Multiple threads for QA/QD mount?

[L1A1Rocker]

It looks like all the factory screw on QA/QD muzzle breaks only use one thread. I was considering an 8 or 9 TPI using multiple threads. Has anyone ever done this? If so any information?

[Bendersquint]

It looks like all the factory screw on QA/QD muzzle breaks only use one thread. I was considering an 8 or 9 TPI using multiple threads. Has anyone ever done this? If so any information?

My SCAR H SD can from AAC is a multiple start thread mount.

[L1A1Rocker]

It looks like all the factory screw on QA/QD muzzle breaks only use one thread. I was considering an 8 or 9 TPI using multiple threads. Has anyone ever done this? If so any information?

My SCAR H SD can from AAC is a multiple start thread mount.

Interesting. This Blackout only has a single thread.


I was thinking about turning two threads at 8 tpi with a flat 15* shoulder. What's you opinion on that? Also, how much engagement would you think. . . 1/2 inch maybe?

[Grounded]

It looks like all the factory screw on QA/QD muzzle breaks only use one thread. I was considering an 8 or 9 TPI using multiple threads. Has anyone ever done this? If so any information?

My SCAR H SD can from AAC is a multiple start thread mount.

Interesting. This Blackout only has a single thread.


I was thinking about turning two threads at 8 tpi with a flat 15* shoulder. What's you opinion on that? Also, how much engagement would you think. . . 1/2 inch maybe?

That blackout is an ACME thread which is stronger. I would do a higher tpi over a shorter length with a multi point start.

[L1A1Rocker]

It looks like all the factory screw on QA/QD muzzle breaks only use one thread. I was considering an 8 or 9 TPI using multiple threads. Has anyone ever done this? If so any information?

My SCAR H SD can from AAC is a multiple start thread mount.

Found a picture of one of those:


That looks to be four threads cut there. Is that correct? Is that 4 TPI???? I'm just eyeballing a picture here but that looks like a FAST twist.

[Homer]

G'Day Fella's,

L1A1 Rocker, the flash eliminator/QA-QD mount has what appears to be a 2 or maybe a 3 Start Tread!
This is basically 2 or 3 separate threads, on one part of a piece of material!!!

This is nothing new, as I learnt about them when I did my apprenticeship 30+ years ago!
The down side of these is they can move easily, which in this instance has been addressed with the ratchet locking system, on the LHS of this!!!

Hope that helps

Doh!
Homer

[L1A1Rocker]

G'Day Fella's,

L1A1 Rocker, the flash eliminator/QA-QD mount has what appears to be a 2 or maybe a 3 Start Tread!
This is basically 2 or 3 separate threads, on one part of a piece of material!!!

This is nothing new, as I learnt about them when I did my apprenticeship 30+ years ago!
The down side of these is they can move easily, which in this instance has been addressed with the ratchet locking system, on the LHS of this!!!

Hope that helps

Doh!
Homer

Correct. The premise of the O.P. is that most use a single fast thread. I'm looking at doing 8 or 9 TPI and possibly cutting two threads and using a flat 15* shoulder - not a ratchet setup.

There are a few companies that do the non-ratched, flat 12 or 15* shoulder but only use a single thread. I'm tossing out the idea of doing this, but with multiple threads, for input.

[daleper]

Would the multi thread approach create a change in POI shift as the can wouldn't nesecarily index the same evety time it is installed?

[L1A1Rocker]

Would the multi thread approach create a change in POI shift as the can wouldn't nesecarily index the same evety time it is installed?

In a non-symmetrical baffle system I could see how you might have a wandering POI shift. However, in a symmetrical baffle stack there shouldn't be a problem. Of course you could also mark "top" so that the silencer is mounted in the same orientation every time.

[jreinke]

Here's info I copied out of a machine tool book on how to cut them.

PITCH EXAMPLE CLAMP POINT
Double lead pitches 10-14-18-22-26… Must be an even pitch divisible by 2 equaling an odd number, i.e.
10/2=5 or 14/2=7, ect. 1st lead close on 1 or 3, 2nd lead 2 or 4.

PM me your email address and I'll send you an article from the 1940's on how to cut multiple lead threads. Very detailed to good charts.

[57fairlane]

Would the multi thread approach create a change in POI shift as the can wouldn't nesecarily index the same evety time it is installed?

that was actually the point . . . kinda.

The idea was to be able to re-index the can to find the position the groups wandered off the least amount from unsuppressed.

[L1A1Rocker]

It looks like all the factory screw on QA/QD muzzle breaks only use one thread. I was considering an 8 or 9 TPI using multiple threads. Has anyone ever done this? If so any information?

My SCAR H SD can from AAC is a multiple start thread mount.

Found a picture of one of those:


That looks to be four threads cut there. Is that correct? Is that 4 TPI???? I'm just eyeballing a picture here but that looks like a FAST twist.

Also, do you think that fast twist would work with a smooth 15* mating shoulder? The Thunder Beast uses something like a 15* mating shoulder without any ratchet system. The difference with that though is it uses a single thread with what looks to be around 20TPI.

I'm curious on your thoughts on this Bender.

Thanks

[Bendersquint]

It looks like all the factory screw on QA/QD muzzle breaks only use one thread. I was considering an 8 or 9 TPI using multiple threads. Has anyone ever done this? If so any information?

My SCAR H SD can from AAC is a multiple start thread mount.

Found a picture of one of those:


That looks to be four threads cut there. Is that correct? Is that 4 TPI???? I'm just eyeballing a picture here but that looks like a FAST twist.

Also, do you think that fast twist would work with a smooth 15* mating shoulder? The Thunder Beast uses something like a 15* mating shoulder without any ratchet system. The difference with that though is it uses a single thread with what looks to be around 20TPI.

I'm curious on your thoughts on this Bender.

Thanks

I personally wouldn't use an ACME thread like that without a means to secure it once installed. It wobbles pretty good while threading it on.

I will have to pull the SCAR from the safe and measure the threads on it.

[L1A1Rocker]

I personally wouldn't use an ACME thread like that without a means to secure it once installed. It wobbles pretty good while threading it on.

I will have to pull the SCAR from the safe and measure the threads on it.

Wow, that would be great.

Here's a pic of the Thunderbeast mount that I was talking of.



What would you think of national form threads?