Alton C. is a guest writer for TFB and has contributed a number of articles in the past.
The HK G3 is still soldiering in active service on more than fifty
years after its introduction, but its ergonomics requires updating in the
modern age. The long length-of- pull is inconvenient for body armor use
and the comb only affords a chin weld with optics. The Spuhr
collapsible stock assembly addresses all these concerns and will equip
the AK4B (locally produced G3) of the Swedish Armed Forces.
Spuhr stock assembly with R-401 optical front rail and TA44 ACOG
The original metal back plate and buffer is mated to the Spuhr buffer
tube with either a long spacer (for standard G3 buffer) or a washer-thin
spacer (for long pneumatic buffer found on HK21/23 and AK4B). The
stock is then attached to the buffer tube similar to an AR-15. Lastly, the
cheek riser is secured at the front with a screw. The Spuhr product fitted
perfectly on the author’s PTR91 GIR, an American manufactured G3
The castle nut endplate provides one HK hook attachment point on
each side and duplicates the location of the Swedish Armed Forces
issued vapenfäste kolv strap system.
Stock adjustment lever denoted.
The six position stock can be adjusted from 40cm to 32cm (trigger to
buttpad). A spring loaded lever at the lower front of the stock is pulled
down for adjusting length with no lock necessary for a tight fit. This
adjustment can be performed with one hand after some practice.
The cheek riser is stationary and independent of stock position, as the
stock slides along a key on the underside of the cheek riser. The standard
riser worked well with the Trijicon TA44 ACOG on a high mount, but
8mm and 12mm ones are also available to accommodate larger objective
scopes and their taller mounts. While the iron sights are no longer
useable, the improved check weld with optics is more than a fair
Spuhr noticeably reduced felt recoil by improving the fit to user, and
by placing the stock in-line with the barrel. The square-on stance
afforded by the shorter stock allowed better recoil management and
protection when using armor. The serrations of the buttplate provided
positive grip with the plate carrier and slick clothing alike. A rubber pad,
to be released in the future will be sure to further improve handling.
The original stock positioned the shoulder below the recoil vector
which induced additional muzzle rise. The in-line positioning of the
Spuhr stock assembly was well proven in designs like the FG-42 to
mitigate such effects. This greatly tamed the recoil of the violent G3
roller delayed action.
Upgraded G3 can be used by the petite.
Spuhr collapsible stock assembly modernizes the G3 with improved
ergonomics and reduced recoil. The adjustable stock improved fit to
individuals and shooting positions, while the cheek riser improved optics
use. The in-line position of the stock with the barrel greatly tamed the
recoil to reduce fatigue and split times. These improvements are well
worth the consideration of any G3 user.