searched to no avail... wrong barrel thread for 1911, 575x40

[Jonathansevert]

Well, ordered my 1911 barrel. Thought I chose 578x28, received 575x40. Contacted storm lake and thry said I would have to wait a couple months.

I chose the thread to buy a suppressor, but figure the lathe I own should make something fun!

My question is this: why is 578x28 so commonly available for suppressors and nothing in 575x40? First I thought threads are too fine, maybe too many twists. Why is it?

[Capt. Link.]

Well, ordered my 1911 barrel. Thought I chose 578x28, received 575x40. Contacted storm lake and thry said I would have to wait a couple months.

I chose the thread to buy a suppressor, but figure the lathe I own should make something fun!

My question is this: why is 578x28 so commonly available for suppressors and nothing in 575x40? First I thought threads are too fine, maybe too many twists. Why is it?

You are correct on both counts.There is little contact area per thread at 40 tpi vs 28 and a bunch of turns would be required.If you are making your own you can use 40 tpi just tighten your tolerances for thread fit and use a hardened steel to allow for wear.If you have the equipment and know how to use it you can learn to make a very fine suppressor right here!

[Jonathansevert]

Thank you! So... Using the three wire method, I can get the exact I.D. for threading and use the barrel as myGO/NO-GO?

[LavaRed]

You could put a compensator on it that also acted as a QD attachment point for the suppressor, using a coarser thread .

[Jonathansevert]

Where is that!!


Shut up and take my money!

[Jonathansevert]

For inner diameter, is the formula .575- 1/40? Or am I nuts? I can't remember!!