Morini CM 162 EI Velocity Which Way To Decrease?

[CraigB5940]

I just got a used Morini CM 162 EI (not a short) and I suspect the prior owner cranked the velocity way too high, I only get about 120 shots per 200 BAR fill. Can anyone tell me which way is which on the velocity adjustment screw? I don't have a chronograph and I don't want to go crazy in the wrong direction until I can get use of a chrono for my final testing.

The reason why I suspect tampering is that the trigger was set to 60 grams and set at single stage mode! My prone rifle is fine with a this on the second stage but someone was a fool to shoot a pistol like this.
This was measured on a Lyman digital scale. I got set it back to 500g two stage and this thing is a dream come true after learning how to shoot with a Baikal 46-M during the past 2 years. I am very happy indeed!

[Rover]

Sounds about right to me, unless you were using CO2.

In any case, just turn the adjustment screw widdershins to decrease velocity.

[David M]

Clockwise to increase, Anti-clokwise to decrease (about 5-8 m/s per turn).
Find a chono and set it between 145-152m/s.

[CraigB5940]

Thanks all

I ordered a chrono last night. Until I get it, and 2turns to the left has given me less muzzle flip so I think somebody was playing for max velocity.

[Rover]

Well, the air is free.

That's why some of us have big noses.

[Silvershooter]

I ordered a chrono last night. Until I get it, and 2turns to the left has given me less muzzle flip so I think somebody was playing for max velocity.

Let us know the velocity, I turned mine (standard length) down 1 1/2 turns from factory setting, it handles a lot better.

[CraigB5940]

OK, I got my chrono, and it says that the 1.5 turns lower I took it got me to 502 fps average for 10 shots.
I don't know where it was at 1.5 turns higher other than the muzzle filp was obvious and wrong.
1.5 turns got me to where the muzzle was stable and I like it where it is.

[CraigB5940]

Correction I took it down 2 turns from where it was not 1.5. And I don't know if that was the factory setting since the prior owner botched the trigger adjustment I bet he fooled with velocity too.

[David M]

Now set it up in a machine rest and group test while also using the chrono,
I found that as I increased and decreased the velocity that the groups were
nodal.
I had a tight group at about 485 fps, then the group opened up a little only to
re-close about 520 fps.
I set the velocity for the lower node at 485 fps.

[Gwhite]

Reviving an old thread...

I sent my Morini out to a reputable service shop for a general cleaning & overhaul. When it came back, I noticed it was using a lot more air than it used to. In fact, over time, I found I could only get 100 shots out of a cylinder before the cocking arm locked. It also seemed to have more muzzle flip & the "clank!" of my pellet trap sounded a lot louder.

I finally got around to checking the velocity, and they had cranked it up to 575 fps! I just tried to adjust it down to 500. The first two turns of screw #162077 dropped it 50 fps to 525 fps, which was about as expected from prior posts. I figured another turn would get me to 500. We'll, it appears the screw has backed out to the point where it isn't doing anything anymore, because it's firing at 520 fps now. The screw is also sticking out the back far enough I had to relieve the grip to provide clearance.

So, short of going into the regulator (which I really don't want to mess with), is there any way of further reducing the velocity? Screw #162031 for example?

162EI Velocity Adjustment.gif (37.82 KiB) Viewed 4333 times

As an aside, when the pistol was returned, the front sight was visibly tilted. Despite being shipped in its factory case, I figured maybe it had gotten knocked sideways in transit. When I loosened up the front shroud, I couldn't rotate it far enough to quite get the sight level. It's close enough that I can largely ignore it, but its annoying. Given that they messed up the velocity that badly, I'm wondering if they took the barrel off and re-installed it cockeyed. I haven't tried messing with the two screws that hold the barrel to the frame. Are there any cautions about trying to adjust the barrel position with those?

Thanks!

[thirdwheel]

Sorry cannot help with the velocity being too high, but yes just loosen two screws on barrel fixing and turn a bit and re-lock but keep pressure inward to keep pressure on the first "O" ring on the start of the barrel.

[David M]

So, short of going into the regulator (which I really don't want to mess with), is there any way of further reducing the velocity? Screw #162031 for example?

Part #162031 is Not a screw, it is the spring guide.
If you back the velocity screw #162077 off enough then the spring guide will be against the frame backstrap and no further reduction is possible.
The only other way to reduce the velocity further will be to change the hammer spring #162030 to a lighter coil of the same length.

[Gwhite]

Thanks for the replies. It looks like the regulator is putting out too much pressure. That appears to be a fixed assembly, and not something that is "tunable" (at least not easily).

I'll shoot it as is for now, after I try to straighten out the sight. I can order a spare spring or two and investigate either shortening it , or finding a weaker replacement.

I use a Hill pump, and I'm hoping I can get a lot more shots for my efforts at 520 fps.

[David M]

It looks like the regulator is putting out too much pressure. That appears to be a fixed assembly, and not something that is "tunable" (at least not easily).

A easy check for the Regulator is to note the tank pressure that the lockout cuts in at, should be about 80 bar.
Adjusting the regulator needs a workshop and a gunsmith who knows what he is doing.
Its not the sort of job I will detail on the net.

[Gwhite]

The lockout tends to occur at what I consider a slightly high pressure (90 bar?). Does that make sense? It's been a while since I ran one down that far. The impression I had was that it was high enough to be aggravating the short shot count problem I was having with the velocity over-cranked.

It's also a bit hard to tell because the tank gauges are pretty inaccurate. When I have access to fill from a SCUBA tank, it has a high quality gauge on it. 200 bar on the tank gauge can be +/-20 bar on the cylinders.