MP5-N Style 3 Lug Adapter Installation Guide

The purpose of this information is to provide a guide for what is required to install our MP5-N style 3 lug adapters.  We recommend having these adapters installed by a competent Hk gunsmith only.

We do the 3 lug installation.  The price for installation including the adapter and thread protector is $395, this amount includes touch up parkerizing. 

If you would like to purchase a 3 lug adapter and thread protector alone,  they are available for $59.00 at the following page IGF Products

Installation begins by shortening  the barrel  to exactly 1.400" beyond the front sight post and then threading either 1/2 x 28 or 1/2 x 32 depending on the desired muzzle thread.

The 3 lug adapter then needs to be fitted to the muzzle.  It is desirable to have the top lug at the 12 O'clock position.  We recommend removing material at the end of the adapter if necessary so that the adapter contacts the shoulder left at the front sight when the top lug is about in the 11:30 position.  This will allow the adapter to be torqued on slightly until the top lug is at the 12 O'clock.

The adapter should be attached after it has been fitted to the muzzle.  We recommend attaching by solder as shown in this photo.

Touch up finishing or refinishing can be done after the install.  The finish shown in this photo is manganese phosphate parkerizing.  The adapters are made from high carbon steel so they parkerize nicely to match the look of an original Hk MP5-N 3 lug style barrel.

We include the appropriate threaded thread protector with the adapters.  This protector is knurled and turned to allow MP5 3 lug accessories, such as 3 lug flash hiders, to fit over it.   We do make the thread protectors slightly long so that they also protect the muzzle and crown of the barrel.  Occasionally the thread protector may need to be shortened slightly to allow some Hk flash hiders to engage the lugs of the adapter.  This can be done easily with a file or sandpaper, no special tools are required for this.