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6/12/2026 1:45:19 PM EDT
[#1]
From HTA's website:

Attached File

Know Guns, Know Peace, Know Safety...No Guns, No Peace, No Safety
6/12/2026 2:19:39 PM EDT
[#2]
I only use 124 NATO in my SD conversion.  Some people say 115 works for them, I honestly don't see how.  I have pistols that 115 won't reliably cycle, much less an MP5SD.
6/13/2026 12:58:34 AM EDT
[#3]
Pretty much what i was thinking.
That also saves me a little money with a future barrel swap.

But it would still be neat to have a true sd, from a reference/cool factor standpoint.
6/13/2026 7:17:30 AM EDT
[#4]
Quote History
Originally Posted By Gibbles:
Guys with the true sd conversion, any ammo concerns?

My standard bulk ammo purchase is usually cci independence or blazer brass 115gr.

Weighing what i want to do with mine...

This thought came up as I troubleshoot an ejection issue with a frt in a full sized ap5.

It highlighted a slow cycling issue i see with my binary lower.
I can easily out run it.

I'm thinking the stuff can't fully cycle with the added weight of the trip.



I'll find out here shortly if I'm totally wrong with my thought process.

I have the RCM 115 degree "SD" locking piece installed and some different ammo for its next attempt.

It's probably something else like the MKE ejector that i had to hack up for the install, so who knows.  
View Quote



I shot up the 300rnds of Win 124gr NATO ammo I brought to the range in the last trip and a few friends wanted to shoot it a little more. We tried 115gr Blazer Brass and it choked at least once a mag. It also seemed a bit louder than the 124 gr stuff.
7/2/2026 9:49:17 AM EDT
[#5]
Well i took my AP5SD into a shop last night to do some can test fitting.

I also saw the sizing that others have gotten away with, hoping to use those for a reference.

They didn't have any of the fatter cans in stock, but i have a need right now.

And i need a 9mm can for my property/range.

I shoot a ton of 9 when i head up there, and i do have a neighbor that gets to listen to it if we are up there at the same time.

So i do some fitting.
They did have a "sub gun" can that was on the fatter side, and fatter than the fo can on the sd.

That thing was like 1.4 something iirc.

It showed me a potential issue with my SD.

The top of the supressor cage is tighter than the rest.
I haven't spent time looking at things to understand what's happening.

But I'm starting to wonder if the cocking tube is slanted downwards, and the cage right along with it.


Anyone else notice something like this?
7/2/2026 11:41:30 AM EDT
[#6]
Quote History
Originally Posted By Gibbles:
Well i took my AP5SD into a shop last night to do some can test fitting.

I also saw the sizing that others have gotten away with, hoping to use those for a reference.

They didn't have any of the fatter cans in stock, but i have a need right now.

And i need a 9mm can for my property/range.

I shoot a ton of 9 when i head up there, and i do have a neighbor that gets to listen to it if we are up there at the same time.

So i do some fitting.
They did have a "sub gun" can that was on the fatter side, and fatter than the fo can on the sd.

That thing was like 1.4 something iirc.

It showed me a potential issue with my SD.

The top of the supressor cage is tighter than the rest.
I haven't spent time looking at things to understand what's happening.

But I'm starting to wonder if the cocking tube is slanted downwards, and the cage right along with it.


Anyone else notice something like this?
View Quote


The cages on those aren't welded enough, so that's possible.
7/2/2026 12:20:24 PM EDT
[#7]
Quote History
Originally Posted By Goosemaster:


The cages on those aren't welded enough, so that's possible.
View Quote View All Quotes
View All Quotes
Quote History
Originally Posted By Goosemaster:
Originally Posted By Gibbles:
Well i took my AP5SD into a shop last night to do some can test fitting.

I also saw the sizing that others have gotten away with, hoping to use those for a reference.

They didn't have any of the fatter cans in stock, but i have a need right now.

And i need a 9mm can for my property/range.

I shoot a ton of 9 when i head up there, and i do have a neighbor that gets to listen to it if we are up there at the same time.

So i do some fitting.
They did have a "sub gun" can that was on the fatter side, and fatter than the fo can on the sd.

