Finished machining the Walther blank barrel today and installed it in the s1k. This rifle looks like it is going to be a winner.
With the .177 barrel I was getting 930's fps. with beeman FTS pellets, the .20 Cal. barrel is shooting 14.3 gr. Benji cylinders at 780 fps, and 11.7 gr. beeman Ramjets in the 870's. this is with the stock spring. rifle is just cleaned up and tared, and a needle thrust bearing in the custom top hat.
I have some JM springs and new seals conmming for it and also a 36 coil super spring I am going to try to fit in it.
Was not to bad installing the barrel, the gamo barrel is threaded and my lathe won't do metric threads, so I just reamed the threads out of the gamo pivot block with a 9/16 inch reamer and press fitted the barrel, worked just great.
Now I have to put a few pellets into some paper and see if I got the barrel in straight, if it shoots good. I will then take it back apart and cold blue the barrel, and do some serious testing with it.
Will keep you informed. By the way I talked to JM and he said he has a couple hundred of these Walther barrel blanks. I was asking about the tightness of choke of the barrel and then he told me about his supply of Walther .20 cal. blanks
