First off CTD why ?!
And what caliber is this ?
I think if it newer and sates E2 the mags should work old mags not so much I would say ...
"s SIG Sauer has slowly begun adopting the E2-style grip system across the P229 model range in 2011—a move similar to what is also happening to the larger P226—they have also begun using the .357 SIG/.40 S&W spec frame dimensions for their factory 9mm P229s, presumably to streamline the number of variations in parts needed to be kept in inventory. Although the manufacturer has announced that older-configuration magazines will continue to operate in the new receiver configuration, SIG Sauer has nonetheless revised new P229 9mm factory magazines to a design that is specific to the resized magazine well of the newly reconfigured receiver/frame. As a consequence, the newer magazines are not back-compatible, due to their larger diameter."
Also I dont know what CTD is charging but midwya USA has the 229 mags factory for 40 bucks plus like 5 bucks shipping and I think still free shiping for over 150 http://www.midwayusa.com/find?userSearchQuery=229+mags+
I rather buy from Midway or somethiner other company then CTD. CTD threw us gunners under the bus imop