Thread: 930 spx chamber/gas ports
30 January 2012 21:13 #1Member
- Join Date
- Jan 2012
930 spx chamber/gas ports
Just got a 930 SPX Blackwater edition – really like the shotgun but like many during my first time out with it the low power Winchester/Federal shot shells would occasionally stove pipe/half eject. Then on round 75 or so one stuck tight in the chamber and the joy was over - I had to disassemble, manually release the extractor with a small screw driver and then use a cleaning rod to tap the spent case out of the chamber.
Looking at the chamber I noticed how rough it was, that definitely would cause issues with extracting “lower power rounds” (Federal/Winchester value pack) – overcoming the extra friction. Had the same issue with my RRA 458 SOCOM scratch up the brass really bad and fixed that by polishing it up with my dermal/polishing wheel and Flitz – it now runs extremely well. So I broke out the equipment and polished up the first 3/4 of an inch of the 930’s chamber – it came out pretty nice (picture below). You can see the difference between the factory surfacing and polish. I think this must be why they want you to cycle a lot of high power rounds through it – smooth out those chamber ridges.
Back out to the range and 150 rounds later things worked pretty good overall. Now I could ONLY get the 930 to stovepipe or not eject the "low power" spent shells (about 80% of the time) by “limp-wristing” the shotgun while firing (letting it float). No more of the stuck case thing! I noted that the action would cycle back 1/2 to 3/4 of the way when letting it float. Very close to ejecting but not quite there…
So the next thing to inspect was the gas ports – picture below (there is a little loose debris in the right port). The right one measures 0.143” diameter and the left is 0.141” diameter. I am thinking about drilling them both out on the mill with a #27 drill (0.144”) which increases the total port area by ~3% - not very much. The next standard (easy) option up would be a drill #26 (0.147”) which provides an increase of ~5% for one port and ~8% for both. I would of course debur the port when finished.
My question – has anyone increase the ports on one of these 930’s? If so what sized did you go to and what were the results?
Last edited by starfury; 31 January 2012 at 06:43.