DIY is pretty easy, just grind or saw off 1/8 to 3/16" and round the end a little then polish. 

I have one Pietta and changed the base pin to Uberti.

For those shooting 13 grains of Red Dot.  What  bullet weight are you using and range setting are you using on the rear sight?

Have you tried these guys yet ?

https://www.vtigunparts.com/store/shopdisplayproducts.asp?id=23&cat=Uberti+1873+Cattleman+SAA+and+Target

Yes, out of stock. I expect I'll order from them eventually, though, if the DIY scheme goes poorly.

Does the Uberti Bisley model have a one piece back strap/trigger guard?

Rather than the typical 200 grain flat point CAS .44 Russian loads, I used Bear Creek's 246 grain, conical round nose .44 Russian/Special bullet over 5.3 grains of Unique.  That is listed in Lymann as a factory duplication load.  That should smack the plates with authority.

When I shot in NCOWS I used the Lyman 429251 bullet with BP for my 44 Russians in the '72 OP.  Did that only because I never could put my hands on the Lyman 429184 bullet mold listed as the 'regular' 44 Russian bullet.

Have fun with those revolvers.  I will own one someday, just not this soon.