What You Need to Convert a VEPR—StormWerkz and Bonesteel folders

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StormWerkz makes a niftly little AK to M4 folding mechanism that fits quite handily on the end of a Krebs adapter. (Some like it better than the Ace system). Rifle above features a Bill Rogers Super Stoc and an ERGO grip.

by Rob Kay

In the part one of this “conversion” series we looked at two adapters from Krebs Custom. With these adapters implanted in the VEPR’s receiver, you’ll have an option to attach a folding or fixed buttstock.


In this second article we’ll look at folders from StormWerkz and Bonesteel Arms—two companies that specialize in the AK platform.

Both are excellent products and provide you with two really good folding options for your VEPR.

Both items exemplify the type of creativity that characterize so many entrepreneurs in the AK space. In contrast to the AR 15  universe, which is dominated by much larger companies, AK-oriented businesses are one-man shows. They harken back to craftsmen of a different era.

It’s also the good old fashioned pursuit of the American dream. These entrepreneurs are dreamers and tinkerers. They are driven  more by passion than money. For the sake of these guys and their families, I wish them luck. Sometimes a good idea, some garage space, a CNC machine (and a good patent attorney) can go a very long way.

Despite the sanctions, the blooming of this type of creativity makes it a golden era for AK lovers.

Adding a StormWerkz Folder

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StormWerkz’ symmetrically sided wedge will wear evenly and last longer than the competition.

Storm Werkz came to my attention a few months ago, after having a conversation with a Hawaii AK builder who heaped praise on their AR 15 Stock Folding Mechanism.

His effusive comments led me to Josh Miller, the owner and founder of the Superior, Wisconsin based company. Josh makes makes handguards, scope mounts, rails and other “niche” products for marques such as Armalite, Ruger, Daewoo, Robinson Arms, FN and other brands. In addition to the folder, his other AK products include sling plates (for AK pistols) and scope mounts for Krinkoffs.

His AR 15 stock folding mechanism matches perfectly with the Krebs adapter. At first glance it looks to be a clone of a folder from Ace. However Miller reckons that his version is a notable improvement over the Ace version. The main difference, he notes, is the design of the wedge. (See photo at left).

The StormWerkz features a symmetrically sided wedge which Miller says will allow the locking mechanism to wear evenly and last longer. It’s available from his website https://stormwerkz.com/stock-folding-mechanisms/stock-folding-mechanism-ar-type for $75.

attaching the stormwerkz
Adding the StormWerkz folder was a piece of cake. Simply torque down the bolts, add a little Loctite and you’re ready for the bad guys.

To mount it, just add a little Loctite to the two 10/32 5/8” bolts that come with the folder and cinch it down to the Krebs adapter.

We thought the folder worked quite well–both functionally and aesthetically. It was easy to use and locked up tight at full length. It also locks up when folded. The stock was quite rigid and short of using it to hammer down rail road spikes, should be quite durable.

It feels very solid when shooting it.

Price for the folding mechanism is $75. Keep in mind you ‘ll need a tube, castle nut and endplate.


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Bonesteel’s folder is “plug and play”. Just pop it in the end of the receiver and bolt it to the tang. Comes with an adapter, folding mechanism, swivel and a milspec tube. Looks good too.

Chris Bonesteel, founder of Bonesteel Arms, is another “cottage industry” manufacturer of AK products.

His product line includes items designed for a variety of platforms including the AR 15, AK, Galil, PSL, Saiga, VEPR and VZ-50. This entails rails and muzzle brakes but he’s probably best known for his folding mechanisms. These include both Galil type stocks as well as folders that are integrated with an M4 collapsible stock.

With little fanfare, Bonesteel has received the attention of some of the best custom builders around. Definitive Arms, for example, uses a Bonesteel folder on their high end VEPRs and builds rifles for Copper Custom Armament owned by Tim Harmsen of Military Arms Channel. (Harmsen specifies that the Bonesteel folders be used). The Definitive Arms custom VEPRs fetch up to $2000.

The appealing thing about the Bonesteel M4 stock for the VEPR is that it’s what I call “plug and play”. It combines a folding mechanism with a milspec extension tube and a slanted adapter that fits into the back of the receiver. Just bolt the whole enchilada to the back of the tang (and add the pistol grip) and you’re ready to rock.

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It’s easy to install. Just tighten the screws and the grip bolt that locks in the pistol grip.

The milspec tube is pinned onto the folding mechanism and it’s exceedingly light–12.5 oz (just the hardware) and 19.5 oz or thereabouts with a buttstock attached. The “lightness” quotient is of course very important but doubly so with a VEPR which by definition is about a pound heavier than a typical AK.

Any weight savings is a blessing and it doesn’t hurt that the Bonesteel folder is machined from aircraft aluminum. 

By comparison, the combined (polymer) buttstock cum tube unit from SGM Tactical weighed about 2.4 lbs–significantly heavier than the Bonesteel product.  

Fit and finish on this item are superb–it has a shiny black anodized look that blends in perfectly with the VEPR color scheme.

The stock has six positions that will adjust to just about anyone–which is after all why you want a collapsible stock. If you really want to  get up close and personal you can bring the stock almost flush with the tang. It also has a “memory stop” feature that allows for an instant extension to where ever you want to set it. This is how it works: Each position has a threaded hole behind it for a cap screw to set a “preset” stop. Thus if you never go beyond number four position, you won’t be fumbling around trying to find the right spot.

We found the stock was really easy to manipulate without feeling like you were going to damage the hinge if you somehow tweaked it the wrong way. It tucks to right and folds closely to the rifle. Chris includes a Q/D sling swivel which also comes in handy.

My only “criticism” is aesthetic. There is a slight gap between the trunion and the receiver. Chris said that this was done on purpose to assure that the tolerances were correct.

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The Bonesteel system is handsome, well engineered, priced right. It’s plenty rigid when deployed. The finish blends in nicely with the VEPR.

In summary, this is a really cool looking, functional product.

It’s perfect for someone who wants to go the folder route, without having to buy an extra adapter and the other associated components. It’s a great all-in-one solution.

If you add up all the components of the StormWerkz/Krebs combo above, you’d pay $100 for the Krebs adapter and another $75 for the folder. That’s not counting another $40 for the tube, castle nut and endplate.

Contrast that with the total for the Bonesteel folder is $149.

Fixed Stock VEPR Option

For those interested in mounting a fixed collapsible stock on a VEPR there’s an adapter from Canis Design Group that might be of interest. This is a one-piece slanted adapter that fits on the back of the receiver and has a threaded female end for an M4 extension tube. All you need to do is screw in your tube, add the Buttstock and you’re in business. We have not seen or tested this product but it seems like a very practical way to go about mounting a fixed collapsible stock. Price is $65.

Photos courtesy of On Target Staff.

Questions?  Comments?  Contact us at ontargethawaii@gmail.com

Rob Kay writes about firearms for Hawaii Reporter and is the author of How to Buy an AK-47.
Read more of Rob’s articles on OnTargetHawaii.com