WTK: AAC 51T ACME thread pitch once and for all!

Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.

Moderators: mpallett, bakerjw

Post Reply
1968firebirdguy
New Member
Posts: 3
Joined: Wed Aug 27, 2014 10:51 pm

WTK: AAC 51T ACME thread pitch once and for all!

Post by 1968firebirdguy »

Hey guys, hopefully one of you can help me out.

I have searched high and low but I haven't been able to find a solid be all end all answer.

what size is the ACME thread pitch on the 51T flash hider?? is it 8 tpi , 7 tpi , 7.5tpi????

any one!! my google fu seems to be lacking at the moment :-)
User avatar
john.t.little1
Silent But Deadly
Posts: 243
Joined: Thu Nov 24, 2011 12:13 pm
Location: florida/iraq

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by john.t.little1 »

i seem to remember bender saying its close to 9.5 if i remember correctly…
"A man is known by the silence he keeps. - Oliver Herford"
"Gunpowder, treason and plot. I see no reason why gunpowder, treason
Should ever be forgot..."
1968firebirdguy
New Member
Posts: 3
Joined: Wed Aug 27, 2014 10:51 pm

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by 1968firebirdguy »

135 views and still no solid answer?

come on guys some one has to know for sure :-)

if I had the means of measuring the threads I would figure it out myself but I don't have the the right equipment to do it correctly.
User avatar
john.t.little1
Silent But Deadly
Posts: 243
Joined: Thu Nov 24, 2011 12:13 pm
Location: florida/iraq

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by john.t.little1 »

Ask this guy

sizulku wrote: Hi Gunny,

Which one is perform better, using the same spacing length or different spacing length?

I build my 556 nato can based on AAC M4-2000 above. Its 2" diameter and 10" long. Nine 60-degree cones baffle. Bore is 0.252" and all spacer is 0.5".
I shot side-by-side at the range with AAC M4-2000 and unable to tell difference the sound of this can compare to AAC M4-2000 except the size and weight. I'm not happy with this result. the good thing of this can is I don't get POI shift.

Any suggestion?

Image
Image
"A man is known by the silence he keeps. - Oliver Herford"
"Gunpowder, treason and plot. I see no reason why gunpowder, treason
Should ever be forgot..."
1968firebirdguy
New Member
Posts: 3
Joined: Wed Aug 27, 2014 10:51 pm

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by 1968firebirdguy »

John


Thanks for the reply , I did infact try asking him and I never got a response. He said he was going to check his notes and he never got back me in the post.

I may try to find one of those little fold out thread combs in ACME and take it to the flash hider I have , I have heard many different sizes from people, I know the YHM phantom threads are 8tpi and it looks really close to the AAC so I was figuring it's gotta be close to that.

Thank you again for the help
User avatar
john.t.little1
Silent But Deadly
Posts: 243
Joined: Thu Nov 24, 2011 12:13 pm
Location: florida/iraq

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by john.t.little1 »

You're welcome. I do believe bender knows and I seem to remember him saying it's 9.5ish
"A man is known by the silence he keeps. - Oliver Herford"
"Gunpowder, treason and plot. I see no reason why gunpowder, treason
Should ever be forgot..."
sizulku
Silent Operator
Posts: 87
Joined: Tue Dec 11, 2012 10:35 am
Location: Asia

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by sizulku »

Hi Gents.

Sorry for delays. I use metric thread number 4 as shown on the picture below.

Image

this is the machine
Image

metric thread pitch list
Image

my setup
Image

making aac nut
Image

result
Image

hope this help.
User avatar
john.t.little1
Silent But Deadly
Posts: 243
Joined: Thu Nov 24, 2011 12:13 pm
Location: florida/iraq

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by john.t.little1 »

:shock: Not worthy… thank you Sir you have done a great service for all..
"A man is known by the silence he keeps. - Oliver Herford"
"Gunpowder, treason and plot. I see no reason why gunpowder, treason
Should ever be forgot..."
User avatar
ken226
Silent Operator
Posts: 79
Joined: Sat Nov 16, 2013 10:51 pm
Location: NM

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by ken226 »

so, a 4mm pitch makes kit 6.35 tpi. I thought 9.5 would be a little odd, most manual lathes wouldn't be able to cut a 9.5 pitch i wouldnt think. I'm sure it wouldn't be a problem for a CNC.

A 4mm pitch should be doable on most machines.
02/07 FFL-SOT
Zero99z
Silent Operator
Posts: 77
Joined: Wed Nov 13, 2019 9:50 am
Location: Minnesota

Re: WTK: AAC 51T ACME thread pitch once and for all!

Post by Zero99z »

Sorry to hijack the thread, but if someone has the acme thread pattern for the AAC Cyclops it would be much appreciated.
Post Reply