N/A On average, are PCP semi-autos more complex and less reliable than side lever?

[Ultralight]

I'm told that PCP semi-autos are more complex and less reliable than side levers.

1. Is this true?
2. On average, how much more complex - if there is a rough percentage.

For example, lets compare the Hubens K1 vs Daystate Revere or something along those lines.

Thanks in advance for any insight.

 

[BSJ]

Is there such a thing as a reliable simi-auto?

 

[Ratzy]

They require a method of loading the next round and setting the action.

A lot do it with a plug in the end of the shroud to capture some of the air from the barrel. The plug has a connecting rod back to the action. A gear reduction then connects to the pellet pusher and loads the next round.

 

[Ratzy]

Is there such a thing as a reliable simi-auto?

I have 3 out of 4 and #4 is because I broke it.

 

[AlanMcD]

I'm told that PCP semi-autos are more complex and less reliable than side levers.

1. Is this true?
2. On average, how much more complex - if there is a rough percentage.

For example, lets compare the Hubens K1 vs Daystate Revere or something along those lines.

Thanks in advance for any insight.

Clearly the Huben K1 is far more complex than a Daystate Huntsman - it probably has close to three times as many parts in it, if you add up all the individual parts that make up the gun (lots of the "parts" are assemblies of multiple parts).

That said, I don't know that it is necessarily less reliable, at least on an equivalent shot count basis. I have a Daystate Air Ranger (similar to the Huntsman, but bolt action and not side lever) and a Huben K1, and although the Air Ranger has seen a lot of shots, the Huben probably has 3-4 times as many on it - maybe 5,000 shots on the Daystate and approaching 20,000 on the Huben. Setting aside issues caused by me, the Daystate probably had one failure and the Huben maybe three, so not so dissimilar. Both are very precise and robustly designed mechanical systems . . . .

 

[Ratzy]

They require a method of loading the next round and setting the action.

A lot do it with a plug in the end of the shroud to capture some of the air from the barrel. The plug has a connecting rod back to the action. A gear reduction then connects to the pellet pusher and loads the next round.

They can be unreliable. For example adding a moderator to a Hatsan Semiauto will make the rifle stop indexing (loading the next round). To fix this, mostly, requires changing the return spring in the shroud. But generally the Hatsans will occasionally fail to index even with the modified return spring.

A tedious process of adjusting return spring, hammer spring and regulator pressure can produce a setup that is almost 100% reliable. Unfortunately the process appears to be unique to each gun based upon a sample of 2.

 

[daddypaddy]

They require a method of loading the next round and setting the action.

A lot do it with a plug in the end of the shroud to capture some of the air from the barrel. The plug has a connecting rod back to the action. A gear reduction then connects to the pellet pusher and loads the next round.

really? that way of cycling the next pellet sounds like a nightmare. i’ve only ever dealt with the huben k1 and its been super reliable.

 

[Ratzy]

Blow back cycling?
Using expended gases to drive the process. Kind of the standard methodology.
Only difference in how Hatsan does it vs a PB is where they capture the energy. PB capture it in the breech/recoil. Airgun at the end of the barrel.

 

[daddypaddy]

Blow back cycling?
Using expended gases to drive the process. Kind of the standard methodology.
Only difference in how Hatsan does it vs a PB is where they capture the energy. PB capture it in the breech/recoil. Airgun at the end of the barrel.

huben k1 doesn’t use the end of the barrel. the cycle mechanism happens on the left side of the block just in front of the fixed magazine.

 

[Mr.H]

Can Western owners chime in on this thread??

 

[cavedweller]

I'm told that PCP semi-autos are more complex and less reliable than side levers.

1. Is this true?
2. On average, how much more complex - if there is a rough percentage.

For example, lets compare the Hubens K1 vs Daystate Revere or something along those lines.

Thanks in advance for any insight.

your questions are going to get vague guestimates.
simple = the more complex the mechanism the less reliable = more moving parts = more things to go wrong.
I own a steyr pro x 10 semi auto 10 round that uses a removable magazine. in 3 years it has never not worked.... i just run out of air because i can shoot it so fast.

 

[Ratzy]

your questions are going to get vague guestimates.
simple = the more complex the mechanism the less reliable = more moving parts = more things to go wrong.
I own a steyr pro x 10 semi auto 10 round that uses a removable magazine. in 3 years it has never not worked.... i just run out of air because i can shoot it so fast.

Yep, old test engineering rule:
As points of failure rise the odds of failure rise with it.

More complex system has a greater chance of failure.

Complexity and points of failure:
Single shot tophat guns.
Break barrel guns.
Single shot poppet valve guns.
Magazine poppet valve guns.
Semi and Full Automatic pcp guns.

 

[AlanMcD]

Can Western owners chime in on this thread??

I also have a Sidewinder to compare to the Huben K1, both in .22 caliber. I would say that it is probably similar in terms of complexity, and maybe close in terms of reliability, but I have not shot it anywhere near as much. I do feel like the Huben is the better made gun of the two - it just feels more solid. I did have one failure already in the mag advancement mechanisim on the Sidewinder, and AoA sent me the part to fix it. That same system has never failed yet in my Huben, but I have had a few other minor issues as the shot count went over 10K.

Both have semi-auto mechanisms that are pretty rock solid - they do not work off any vented air so there is no impact of adding or removing moderators on them. They do involve the use of air pressure though, but in an ingenious way (which Huben probably invented and then everyone else copied/modified). The magazines have a toothed drive mechanism, and the teeth are indexed after each shot by an internal spring and air-driven piston assembly. The piston is exposed to the air pressure in the area of air that I will call the "shot chamber" - this is the air that propels the projectile out the mag and through the barrel when the gun is fired. Upon firing, the pressure in the "shot chamber" falls to near zero as the air is vented on the shot (it flows until the closing valve trips limiting the air that can flow on the shot). When the pressure drops, the spring takes over on the indexing mechanism driving the piston that advances the magazine. After the closing valve trips and the firing valve resets, the pressure in the shot chamber rises again and this drives the piston back to it's retracted state. It works great and can be very robust. Here is a video demonstrating it - you can sort of see part of the advancement mechanism in it.

 

[IKnowNutin]

your questions are going to get vague guestimates.
simple = the more complex the mechanism the less reliable = more moving parts = more things to go wrong.
I own a steyr pro x 10 semi auto 10 round that uses a removable magazine. in 3 years it has never not worked.... i just run out of air because i can shoot it so fast.

Ditto! The mags are cycled with spring tension. No bleed air required. I've put a few thousand pellets through mine and it has never failed to cycle. It just works and is very accurate.