8.1.8 Non-IDPA-Legal Features and Modifications for All Divisions:
B. Add-on weights. This includes (but is not limited to) weighted magazines, tungsten guide rods, brass magazine wells, weighted grips, and weighted grip plugs.
22.214.171.124 SSP Permitted Modifications (Inclusive list):
Q. Aftermarket magazines may be used provided they do not weigh more than 1.00 oz. over the same capacity factory magazine.
R. Aftermarket magazine base pads may be used provided they do not make the magazine weight more than 1.00 oz. over the same capacity factory magazine.
S. Magazine base pads may be modified by reshaping, texturing, or adding bumper pads provided that they do not make the magazine weigh more than 1.00 oz. over the same capacity factory
T. Magazines that are longer than stock may be used provided they meet all other division requirements.
Onto the question:
The weight difference between factory glock magazines and the Magpul replacement magazines averages just under .17oz.
Can 0.25oz be added to the Magpul magazine in the form of lead tape under the baseplate or would that qualify as a weighted magazine?
The only issue I've run into with the Magpul mags is that they dont always drop free, but if I add a little weight to the bottom they work great.