Yes, you should be able to swap braces.
The differences are mainly in the design and do not affect performance.
No, this brace will only fit pistol buffer tubes.
Yes, the SB Tactical SBM4 Stabilizing Brace will work with the SAR 109T.
No, these are made to go onto an unobstructed buffer tube.
Please email us at techsales@opticsplanet.com so we can further answer your question.
The SBM4 is a pistol tube mounted brace, but as long as the pistol tube you are mounting this too is a carbine length tube, then it will use the same buffer weight and same buffer spring. But the weight and spring are dependent on the tube and not the actual brace.
This is a pistol buffer tube mounted brace. It has one position and cannot be adjusted for position on the tube.
The SBA3 is for platforms capable of accepting a mil-spec carbine extension, and the SBM4 is for platforms equipped with an AR-style pistol buffer tube. You would need to confirm you have the proper AR style pistol buffer tube for installation.
Yes, this should work with the Freedom Ordnance FX9P4 AR Pistol.