osp/gsp

[Bill A]

Hi,

Anybody know if an OSP 2000 upper (barrel/slide) will fit on an older (mid 80's) GSP lower (frame/trigger unit)?

Bill

[Fred]

Bill,

An OSP 2000 should fit right on a GSP frame, unless the GSP frame is a much older model. Mid '80s should be OK. However, there will be a big gap between the rear of the OSP top end and the GSP grip. You can fit an OSP grip to the GSP frame to eliminate the gap, and give you a higher hand position with a more raked grip angle. What are you trying to do with this combination?

HTH,
Fred

[lionheart]

There are some other strange things though.

I have some .22 lr that wont cycle the slide reliably in the GSP. so I tried the OSP receiver with the .22.r barrell and the .22lr mags wont lock into the frame.

In other words, the .22lr mags won't fit into the gun if the OSP reciever is on it.

[Fred]

In other words, the .22lr mags won't fit into the gun if the OSP reciever is on it.

When I converted my OSP to .22LR I found the thing. The feedramp of the OSP receiver was just slightly too long to allow the GSP mag to seat properly. I ended up filing a little off the front of one of my GSP mags in order to allow the conversion to work.

However, I believe that this is not always the case. Sandy Santibanez, who more or less pioneered this type of conversion, told me that he never had this problem, nor have I heard anyone else mention it until now. So I would suggest checking the spot I described, if you want to pursue the conversion.

Warning: if you just stick a .22LR barrel on an OSP receiver without beefing up the recoil system, pretty soon your receiver won't be good for anything.

HTH,
FredB

[lionheart]

I did notice the difference in the mags.

My real problem is that I would need a lighter recoil spring to shoot certain ammo.

With the move to a standard pistol for rapid fire, this might be desirable.