Saturday, June 20, 2009

Tantal Build Log

I needed a clearing of the palette if you will after the disaster that was the Tabuk barrel (more on that later), so I decided to try and put together a kit I had lying around – a Polish Tantal. The Tantal, or karabinek wz. 1988, is a select fire version of the AK-74. Unlike the AK-74, the fire mode is determined by a selector on the left side of the weapon. This selector has three settings: fully automatic fire (the “C”-marked position), semi-automatic fire (“P”) and 3-round burst fire mode (“S”). Like other AK variants, it has the standard bar safety on the right hand side of the receiver. Because of the unique fire control group, the trigger assembly and receiver are a bit different than normal AK-74 variants. I used the NoDak Spud Model NDS-2T receiver for my Tantal build because it is actually set up for the left hand selector. Unlike the Tabuk build, this is as close to a “shake and bake” job as I’ve ever done on an AK build. Everything just seemed to fall into place.

I started with a full Tantal kit. This particular one had the “Oval 11” code and a 1990 manufacturing date. All of the parts are stamped matching, though the finish was quite worn in spots. The chrome lined barrel, however, seems to be in excellent shape. The receiver parts had been removed, but the remains of the rivets were still in all of the trunnions. I started with the front trunnion by removing the barrel, then drilling and tapping out the rivets. The rear trunnion is of the two long rivet type, but both drilled out fairly easily. Removing the trigger guard rivets was a little bit of a pain, but they came out cleanly leaving me with a very serviceable trigger guard, magazine catch, and safety stop.

The NoDak Tantal receiver is pre drilled for all of the rivets on the trunnions and trigger guard. Pre-drilled receivers save me a lot of time, and I prefer them whenever possible. The only drawback is that sometimes the magazine fit is tight and requires grinding afterward. When I test fit the front trunnion into the receiver, I was pleased to see that it lined up perfectly. As all six of the front trunnion rivets were countersunk for swell neck rivets, I indented the receiver with my AK-builder tools before placing those rivets. After riveting the front trunnion I went ahead and reinstalled the barrel and broke for the evening.

The next day I picked up where I left off and installed the rear trunnion and folding stock. I’d drilled these out as a group and simply left the stock attached to the trunnion. Both long rivets were countersunk on this trunnion as well, so I indented the receiver. I initially had some fit problems with the receiver edge and the trunnion, but a little grinding on the receiver allowed everything to seat perfectly. It is important to install the rear trunnion and stock assembly before attaching the trigger guard as the small rear rivet attaches to the stock assembly as well. To get my requisite number of U.S. parts, I had to replace the gas piston as well. The Tantal gas piston is custom. You can’t use a normal AK-74 or AK-47 piston!

Next came honestly the most technically challenging part of the assembly – installing the trigger group. The NoDak receiver comes with instructions on how to install the trigger group. This involves disassembling the burst mechanism so you can use it as a retaining plate and removing some of the guts from the selector (as it’s going to end up being cosmetic anyway because you can shoot the rifle any way you want as long as it’s semi-automatic). You also have to notch the trigger as the hammer spring does not also operate the trigger on the Tantal. Instead it has a separate trigger spring (which, confidentially is a real pain in the butt to install if you haven’t done it several times!). Once you get the trigger group installed, all that remains is adding the bolt and carrier assembly, spring, and top cover.

Apart from fiddling with the trigger group for a while, this build went together like a charm. All of the rivets came out perfectly. Magazines fit easily but snugly into the magazine well with no binding or extra force required. The whole build from “as received kit” to “final product” took me about 5.5 hours. The whole rifle will need to be refinished, but that can come later. All in all I’m extremely happy with the result!

Until next time!!!


Mikey D said...

I'm currently finishing up a Tantal build myself. It's my first AK build. Like you I've had to struggle a bit with the non-standard trigger group. Unfortunately, I managed to break the trigger spring this afternoon and I'm stuck until I can acquire a replacement (it's on the way).

The upshot is that my research indicated that one may use a standard hammer/trigger spring on a Tantal and thus eliminate futzing with the difficult separate trigger spring. I expect to be up and running in a few days when the new spring arrives.

In the meantime, I think your Tantal looks fine and I appreciate your posts here and at the AK Forum. I hope my initial range visit proves a laser as well.

Fingolfen said...

Sorry to hear you had trouble with your trigger spring. I like to go as original as I can with my builds, although I considered diving for an alternate hammer spring as I'm using a standard trigger group. Best of luck on your build!