Picked up a Ultra Compact kit from the LWRC booth at the NRA Annual Meeting today.  

So what buffer are folks using with a 5 to 5.5 inch 9mm barrel?

Thanks,

Mark

UPDATE - - - See my post below where I have success with a COLT 9mm buffer!

Good info here:  http://www.ar15.com/forums/t_3_15/666528_9mm_with_LWRC_UCIW_Ultra_Compact_stock_.html

Seems like you can cut down the "bumper" from a carbine buffer and it will be the same height as the Heavy Buffer(Slash) U9 9mm buffer.  Weight will be different but height will be the same.

Slash's makes a specific 9mm buffer for the Ultra Compact Stock   I've got one and it works great.

You're right a lot of good info in that thread.

Thanks!

Mark

This Worked for Me.

Colt 9mm Buffer with cut-down bumper along with a Wolff Extra Power Carbine Buffer Spring.

Here is a pic that beanfield33 posted in the above linked thread.  Using my Redneck Engineering Calibration Device (MK-1 eyeball) I trimmed the bumper at the redline in the pic.



The UCIW was installed on a Black Creek Precision EF9 - Reduced Mag Well Dedicated 9mm lower.  BCP uses a bolt catch lifter design that allows the use of a standard lower parts kit bolt catch that does away with the dedicated extended arm 9mm bolt catch.  The upper is an Aero Precision no forward assist with a 16 inch barrel installed.  I used both a CMMG & MAS bolt to test compatibility.

I ran a little over 100 rounds of Federal, Perfecta, and WWB 115g FMJ through the gun loading ASC & Metalform mags with singles, doubles, and full 32 rounds.  I fired singles, controlled pairs and rapid 4-6 round shots.

Not a single issue.  

The BHO worked every time and I had no blast in my face.  I felt no bolt bounce.  After firing an inspection of the buffer bumper showed no signs of contact or any other unusual wear on the firearm.

For those looking for a lower cost set-up using the UCIW, this Colt buffer/Wolff HP combination might work.  My only specific stipulation would be that I cannot measure what the affect of the BCP's bolt catch lifter had in the 100% BHO function.

Mark

What's your overall buffer length and weight now? I'm thinking of just cutting the bumper on a standard H3 buffer and trying that.

Carbine buffers are 3.25" so my guess is he cut down to approximately 3/3.05" to match UC buffer length. Weight is prob 5.5 oz per Colt 9mm buffer specs. Nice work.

Does anybody know what the heaviest carbine buffer is? I have the U9 at 8.5 oz but I'd like even heavier if possible for suppressed used. The "Q" or extended 9mm buffers are too long with UCIW stock.

The Heavybuffers.com one is 8.5oz and is only $150 with the spring   if you buy the xtra heavy carbine buffer it's only $140 with the spring and you can just cut the plastic tip yourself.

I was thinking a standard 9mm buffer would probably work with a little trimming. Nice work.

On my scale the Colt buffer came in at 5.4oz After cutting the bumper down.  Its about 3.10 in length.

The bolt just clears the BHO with the XP spring.  A regular carbine spring was test fitted and it did give more clearance for the BHO to engage the bolt as did the UCIW flat wire spring.

I started with the XP spring and had planned to swap out with the other springs, but the gun ran so well with XP spring that I didn't feel the need to do that.  

I used the Colt buffer because I had a spare one.  Otherwise a H3 should work just as well since its 5.4oz.

Again, I want to point out that the BCP lower uses a bolt catch lifter.  I don't know if this same buffer/spring combination would work with a different dedicated 9mm lower or one using an insert.  

Mark