Quick Question about my MAC-10/45

[MrRuffGunz]

I have just purchased a totally new to me full auto Mac 10/45. Trying to figure out if the barrel is threaded 3/4-10 or 7/8-9? Would a Micrometer work best? Reason I ask- I want to put my Bowers VERS 45 silencer onto the 9mm Lage upper which is currently threaded 1/2-28* I don*t know what the original thread size in and I*m getting mixed info as to which one I have* This is just a quick question* don*t attack* I guess the thread size will either be .750 (for 3/4 -10) or .8750 (for 7/8-9)* TPI of 10 vs 9??Just need to know what I have to measure* I don*t want to Order the wrong adapter

[Daycrawler]

I guess the thread size will either be .750 (for 3/4 -10) or .8750 (for 7/8-9)* TPI of 10 vs 9??Just need to know what I have to measure* I don*t want to Order the wrong adapter

Separate the barrel/upper and go to a hardware store. Find the correct size in a nut. Once you have established that, order the correct adapter.

[JoshIronshaft]

You can use calipers to measure the outer diameter and thread pitch gauges are really cheap on amazon.

https://www.amazon.com/Grip-Thread-P...s%2C152&sr=8-4

The outer diameter of the threads should measure slightly under the nominal diameter.

[Walleye Hunter]

If you have a tap and die kit, it might have gauges in it to measure threads, mine do.

[Royinmontco]

The nut method Daycrawler mentioned is pretty simple. Hell, you can measure both the OD and pitch with a ruler or tape measure, too.

[MrRuffGunz]

After a bit of research.. Mac 10/45 .45 cal barrels are threaded 7/8ths-9* that goes for the Masterpiece Arms Mac clone as well* The Mac 11/9 9mm barrels are threaded 3/4-10. I*m found the adapter finally at one place I have ordered from before usmachinegun.com. It Seems like a very hard thread adapter to get. Pricey too at $90!!! The adapter goes from 1/2-28(my 9mm Lage upper for the Mac) to the Bowers Vers45 silencer threaded 7/8ths-9* $90 it will be. I guess it*s not too bad it could be worse.

[Royinmontco]

Jeez, I could've turned that on my lathe in 20 minutes.

[bortle]

Jeez, I could've turned that on my lathe in 20 minutes.

Custom made adapters could be a nice side job @$270 hr.

[Royinmontco]

Custom made adapters could be a nice side job @$270 hr.

I'm thinking the product line would need to be far bigger to notice any significant income. But maybe as a side hustle? Hmmmmm......

[bortle]

I'm thinking the product line would need to be far bigger to notice any significant income. But maybe as a side hustle? Hmmmmm......

Probably not a real income stream, but a little side cash for the gun fund. Ask around some gun shops maybe.