Personally, I would advise taking the Ruger SR9 and break it down and break down the Security 9. Now look at all the Steel in the Chassis, then compare. What gun do you think will last much longer and built so much better?
Now compare prices. Then shoot both. I doubt the Security 9 will be as accurate are as mild shooting as the SR9 series.
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Red marks steel inserts.
courtesy Gunsumer reports