Century AK-47 Bull Pup Quad Rail Modification Thread

[Boba Debt]

This thread will be dedicated to the modifications required to turn this:

27" Long / 17" LOP / 7 pounds unloaded


Into this

29" long / 18" LOP / 8.6 Pounds Unloaded



PLEASE, do not discuss the function or quality of the bull pup kit/parts. That has been discussed in length in multiple threads about these rifles. I would like to keep this thread focused on the just the modifications I made to the factory gun.



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This build thread is base on using a factory built Bull Pup AK-47. There is a KVAR kit available in limited supplies but I already have an turn key Bull Pup that I purchased from J&G for $400.


Obliviously there are a few parts that you must have to build this rifle but some are interchangeable, such as the Flash Suppressor, Vertical Grip, etc.

For the purposes of this build thread I will speak about specific parts, this is not an endorsement for that part, it is just what I used.



Here are some of the parts that I will use:

QUAD RAIL ASSEMBLY

• UTG Saiga 12 Quad Rail ($90) *
• UTG Saiga 7.62 Quad Rail ($70) *

VERTICAL GRIP ASSEMBLY

• 13 Slot 1" Riser ($15)*
• Tapco Stubby Vertical Grip ($18)

MUZZLE ASSEMBLY

• AR 15 Birdcage Flash Suppressor for AK-47s ($10)
• 6" length of 1/2" Electrical Conduit *

BUTT STOCK EXTENSION

• 1/4" x 3" x 6" Aluminum Plate
• 1" Fender Washers
• Tapco Butt Stock Pad ($10)

ADDITIONAL ITEMS YOU WILL NEED
Various Button Head Allen Bolts
Back Up Front Sight
Scope


Although I have no intention of offering a "KIT" I can help you acquire the items marked with an asterisk and I would be willing to do some of the modifications to the quad rails.


This build thread will be slow paced, but very through. Please feel free to discuss the current or posted steps but refrain from discussing the future steps as it will just bog down the discussion.



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MODIFICATION OF THE FRONT END

There are several things I don’t like about the front end of the factory rifle. The extended front sight block sits way too high and I had concerns that it would catch on stuff and be easy to knock out of alignment. I decided to remove it and go with a rail mounted optic and back up sights. The Slant Cut Compensator doesn’t do much for a semi-auto which is why I replace it with a $10 Bird Cage Flash Hider.

To facilitate these changes I performed the following work:

REMOVAL OF THE FRONT SIGHT BLOCK EXTENSION

1. Remove the Slant Cut Compensator by depressing the retention pin and turning it to the right until it is off the barrel.
2. Use a 7/64 Allen wrench to remove the Forward Hand Guard.
3. Remove the Front Sight Post from the Front Sight Block Extension.
4. Remove the small set screw from the front of the Front Sight Block Extension. I didn’t have an Allen wrench that was small enough, so I just used a #0 Phillips screwdriver.
5. Use a 1/4" Allen wrench to remove the Front Sight Block Extension Bolt.

You should be able to remove the Front Sight Block Extension at this time. I installed the original Front Sight Post into the original Front Sight Block so it would not get lost.


REMOVAL OF THE FRONT SIGHT BLOCK

1. Use a 3/32" pin punch to remove both of the Front Sight Block Retention Pins.
2. Use and Arbor Press to press the Front Sight Block off of the Barrel.
3. Reinstall the Retention Pins to prevent the lose of the pins and the muzzle device retention pin parts.

This is an image of my $30 arbor press. These are not that expensive and have many uses in a shop.





Now that the Front Sight Block is removed you will have 2 grooves on the top of the barrel that can be expensive to repair so I just cover them up with an inexpensive barrel shroud.



I use a 4" length of 1/2" galvanized electrical conduit which is available at most hardware stores.

Before I install the shroud I do a couple things to prep the rifle for future work:

I remove the Bayonet Lug with a band saw and grinder since I have no intention of ever installing a Bayonet. This step is not required.

I remove the Sling Loop that is part of the Front Hand Guard Retainer with a Dremel and a cut off wheel. This is required to fit the Quad Rail to the rifle. I think you could modify the rail to fit around the Sling Loop but I intend to use a rail mounted Sling Swivel.

Once that is done I paint the bare area of the barrel with Rustoleum High Temp Flat Black Paint. I heat the metal with a heat gun and apply the paint. I also bead blast and pre-paint the barrel shroud.

Once it is cool I slide the shroud onto the barrel and use the Bird Cage Flash Hider to secure it in place. It fits tightly so it should be pretty much centered once you install the Compensator.



Not only does the shroud hide the grooves but it also give the front end a thicker Bull Barrel appearance.

______________________________________________________________________________________________

MODIFICATION OF THE BUTT STOCK

The factory rifle has a 17" length of pull which sounds long but for this type of weapon it's not a problem. However, I didn't like the rectangular unfinished look that it had and I was pretty sure it would not be comfortable to shoot.

