M12 155mm GMC Academy 1/35
M12 155mm GMC Profile

The M12 155mm gun motor carriage is a must for any US WWII armor collection.  Especially important in the breakout of Normandy, these self propelled guns were frequently the only heavy artillery within days march of the front.  The M12 could move 6 miles to a new firing position in 35 minutes compared to towed artillery which took 3 hours.  When the US forces came up against the heavy fortifications of the Siegfried Line in the Fall of 1944, the M12 proved an effective means for their destruction.  Using direct fire at 1000 to 2000 yards, the 155mm projectiles proved deadly to the pillboxes.

To date, the only kit of the M12 in 1/35th scale is the Academy kit.  The kit was issued in 2000.  Steve Zaloga wrote an excellent article, in the same year, on building and improving the kit.  If you are going to build this model, I highly recommend referencing Steve’s article, here.

Out of the box, the kit builds up nicely.  That is, the parts fit together pretty well.  However, the completed model has a number of dimensional issues.  The following article is under construction as is the model.  I am currently building and rebuilding the kit, attempting to work out various approaches that would correct the different issues with varying degrees of effort.  Along the way I will be taking advantage of parts provided by newer, more accurate Sherman kits.  Some modelers might find these corrections insignificant.  However, in my collection, the model is displayed alongside several Shermans where the dimensional discrepancies appear more obvious.

As built from the box, the model stands between 4½ to 6 scale inches too high.  Scale ground clearance should be 17”.  In the overall, the model is a little shy of 6 scale inches too narrow.  Because the M12 was based around the M3, the specs indicate the M12 width without sand shields to be 105.3”, slightly wider than a standard M4 Sherman which measures out at 103”.  I am not quite sure how Academy did it, but the lower hull is the right width, however, the upper hull is narrower than an M4 Sherman.

Academy M12 155 GMC

Academy always seems to have problems with their rendition of the VVSS Sherman suspension system.  In the case of the M12, the suspension arms are molded in a position that simulates a vehicle of very little weight.  Note the angle of the suspension arms #2 in Fig.2.  The wheels are molded with a chunky rim and tire profile, #3.  The skid shown is of the latest design and probably the least common to be found on M12’s, but it is consistent with the suspension arms included in the kit.  The kit also includes the earliest skid design (also not very common to the M12), but using these would be out of place with the cut-out suspension arms.

M12 155 GMC Suspension Bogie
Academy M12 155 GMC Suspension Bogie

Figure 3 illustrates the outline of the kit suspension unit against the actual unit.  The kit arms are overly angled.  You can see how the kit suspension will noticeably raise the vehicle height.  The increased angle of the suspension arms also increases the space between the wheels of the adjacent bogies.   Finally, the return roller bracket arm, as represented in the kit, is too short.

Two possible solutions to the vehicle height would be to either use a completely new suspension unit such as, Fig. 4; or simply substitute the suspension arms and wheels, Fig 5.  In both cases, I am using Dragon components.  The wheels and solid suspension arms come from the early units with the center mounted return roller.  These units are found in Dragon’s early M4A1 kits.  I prefer to use the entire Dragon unit as the suspension arms seem to sit a bit too low using the Academy suspension body (yellow arrows).  Also, the return roller bracket arm is the correct length.  The Dragon units center up with the indents on the bottom of the Academy hull.  Tasca makes a suitable suspension bogie as well, but mounting them on the Academy hull will be much more involved.

M12 155 GMC Suspension Bogie Compared
Dragon M4 suspension unit
Academy M12 improved suspension

Here are the completed Dragon suspension units compared with the stock Academy units.  I used some spare skids from Tasca.  Note how the vehicle ground clearance has now been restored to the scale 17”.  While not readily apparent to the novice eye, when compared side by side, the difference is quite striking.

Academy M12 155 GMC Suspension improvements