The mysterious front flat on the Soumi blanks
 

Q: My Soumi tube doesn't have a flat on the front bottom edge, why not - is it defective?

 

A: We (HellBox Armory) never have done a flat on the Soumi tubes - At one point or another Prexis did prior to our acquisition to the manufacturing rights, however due to the minor variances in kits it was decided that the cut depth and width was near impossible to make and have it be exact for "all" kits.

 

The pictures below will help illustrate how to take the dimensions from your front filler, trim the filler bracket to the those sizes and then transfer that to the tube itself..

 

The only precautions are outlined in the instruction sheet that came with the tube and is regarding the shifting of the insert (IE welding or pinning it in place). The warning reads as follows:

Important Note:

Depending on what means and methods you are using to make the ejection port opening and magwell cuts it may be possible to dislodge the insert that is pressed into the nose of the tube body itself. It is highly recommended that a .125 hole be drilled no deeper then .250 located approximately .220 behind the center of the magazine opening (on what will become the bottom of the finished tube). A matching .125 steel pin can be driven into the hole and a light weld be applied over the hole to hold the pin in place.
If more confidence is desired or if using a milling machine (due to the high tork loads) it is further recommended machining the ‘stub” cut first. Once the stub cut out has been finished a light welding can be made over the insert to tube body seam located .200 from the outside edge. (see red shading in photo below).

 

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In the photo below the front filler is seen from above as is the "stub" that is included in the HBA Soumi kit (the stub in is the lower half of the picture and the filler in the upper half)

This is the current HBA tube as shipped

The following 3 pictures demonstrate how the flat should look once cut, also the red outlining is the recommended weld placement mentioned in the note above.