel.

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Posted: 17 hours 24 minutes ago at 2:36pm

I went through this a while ago, and decided that buying my own compressor was best.

I only fill direct to gun, but have a pump that will do a cylinder.

Firstly, a dive shop will only fill a certified tank, and that needs to certified every 12 months (?), then a more expensive test every 5 years (?).

In Richmond they quoted me $30 to fill or top up a tank.

So...first I bought a GX CS4 compressor. Water cooled, 5+ hours run time, can run off 220 volts and 12 volts (portable).

But about a year later I decided to get something 'better' (maybe) and sold the CS4 to buy a Hills Evo-310 pump (ex UK).

The CS4 will pump up to 4500psi easily. The Hill's only 3000psi..but I only need 2000psi anyway.

Your options are a GX CS2, CS3, or CS4 really, and for the money I think the CS4 is better (CS2 and CS3 are air cooled but both also are 220v and 12v).

https://gxpumpofficial.com/

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Posted: 16 hours 47 minutes ago at 3:13pm

Whats the difference in size between a pcp pistol air cylinder and pcp rifle air cyclinder?

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Posted: 16 hours 33 minutes ago at 3:27pm

My rifle only has a 220cc cylinder (but it is single shot target rifle).

Huma Air has a PCP pistol with 480cc cylinder.

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Posted: 15 hours 30 minutes ago at 4:30pm

For what you're doing this may be a good option. We have a water-cooled version at our gun club which has been very reliable and gets quite a bit of use. Limitations are that it runs on 220V and is not big enough to fill a storage cylinder that you may want to take with you.

https://www.aliexpress.com/item/1005004296712406.html?spm=a2g0o.productlist.main.22.51047510BbVZoL&algo_pvid=cc429314-8a41-447b-91e8-817c69046e1e&algo_exp_id=cc429314-8a41-447b-91e8-817c69046e1e-21&pdp_ext_f=%7B%22order%22%3A%22117%22%2C%22spu_best_type%22%3A%22price%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21NZD%21644.33%21322.17%21%21%21380.36%21190.18%21%40210311cc17700912506964777e8d12%2112000036119929497%21sea%21NZ%21168182036%21X%211%210%21n_tag%3A-29919%3Bd%3A51d2aeff%3Bm03_new_user%3A-29895&curPageLogUid=Rufo3H7FJrhZ&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005004296712406%7C_p_origin_prod%3A

My own compressor that I use to fill a 10L bottle from which I then top up my guns is a water-cooled V-twin Tuxing. It has been nothing but trouble and I've spent far too many hours carrying out repairs and replaced a lot of parts. It recently cooked itself when the water pump failed so I've converted it to a 12V pump with a flow switch and relay so that the compressor pump will stop if there is no flow return from either another failed pump or a disconnected hose (which can happen if a head gasket leaks or fails). I bought it cheap off AE 2-3 years ago and suspect that it was a used pump housed in a new frame as it broke the inlet reed on the low pressure side in relatively short time. The debris that went through and did a fair bit of damage. I'll keep it though as I know it inside and out, the parts are plentiful and cheap and it does the job.

Even though we also have one of these at the club that is older than mine and has been pretty much trouble free, I wouldn't buy another or recommend it.

https://www.aliexpress.com/item/1005008047385036.html?spm=a2g0o.productlist.main.6.36bbPZoSPZoSl5&algo_pvid=7292a2ea-efc8-4744-8a30-8607240f9496&algo_exp_id=7292a2ea-efc8-4744-8a30-8607240f9496-5&pdp_ext_f=%7B%22order%22%3A%221%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21NZD%211321.74%211070.60%21%21%21780.25%21632.00%21%402101e81117700919567383460eaaa5%2112000052603309198%21sea%21NZ%21168182036%21X%211%210%21n_tag%3A-29919%3Bd%3A51d2aeff%3Bm03_new_user%3A-29895&curPageLogUid=swQshhBRxH1w&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005008047385036%7C_p_origin_prod%3A

My 10L tank is a carbon fibre/aluminium composite bottle (I have a dodgy back and the previous steel one was far too heavy for me to move around). I took it to the local fill centre once for the initial fill, but it's nearly a 90 minute round trip for me. When I saw how they filled them and the sad condition of the Fire Service BA carbon bottles I decided that I needed my own compressor.

This probably your best bet but make sure you get one with auto-shut-off. I'm not certain that this one is. If you only have a pistol, this will be more than adequate and a lot easier to use than a hand pump!

https://www.guncity.com/pcp-air-compressor-12v-250w-376381

Edited by KiwiTR6 - 15 hours 21 minutes ago at 4:39pm

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Diana 340 E-Tec .177
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Gamo 900 .22
Baikal IJ-22 .177
Crosman 2240 Custom .22
Brocock GP .22

Kris

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Posted: 15 hours 29 minutes ago at 4:31pm

The pistol I'm looking at is a Crosman 1701p has a 65cc tank.

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