question about AV-46m (IZH-46m)

[gnm]

Hello, new user here.

I bought a new AV-46m. When I extend the pump handle, it correctly opens the bolt and pushes the bolt upward. However, as soon as I finish pumping, the bolt falls down. It does not lock - just falls down. So I open it and click it into the vertical open position with a finger, load a pellet, and close the bolt.

Is there something I can adjust so the bolt stays in open position after pumping or do I have to send the pistol back?


I posted the same question on rimfirecentral and got the following reply with a very useful video:

"I don't know the answer other than sending it back GNM but here's a video so members can see what you're talking about. Fast forward to 3:50 to see how it's supposed to work.

https://www.youtube.com/watch?v=UD_nyeiuw8U "

Thank you.

[Gwhite]

Make sure you are moving the cocking lever ALL the way forward and up until it stops. What you describe can happen if you only open it far enough to unlatch the bolt and pump it. You may just need an extra little push to pop the bolt up until it latches.

[gnm]

Yes, that is exactly how I do it.

It seems that the detent that holds the bolt in open vertical position is only fully engaged after the end of the pumping stroke. So here is the sequence: extend pump handle all the way forward, breach is open and bolt is pushed into vertical position, complete pumping stroke - the bolt falls down during stroke, the detent is fully engaged after the completion of the stroke. Manually bringing bolt back up and "click into" the detent.

[Gwhite]

The pump handle needs to go UP at the end of the stroke to latch the bolt, not just fully forward. If that doesn't work, but the bolt will stay up when it is raised manually, then the linkage between the pumping hardware and the bolt isn't quite long enough for some reason. It's been a long time since I was inside one, so I'm not sure what the most likely culprit is.

There is a flat strip of metal under the barrel that goes back to the sliding breech block. There is a screw on the right side of the breech block that connects to another piece that go to the rear under the grip that actuates the bolt. If one or more of those pieces is a bit short (or a combination of all three), then it won't quite lift the bolt far enough to latch.

It sounds like it's still under warranty. I'd there's nothing obvious wrong (like the screw on the side is loose or missing), I'd call Air Venturi and see what they suggest.

[brent375hh]

FWIW,
I have an old IZH. It always seemed like quite a strain on the system to cock using the pump lever. I have always manually cocked the hammer, then pumped the chamber, loaded, closed the breech and fire.

[-TT-]

My AV-46M does not cock when extending the pumping lever. It raises the bolt about halfway, but nowhere near fully cocked, the air valve typically isn't even closed.

I just cock it by hand, leave it raised, then load and close the bolt. This has the side benefit of keeping the bolt seals away from the port, so they don't go flying if the air discharges (something that inevitably seems to happen if I get distracted).

[Oldnslow]

I do what Brent does (I think he suggested it in a post a few years ago): cock it by hand, then pump. I've even removed the thin lever that connects the pump linkage with the cocking lever, so I'm not tempted to use it that way.

[gnm]

So my gun cannot be cocked by hand: the detent is not holding the bolt/cover in upright position. The only way I can fully cock it is by doing a complete pump, then manually cocking it.

I think it means that my gun is defective.

[Vadym]

When cocking the lever, the bolt of my pistol obediently popping vertically, but I have to hold it with my finger from falling. If this is not done, then the bolt falls after compression and it becomes very difficult to open it separately.

[Vadym]

It seems to me that the reason is to maintain the correct form of '17' part. Over time, its edges wear out, which causes the bolt to drop

[brent375hh]

For those with cocking issues:

Can you cock your hammer to dry fire?
If yes, will the lever stay up after you have cocked it?

[Vadym]

1. Yes.
2. No without compressed air and yes if valve under air pressure.

[brent375hh]

FWIW my early non- M 46 is able to cock and it stays vertical until it is pushed down to fire, whether the chamber is pressurized or not. I wonder if all AV-46M have a slight change (defect) from the IZH version?

[gnm]

Same as Vadym's: my pistol can be cocked to dry fire but the lever will only stay up if valve under pressure.

I already saw 2 other AV46M that do not have this problem. So I believe that it is an individual pistol problem.

[UnGe]

If a gun is new, probably something else is going on, but for the old one - I asked the same in https://targettalk.org/viewtopic.php?p=325955

For me this narrowed down to spring #13. If I manually expand it, the problem fixes for awhile, but reappears pretty soon, meaning that the spring is just worn out.
Somebody advised to cut spring #12 to mitigate the problem - helps (for some time) too, but I'd not advise this, as it makes breach locking less reliable.

[Vadym]

FWIW my early non- M 46 is able ...
... AV-46M have a slight change (defect) from the IZH version?

I have two IzH-46 pistols both the 1990 early Soviet version without M - one of them is in "like new" condition and its shutter works as it should - it rises to 90°, does not fall by itself, the shot safety is activated when the bolt is not closed. And another pistol after a long time shooting in a sport club - it does not have a safety and its bolt opens at 45° when cocked and falls if it is raised by hand, but stays upright when there is air pressure in the valve. This is me - the reason, as it seems to me, is the wear of valve group parts or, in the case of AV-46, the low quality of parts processing in modern production.

[gnm]

Update: I sent my pistol back and received a replacement that functions properly.

The new pistol is averaging 445 fps with Excite 7.4 gr and about 405 fps with vogel merlin match plus 8.2 gr.

Interesting that the trigger on the replacement is much heavier than on the original, both are brand new from the factory without any adjustments yet. I will adjust it later after I put the new trigger blade on it.

Thank you all for your help.