Looking for mags that are smaller, better for shooting prone at competitions. I was looking at the short s&w mags but I can’t find any. Any alternatives

The black dog 10rd mags are somewhat short.  Not quite as short as the 10rd S&W to my recollection, though.

I believe the 15rd mags are the same length as the 10rd blackdog mags.  They have worked great for me.  The harris is a 6-9 swivel model and the legs are not extended.  My son shooting it at 50yrds.






Same 15rd black dog mag on a 4.5"build I did recently (using a very short Troy grip)

Atchisson patent pattern 10 round mags (as sold by J.A. Ciener) are short and all steel.  Not compatible with McFadden loader.

Disclaimer:  I own a Atchisson patent pattern 30 round mag (as sold by J.A. Ciener), not the 10 round which is a cut down version of the 30 rounder.
I have no affiliation with or financial interest in any vendor or manufacturer; and I am not a competitive shooter or a blogger who receives any form of compensation for endorsements or favorable public or private comments.  Use of vendor and/or product brand names, if any, is for informational purposes only.

Best of luck.
MHO, YMMV, etc.  Be well.

@balloo93
Off topic, but can you share how you've got that brace attached?

@ar15-joe KNS rail adapter

I fed some paracord through the unused rail section for a single point sling.

Nice.  Thanks.

Both the 10 round and 15 round Black Dog Machine magazines are the same length as a standard 20 round 5.56 magazine. They work fine for shooting from a bench with rest or bipod and for shooting prone.