NEED SOME INFO BEFORE I PURCHASE

[roryhunt]

kcurrie - 4/12/2009  4:58 PM



To make the gun MUCH smoother shooting take it apart and move the guide/piston to the back rather than the front-- it won't kick nearly as much if you do that.

 

 

Cool.  Is there anything involved in doing that that a novice can't handle?  I am mechanically inclined, just brand new at this stuff.  I don't need any special tools do I?

[kcurrie]

Well, generally people recommend using a spring compressor to take it apart.. The 512M's spring isn't under a load though so it's not really necessary... as a matter of fact I once talked somebody through it over the phone and it's pretty simple. Search the forums and you can find some further details on it. All you need is a tool like a punch or screwdriver to knock out a pin and a screwdriver to take off the stock.

[birdmove]

My air rifles are all in .177 caliber. I've never fired a .22 cal airgun. Is a .22 louder when firing? I imagine it's louder when hitting a pellet trap? Quieter guns are important to me, since I don't want to lose the ability to shoot in my back yard. Also, it keeps things simpler to just have to keep pellets of one caliber in stock.

    jon

[airgunandy]

The MP512-M is a sweet little rifle. With a little TLC it's even better! I have one in .22 caliber. Been using mine in the GTA open rifle target matches.

[kcurrie]

I don't think there is anything that makes a .22 inherently louder than a .177. My 512M isn't very loud at all actually anyway.

[elmer fudd]

Generally just slower and harder hitting.   It's still got the same power plant and that's mostly what determines how loud it is.   It might even be a little, (very little), bit quieter since a .22 barrel will have a larger volume and there should be a slightly smaller blast of air behind the pellet when it exits the bore.   Any difference will be pretty trivial though and nothing your neighbors would notice.   Heck, Gamo put a baffled MuzzleBrake on the end of their Whisper and most people say that even that makes little to no difference in it's report.   The main source of noise from a spring gun comes from the spring and the piston.

[roryhunt]

kcurrie - 4/12/2009  4:58 PM



TTo make the gun MUCH smoother shooting take it apart and move the guide/piston to the back rather than the front-- it won't kick nearly as much if you do that.

 

 

Sorry to keep bothering you, but I took the gun apart, but am having trouble understanding what you mean by moving the guide/piston from the front to the back.  I tried searching the forums here, but had no luck finding a more detailed walkthrough.  I would love to make this gun a bit smoother firing, and I am going to do the trigger mod on that russian page you found.

Again, sorry if I am bugging you, just new to all of this.

[kcurrie]

The spring guide is the thing that goes inside the spring-- by default it's in front of the spring. Move it behind the spring and it will cut down the recoil substantially.

Don't worry about asking questions-- that's what we do here :-)

[roryhunt]

With the spring resting against the fat part of the guide, outside of the spring, or the fat part facing the but of the gun, with the spring resting against it?

[kcurrie]

Not sure what you mean there... if you take the spring out there is a spring guide/piston right in front of the spring-- move it to the back.

that would be part #6 here I believe (a little hard to see in the diagram) [url]http://www.pyramydair.com/site/manuals/mp512/ [/url]

BTW here's talk about this on this forum:

http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=7878&posts=21&highlight=512M%20guide&highlightmode=1#M58679

[Jaymo]

The first thing I did to mine was strip it, clean it, polish the piston and the spring ends and swap the spring guide over to the rear of the spring. Made a big difference in the amount it jumped when firing. I lost a wee little bit of velocity due to lower effective piston weight but it was worth it.
I also replaced my piston seal because mine wouldn't stop dieseling. European American Armory carries parts for the MP512M. I need to replace my breech seal, also. I think I'll make it myself.

[roryhunt]

Alright, I did the guide mod, and it does shoot a lot smoother.  Should I wrap the piston head in teflon tape as instructed in the other discussion, or does that not impact the power that much?  If I do, How tight is too tight to make the seal?  I guess i mean, how hard should it be for me to push the piston in?  

Also, how hard is a trigger mod on this gun?  I don't understand the terminology of "grinding the mushroom" and the trigger on this thing is a bit stiff.  I have a nice dremel set, and imagine I could grind and hone pretty minutely if needed.

Again, thanks so much for all your help.