I used a Tapco T-6 butt stock to create a wood template. I used the wood template to mark a 1/4" sheet of T-3 aluminum. I cut out the rough shape with a band saw and finished it on a belt sander. Then I bead blasted and pre-painted it.

I use 8 fender washers and 2 self tapping screws to attach it to the original butt stock. The fender washers create a gap that gives you some place to tuck the edges of the Tapco Butt Stock Pad into.

The butt stock extension adds 1" to the length of pull but it still doesn't feel wrong.





______________________________________________________________________________________________

 

[GunsBeerFreedom]

Are you using both rail assemblies or is this an either or type of thing?

 

[Girodin]

I definitely like the look of the modified gun much more than the century bullpup. I look forward to seeing how this project goes.

 

[boricua9mm]

Bullpup'd AKs aren't my cup o' tea, but you've done one helluva job on that one! Bravo!

 

[Boba Debt]

I just added the "Modification of the Front End" section to the original post

If anyone is interested in the parts I removed I will sell the Slant Cut Compensator for $5, and the complete Front Sight Block for $20

Send an email to [email protected] if you're interested.





I work a lot. I also do home renovations in my spare time. In the very little free time that I have I work on my guns.

This thread is cross posted to 5 different forums

I asked you to refrain from asking question about future parts of this build and I asked that everyone keep this thread focused on just the build aspect.

I will ignore any question that do not pertain to the posted info.

I will also ignore any useless off topic discussions within this thread.

I'm not trying to be a dick but I just don’t have the time to discuss the drawbacks of the trigger or the possibility of the gun exploding or if the state senate is going to make this type of fire arm and AOW or the countless other discussions that will crop up.

I think it is rude to clutter up a build thread with this type of noise.

If it get to congested, I'll just stop posting info to this thread and not worry about it.

 

[Maverick223]

Not a big fan of the kit, but I have to admit that you definitely improved upon the aesthetics if nothing else.

You may want to consider torquing the flash suppressor down to tension the bbl. This can often aid in accuracy, and prevent "barrel droop" as it heats up. You will need to add a few drops of Blue (med. strength) LocTite to prevent it from loosening over time.

 

[Bigfoot]

I'd rework that plastic extension that you attatched the recoil pad to and remove two inches from the LOP. My bullpups have 15" LOPs and I'm working on shortening them.

OP, you sure make long posts typing at length about what subjects you're not going to post about. Was that rude?

 

[Boba Debt]

I just added the "Modification of the Butt Stock" section to the original post.

LOP isn’t an issue for me.

Short LOPs tend to make people stick their elbow out. A bull pup is CQB weapon so keeping your body tight is important. The long LOP tends to make you drop your elbow in toward your body.

I also like that I can maintain complete control of this rifle with one hand

 

[jojo200517]

Mine wasn't terribly uncomfortable to shoot as far as the butt stock part. You ground off the bayonet lug so it can't burn your left hand off like mine did stock, I put a clamp on 5 slot rail and a foregrip on mine but its too far forward and would lead to toasty knuckles. I need to take that little front part of the clam shell off and put it between the gas block and the other part of the clam shell kit.

The real question is have you shot it? My trigger got horridly hot. I had to grind some off the part that the wire hooks in (its plenty thick enough) so it didn't rub against the barrel. Also put a small washer on the trigger pin on the opposite side to space it over and keep it from sliding back against the barrel.

Edit, I had a sight that looked very similar to the one you have, and while the AK has much less recoil it only lasted about 3 shots on my shotgun before it would loose sight in.

 

[JTH]

Just out of curiosity, have you been able to shoot, say a 20 round magazine, without it jamming?
JT

 

[Boba Debt]

I don't own any 20 round magazines

 

[Dave Markowitz]

Very neat project.

The only suggestion I have is that while the rifle looks like a rugged piece of kit, that red dot sight is going to be relatively fragile. You'd probably be better served with a better unit.

 

[smince]

What's it do that these won't do just as well (or better)?

 

[wally]

What's it do that these won't do just as well (or better)?

Be shorter in overall length when shouldered.

Bullpups are mostly a novelty for us civilians.

 

[jojo200517]

JTX, mine didn't jam any out of the first 4 30 rd mags that have been thru it. It did however require cooling off to keep from burning myself on it. I haven't tried it with improvements to see if it still gets hot where I'm holding it.

As for smince,
* it only comes in black so it does a great job of upsetting people with green AK's and SKS's
* it will fit in much smaller spaces due to short overall length, while maintaining barrel length and not being a SBR
*it can be fired pretty decently one handed due to grip being more toward the center of the weapon(i found this out when i burnt my left hand on the stock one)
*it does a great job at irritating left handed people when you tell them sorry you can't shoot it it'll knock ya teeth out

However it can't really use stripper clips.

 

[Beaux Nehr]

Wow, that looks really great, OP!

 

[Boba Debt]

*it does a great job at irritating left handed people when you tell them sorry you can't shoot it it'll knock ya teeth out


Now that's funny :lol



I have a converted full size Saiga and I'm going to buy a second one soon. I love tinkering with my guns and Saigas are fun to tinker with.

