Page 1 of 3

AA S400 MPR FT questions

Posted: Wed Sep 14, 2016 7:45 pm
by Mtl_Biker
Hey Guys,

I just received my new (to me) Air Arms S400 MPR FT rifle. It looks like it's brand spanking new with not a single mark on the stock or barrel. Don't know how it shoots yet, and I'll have to wait another 3+ hours for the staff to go home before I can actually try it. (Gonna be a LONG afternoon!)

I do have some questions that I couldn't find answers to in the manual I downloaded...

First of all, is it possible to dry fire this rifle without discharging air?

Second, the trigger first stage has absolutely no resistance at all. It just flops loosely. The manual says that screw "E" adjusts trigger pull weight but it seems to affect only the second stage pull weight. It's almost as if a spring or something was missing from the trigger assembly. Is this normal?

(I like at least some resistance on the first stage, and this lack of feel would be annoying.)

How many good shots should I get per cylinder fill?

Thanks for any help.

Re: AA S400 MPR FT questions

Posted: Wed Sep 14, 2016 8:35 pm
by TenMetrePeter
If the gun is not cocked the trigger will be floppy. When cocked it feels completely different.

you can't dry fire without discharging air.

P.S. There is an article by Rowan Engineering that contains first and second stage adjustment for this trigger. The MPR trigger is very similar to the S400 article photos except the trigger spring is captive and doesnt come out with the guard (at least mine doesnt)

http://www.rowanengineering.com/pdf/S40 ... struct.pdf

Re: AA S400 MPR FT questions

Posted: Wed Sep 14, 2016 9:29 pm
by Mtl_Biker
TenMetrePeter wrote:If the gun is not cocked the trigger will be floppy. When cocked it feels completely different.

you can't dry fire without discharging air.

P.S. There is an article by Rowan Engineering that contains first and second stage adjustment for this trigger. The MPR trigger is very similar to the S400 article photos except the trigger spring is captive and doesnt come out with the guard (at least mine doesnt)

http://www.rowanengineering.com/pdf/S40 ... struct.pdf


That's great! Thanks so much, Peter! (Have I seen you on TargetTalk?)

Obviously (since I haven't actually shot the rifle yet) I haven't been able to test fire with the trigger cocked. But it's the first gun I have on which it appears not to be possible to evaluate the trigger without actually taking a shot. On my Weihrauch spring rifles, I do the adjustment with the trigger mechanism out of the gun, and with my Steyr pistol, dry fire lets me test/adjust it. So it appears I've been worrying about it for nothing. I only have about 45 minutes to wait until my staff go home and I can actually try the rifle (and trigger).

Thanks for the help, and I'll be back if I can't get it working right.

Cheers!

Re: AA S400 MPR FT questions

Posted: Wed Sep 14, 2016 10:24 pm
by TenMetrePeter
I have posted a few times on Target Talk but no more. Not comfortable. This place however is like a cosy pub!

I belive someone on here described the comforting trigger rattle as reassurance it wasnt cocked!
Ii is a superbly adjustable trigger once you understand it but Air Arms advise to leave well alone. See how it goes

Re: AA S400 MPR FT questions

Posted: Thu Sep 15, 2016 12:43 am
by Mtl_Biker
TenMetrePeter wrote:I have posted a few times on Target Talk but no more. Not comfortable. This place however is like a cosy pub!

I belive someone on here described the comforting trigger rattle as reassurance it wasnt cocked!
Ii is a superbly adjustable trigger once you understand it but Air Arms advise to leave well alone. See how it goes


If this is like a cozy pub, I'll have a Guinness please. :)

I finally got to shoot the rifle and the trigger does indeed feel much different when the gun is cocked. Nothing to worry about. Sorry to have bothered you all with such a novice question. Very interesting though that the behaviour is so different.

Love the gun!!

But I am finding the cocking to be rather stiff/difficult. Compared with the CZ 200T (AA S200T) I just sold. This requires a REALLY hefty pull to cock. And there's something I don't understand... there's an "o"-ring on the cocking shaft:

Image

Is this normal? Shouldn't it be INSIDE somewhere?

Or am I worrying again for nothing.

Maybe I'll have an other beer. Please. :)

Cheers!

Re: AA S400 MPR FT questions

Posted: Thu Sep 15, 2016 6:12 am
by Raj
The o=ring there is normal. It stops the bolt jumping when the shot is taken.

Re: AA S400 MPR FT questions

Posted: Thu Sep 15, 2016 7:11 am
by TenMetrePeter
re cocking, wrap your thumb round the left side of the bolt and get 2 fingers close in so you are doing a straight pull on the shaft. I wouldnt hang onto the knob end to pull the bolt as it applies side pressure. And a smear of moly gun grease on rhe shaft helps. 20 years since I had a 200 but I think it was lighter.

Re: AA S400 MPR FT questions

Posted: Thu Sep 15, 2016 12:56 pm
by Mtl_Biker
Raj wrote:The o=ring there is normal. It stops the bolt jumping when the shot is taken.


Thank you. That's reassuring. It just looked somewhat strange to see it there on the shaft and not doing anything.

Re: AA S400 MPR FT questions

Posted: Thu Sep 15, 2016 2:34 pm
by Mark112
Raj wrote:The o=ring there is normal. It stops the bolt jumping when the shot is taken.

... and the anodising being worn away by the bolt.

Re: AA S400 MPR FT questions

Posted: Thu Sep 15, 2016 6:25 pm
by bripard
You will love the gun. I have one, and it is one of the most accurate guns i have shot. Mines a keeper,