That thing was like 1.4 something iirc.

It showed me a potential issue with my SD.

The top of the supressor cage is tighter than the rest.
I haven't spent time looking at things to understand what's happening.

But I'm starting to wonder if the cocking tube is slanted downwards, and the cage right along with it.


Anyone else notice something like this?


The cages on those aren't welded enough, so that's possible.

They also ship with a standard MP5 cocking tube support.  There’s a side of it that hangs into the cage space and can compatibility issues with some cans.

I swapped my cocking tube support for an RCM SD-style one that mills away the edge that would rotate into the space.  Pretty sure my SD conversation wouldn’t have worked without it.

https://rimcountrymfg.com/product/rcm-sd-cocking-tube-support/
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7/2/2026 2:55:16 PM EDT
[#8]
Quote History
Originally Posted By Findsman:

They also ship with a standard MP5 cocking tube support.  There’s a side of it that hangs into the cage space and can compatibility issues with some cans.

I swapped my cocking tube support for an RCM SD-style one that mills away the edge that would rotate into the space.  Pretty sure my SD conversation wouldn’t have worked without it.

https://rimcountrymfg.com/product/rcm-sd-cocking-tube-support/
View Quote View All Quotes
View All Quotes
Quote History
Originally Posted By Findsman:
Originally Posted By Goosemaster:
Originally Posted By Gibbles:
Well i took my AP5SD into a shop last night to do some can test fitting.

I also saw the sizing that others have gotten away with, hoping to use those for a reference.

They didn't have any of the fatter cans in stock, but i have a need right now.

And i need a 9mm can for my property/range.

I shoot a ton of 9 when i head up there, and i do have a neighbor that gets to listen to it if we are up there at the same time.

So i do some fitting.
They did have a "sub gun" can that was on the fatter side, and fatter than the fo can on the sd.

That thing was like 1.4 something iirc.

It showed me a potential issue with my SD.

The top of the supressor cage is tighter than the rest.
I haven't spent time looking at things to understand what's happening.

But I'm starting to wonder if the cocking tube is slanted downwards, and the cage right along with it.


Anyone else notice something like this?


The cages on those aren't welded enough, so that's possible.

They also ship with a standard MP5 cocking tube support.  There’s a side of it that hangs into the cage space and can compatibility issues with some cans.

I swapped my cocking tube support for an RCM SD-style one that mills away the edge that would rotate into the space.  Pretty sure my SD conversation wouldn’t have worked without it.

https://rimcountrymfg.com/product/rcm-sd-cocking-tube-support/


I forgot about that. My SP5 to MP5SD conversion has the enhanced cocking tub support too. Without it, B&T cans won't fit.
7/3/2026 11:43:22 AM EDT
[#9]
Sounds like i need to break out some tape and calipers.

I think the wolfman is a good look, so I'll try and get close to that dia.

For now i have an Obsidian 9 in nfa jail.

Trying out the silcencer co. kiosk... lol
7/3/2026 1:34:17 PM EDT
[#10]
I converted my AP5SD with an RCM barrel and BRT adapter for rex mg7k. Got horrendous port pop. Swapped in a 100 degree rcm locking piece and now I like the SD. Runs 115gr great.
9/16/2026 11:05:55 PM EDT
[#11]
Coming back to this.
I just brought home a wolfman and converted it from kemo to direct thread.

It's perfect, I could probably go a tiny bit fatter, but the top of the can is a little tighter than the rest.

Seems like i made the correct decision.

Looks freaking awesome on it too.
9/20/2026 8:55:32 PM EDT
[#12]
Shot this thing a bit more yesterday. Was getting some crud on my support hand so I removed the can and sure as heck…o-ring finally died. Replaced it and good to go. This has quickly become one of my favorite guns.

Attached File
Attached File
9/20/2026 9:22:31 PM EDT
[#13]
From the MO Hometown Shoot:

AP5 SD EXIGENT DEFENSE RICO309 w/ subs


FRT Century AP5 SD RICO309 aka The Crowd Pleaser


I got to try a K model today. I need it
Know Guns, Know Peace, Know Safety...No Guns, No Peace, No Safety

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