The idea of the bull pup just intrigued me. I wanted to buy one of these for a long time but wasn't going to pay $650+ for it.

When they hit $400 at J&G I couldn't pass it up, so I bought 2. I pretty much buy 2 of every gun I own, I have a son and a step-son and don't want them fighting over my guns when I'm dead. That may sound weird but I have been told my magazine is a few bullets short of being full.

So when I got the bull pups, I fam fired one and loved the way it handled. Sure the safety is a pain but personally I don’t set the safety until I'm done firing or when I pull it from my shoulder. Mag changes are not an issue, the grip acts as a guide and I think I can swap mags on the pup faster then I can on my converted Saiga.

The only hang up I had was the lack of a good rail system. So I hit the shop and built one for them. I have to get a few issues worked out but once I'm done I'm sure love them.

Realistically this rifle is for confined spaces. I would not select this rifle for a target that was 100+ yards out, just as I wouldn’t grab my 7.62 Saiga for a 400 yard target, that would require my Savage FCP-K which is chambered in 308. Each gun serves a purpose and the construction of this rifle suits it purpose very well. It's a tight, easy to control weapon that delivers a good punch.

 

[rd2007]

This was a hella improvement Boba. What tools did you need? I Know I need to get a Dremel for pretty much anything.

 

[Izzy77]

and if you have a KB you will wish you had kept the bolt and chamber farther from your face.

Making a rifle not designed from the ground up with safety factors into a bull-pup is plain STUPID.

( non spring loaded firing pin, slam-fires, etc., etc.)

 

[Boba Debt]

I'm going to cover the tools required as I do each step.







Century has sold 100s of these and have not had a problem with them blowing up.

 

[Girodin]

Century has sold 100s of these and have not had a problem with them blowing up.

There are even more with the same AK action that simply weren't built into bullpups that don't have issues with blowing up either. The critique is not that they are likely to blow up but rather that should it happen it might well do more damage to the shooter with his face right over the action. I think that is fair to say it is rather unlikely it will occur.

 

[wally]

Good thread, got me thinking about mine again, I had an ATI upper hand guard with rail left over from a project where I only changed the lower hand guard so this thread inspired to try adding a red dot to mine.

Here is the result, not so elaborate, but much more functional than the stock configuration. My trigger doesn't get hot but the front was too hot to handle after half a mag or so. An AR rail, some shoulder washers, and epoxy putty let me put on the vertical grip which solves the heat problem. I've played with a few different vertical grips and concluded I don't really like them, but this "5-position" cheapie works very well, the photo shows the way I actually prefer to use it when shooting.

If only the trigger was better. Mine is very spongy and tough to predict the "break" which hinders accurate shooting, but it handles well and the Sightmark Aimpoint-look-alike is a very serviceable $80 red dot and gives a nice co-witness with the irons. I adjusted the dot to the irons and was only a few clicks off.

 

[Izzy77]

AK's esp. the non spring loaded firing pin types can KB on rare occasions from stuck firing pins, slam-fires, etc. My buddy shooting the 223 SAR-3 ended up with a KB in 2001 ( ok a romanian 223, but crud happens).


http://www.youtube.com/watch?v=L4nAU0e8lhQ


http://www.youtube.com/watch?v=lfIOi6Z16zQ


I love AK's, but it was not designed from the ground up as a bullpup, and lacks the built in safeties of a Styer AUG, or other ground up bullpups.

 

[wally]

can KB on rare occasions

Frankly, I'd worry more about getting killed in a car crash on my way to the range from some idiot yakking on a cell phone.

 

[Boba Debt]

MODIFICATION OF THE REAR SIGHT

The Rear Sight is used to support the back of the upper rail. It also must be removed to remove the Gas Tube. At this point in your build it is a good idea to start the modifications to the rear sight:

1. Remove the M4 Allen Bolt
2. Remove the roll pin with a punch
3. Cut the top part of the sight off with a band saw or hack saw
4. Grind the base until the upper skeletal structure is flush with the flat area on the base

Once the gas tube is modified you can reinstall the rear sight base with the Allen bolt but I don’t re-install the roll pin until I have painted all of the components.

______________________________________________________________________________________________

MODIFICATION OF THE GAS TUBE

The Upper Hand Guard Flanges must be removed for the installation of the Middle and Upper S-12 Rail Sections

1. Remove the Gas Tube
2. Identify the spot welds. On the back flange they will look like round dimples about 1/16" in diameter. On the front flange they are on the raised ridges of the splines
3. Use a grinder to cut about 1/2 way through the spot weld. It is not necessary to remove the entire spot weld at this time.

1. After you have ground all of the spot welds on the flanges use various pliers to "tear" the them off of the tube

1. Grind the remaining part of the spot welds flush to the tube.
2. Use a 1" belt sander to blend the welded area into the tube.

When you are done your tube should look like this.



At this time you can paint the tube and re-install it or you can wait until everything is modified and paint everything at one time.

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