It does have 3/8" studs. If it's a "slimline" bar, then a fellow will need the 'adapter plates' (actually PM105 bar plates) that Bryce is selling for $4.50 a set to keep the chain from digging into the saw.
Bryce has listed McCulloch 10-series MCCULLOCH labled 24" sprocket nose bars in the past. The listings expired without the bars being sold, so he may still have them. When his auctions run out, he doesn't immediately relist. That guy has a HUGE warehouse full of saw parts to list. I'll bet a person could contact him and luck out.
We weren't talking "McCulloch" branded sprocket nose bars (in specific) until Ron spoke up. Meatsaw was looking for a 24" SN bar (no mention of branding) and shop monkey incorrectly stated that 24" sprocket nose bars for these saws (again no mention of "McCulloch" branding) were much harder to find and expensive than 28" bars. I addressed that comment with a true statement (that 24" SN bars for 10-series aren't more expensive or rare than 28").
I mentioned D176 bars WHICH ARE a perfect match for 10-series McCullochs. I also mentioned Windsor TMX bars. Ron posed a NEW question/statement regarding "McCulloch" branded bars (in specific), then shop monkey made his revised "in conclusion" post, using Ron's NEW question to shore up his original shakey statement. Stupid, arrogant kids. There may not be any "McCulloch" branded SN 10-series bars (or other 10-series SN bars) listed on feebay RIGHT NOW, but they have been recently, and will most assuredly will be again. There are other sources besides feebay too (MoJim, and others). I have a "secret" source. I know of at least one other that a friend here can contact for me (it's local to him) if I ask. They're around...
Here's are some bars that my "source" (to be revealed to Ron in a PM) has/had. I now own the 24" Windsor TMX Speed Tip SN bar in the middle of this pic (with the black sharpie writing on it). It's on my PM700 now. The 20" bars above it and the 28" bar below it are McCulloch branded Windsor TMX Speed Tip bars (as were many of the ORIGINAL black/yellow and grey/black McCulloch branded 10-series SN's). I don't see the huge need for "McCulloch" branding on a bar that's actually going to be used in the wood. A show/shelf saw is another story. A fellow could always strip (or paint over) a new non-McCulloch branded bar and then stencil it with the desired logo. Sugar Creek has stencils...