5" or 9.25" barrel for suppressed 9mm upper

[packinheavy]

Now that Missouri is a suppressor friendly state I am going to be picking up a 9mm one with a 3 lug HK type attachment.

I want to build an upper for my SBR that will use a free float handguard to cover most of the can. It is also going to get used on a customized Walther P1 that the guys at C&S Metall Werkes in St. Charles are going to build for me(they have a P4 modified for a can there that I fell in love in love with but was already sold).

I am leaning towards the 5", but I have very little experience with suppressors and wanted to get the opinion of the more experienced. Ammo will be 147 grain subsonic stuff for the most part.

[LonghunterCO]

As to the can the SWR Trident gets high marks (that is the one that I am going with). It have removable end caps so that you could switch out the three-lug end cap for a threaded one for you handgun. If you plan on running a can the AR all the time then the 5" is the way to go. If you see yourself using the can on the .22 a lot and only occasionally then I would go with 9in on the AR.

[packinheavy]

The SWR Trident is actually the one they recommended to me.

I think the suppressor will spend more time on the AR than the pistol so the 5" is probably the better choice.

The Walther barrel is going to be modified with the three lug set up as well. The front sight will be moved to the slide like a P38K.

These toys sure get expensive. :)

[SHIVAN]

5" barrel and SWR Trident suppressor.

http://i235.photobucket.com/albums/ee192/SHIVAN308/Stuff/AR15-9mm.jpg

Yes, I realize I am missing my front sight -- it got cannibalized for a "primary" carbine. :p

[packinheavy]

5" barrel and SWR Trident suppressor.

http://i235.photobucket.com/albums/ee192/SHIVAN308/Stuff/AR15-9mm.jpg

Yes, I realize I am missing my front sight -- it got cannibalized for a "primary" carbine. :p

Thanks for the photo Shivan. That is exactly what I am looking to build.

[SHIVAN]

I originally had the 9.25" barrel on it, and thought that due to the longer barrel the suppressed sound signature would be muted compared to the shorter 5" barrel.

Harlan (thebomber) and I shot our guns side-by-side with no other shooting going on, and noticed that they sounded just about the same using the same batch of ammo and nearly identical setups, except his had the 5" barrel and mine had the 9.25" barrel. Was not scientific, but we each shot each other's gun, then shot our own, then asked witnesses...it was fairly unanimous that they sounded the same.

That very next day, I sold my 9.25" barrel and picked up the 5". Not only does it handle better, it's lighter and much more compact.

[chrismartin]

I like the 5" barrels:

http://web.mac.com/chrismartin/Gun_Stuff/AAC_3_Lug_EVO9_files/Media/IMG_0818/web.jpg

Keep in mind though, if you WANT the greater velocity, then the longer barrel might be needed. For fun though, the 5" is very hard to beat and it is very compact.

[LonghunterCO]

Whose mags and mag block are you all using. I got 7 new CP mags the week before the election so that is what I am going to have to use...

SBR paperwork has been inprocess for 2 weeks.:(

[SHIVAN]

I am using a Hahn dedicated mag block and COLT mags.

[wahoo95]

I'm a fan of the 5" barrel as well. Good luck with your build!

[shooter521]

I went with the 9.25" from TROS. If I want to shoot 9mm from a 5" barrel, I'll use my Glock 34. ;)

[Web Architect]

Those look like fantastic rigs, and a ton of fun to shoot. I shot a full auto MP5, suppressed last weekend. Other than the "fun factor," and perhaps some professional operator applications, is there a practical application for these?

[SHIVAN]

...is there a practical application for these?

Does there need to be? :D

[Web Architect]

Nope. Fun Factor suffices. Just curious...

[SHIVAN]

Pros: Quality 9mm ammo is cheaper then 556. Suppressed, quality 9mm subsonic is quieter then 556. Manual of arms is similar to the 556 carbine. Weight is less. Mag capacity is 2 more.

Cons: 9mm will not pierce most armor commonly available and used. 9mm has a poor trajectory compared to 556.

[packinheavy]

This is definitely going to be a toy. I really can't think of a real world use for it other than maybe "animal control" use.

I need to get the paperwork started. :)

ETA:

This just got more expensive. I just bought a Colt lighweight sporter 9mm lower to use. I was going to use my SBR lower and switch uppers back and forth but I decided to go the dedicated route instead.

Yes, I paid too much but I wanted it. :)