Lees Precision Engineering have sent over details of a new item they have in production:
Laser Cut Magazine Shims Now Available For Tokyo Marui & KJ Works Glocks
LPE Magazine shims are one of the simplest and cheapest upgrades available for ‘gas in mag’ guns on the market today. Magazine shims are placed under the gas router on the top of GBB & NBB magazines to push the rubber seal up so it forms a better seal with the loading nozzle which can give some of the following improvements in performance :-
Better gas efficiency
Improved shot-to-shot fps consistency
Increase in power/fps
Increase in felt recoilInstallation is generally very easy and reversible requiring no modifications to the gun or magazines, in most cases only requiring the feed lips removing and a single shim being placed under the gas router. Please note that more pressure on the feed lips will be required in some cases to reinstall retaining pins and care should be taken not to damage the pins or feed lips themselves.
Laser cut in the United Kingdom from engineering grade plastics.
http://www.leesprecision.co.uk/laser-cut-mag-shim-pack-of-4-tokyo-marui-kj-works-glock-series.htmlTrade and wholesale prices available for distributers and retailers, please contact for a trade price list.