Experimental suppressor thread on Vudoo reduces trash in bore.

[Hellbender]

Got my Vudoo a few weeks ago, ordered it without a threaded muzzle because I wanted a special thread design they couldn't make work in their production run.

Sent it to Longrifles, Inc, as they had done work for me in the past, and they said it would be no problem.

My design was a simple extension of the un-threaded portion of the Silencerco thread spec by about .100". This moves the end of the muzzle into the blast chamber about .050", thus making a lip to catch the crud that falls into the blast chamber, and keeps it there instead of it all sliding down the bore if you turn your muzzle up.

3 muzzle threads in this pic, left to right....My design....Standard SiCo spec....Regular Everyone Else's (REE) thread.

The standard SiCo and Regular Everyone Else's (REE) thread performed almost exactly the same so, for simplicity, I will only compare the REE to My thread in the rest of the discussion.

I used two representative types of supressors for the test, a SiCo Sparrow (monocore) and a SiCo Spectre II (8 cone style baffles with a blast chamber)...

Here's some pics showing the blast chambers with both thread types...

REE in Spectre II

MY Thread in same....

REE in Sparrow...

My Thread in Sparrow...

I then got the finest grained powder I could find in my reloading room, some Win. 296, and measured out 5 grains (by weight).
I attached each suppressor to the muzzle and carefully sprinkled the powder evenly throughout the baffles with the barrel held over at a sharp angle so none would slide down the bore until I started the test.
I then put the chamber end in a bowl to catch all the powder that would drop down the bore.
I then moved the bbl back and forth 10 times evenly side to side, then stopped with the muzzle pointed straight up and tapped the end twice for each test.
I then weighed how much powder had dropped into the bowl from the bore.

I repeated this test 4 times for each combo of suppressor and thread type.

Here are some pics of what's left in the suppressor after the test.

REE in Sparrow.....

My Thread in Sparrow...

REE in Spectre II...

My Thread in Spectre II...

Continued in next post.

 

[Hellbender]

My results.

Sparrow...

Spectre II....

As you can see the multiple cone baffle design dumps a LOT more stuff down the bore than the monocore. Almost all of the junk drops down the little funnels to the blast chamber.

This is partly why some people have trouble with debris and some don't (in addition to different ammo dirtiness, of course).

I'm glad I did the modified thread, it will keep a lot of junk out of my action.

 

[missed]

Good info,

I have been thinking about a reverse cone with a 0.015-0.20 flat spot.

 

[Hellbender]

Missed, I was gonna do a reversed cone, but I didn't want to affect the accuracy that everyone says the 11 deg taper (supposedly) imparts.

I don't know how big, or small, the 11 deg. part has to be.

So I went the safe route.

 

[bmicek]

Never thought about something like this. Awesome idea and data.

 

[Rebels010]

Good info. Thanks for sharing.

 

[billmeek]

Interesting idea! I know very little about suppressors. Would moving the muzzle deeper into the silencer chamber have any effect on sound levels or accuracy?

Looking at the Silencer Co spec vs the REE, it appears that the Silencer Co thread should be performing the same function as your thread but just to a lessor degree. However, the numbers you provided show it's performing worse.

 

[45cal4life]

Very interesting, I never gave it any thought

 

[Hellbender]

Interesting idea! I know very little about suppressors. Would moving the muzzle deeper into the silencer chamber have any effect on sound levels or accuracy?

Looking at the Silencer Co spec vs the REE, it appears that the Silencer Co thread should be performing the same function as your thread but just to a lessor degree. However, the numbers you provided show it's performing worse.

Can't imagine how it would affect either, but I was wrong once when I was younger. If anything I would think it would reduce turbulence directly at the muzzle by letting the gases travel more like an open muzzle instead of hitting the lip of the threaded area.

Actually the SiCo was a little better than the REE (smaller amounts are better) but they were close enough that 10 more tests may have made them equal.

Any thread that is below the level of the blast chamber floor will, IMO, be about the same as the REE, as they will all allow the debris to slide down the bore and not keep it in the blast chamber like my design.