The opinions and descriptions here are my own and are not to represent an official opinion of this web site. I am not a lawyer, this is not legal advice. Seek your own understanding with the California assault weapon laws prior to purchasing or assembling your own rifles.



Several tens of thousands of “off list lowers” have flooded California following the California Supreme Court’s “Harrott decision”. There are many ways to legally assemble these lowers, recently I purchased and assembled a kit from Ten Percent Firearms of Taft California. The $41 kit consists of everything needed to make an off list lower California compliant and quite functional. There are three separate items combined in this kit: a Prince50 magazine lock kit, a Watsons Weapons extended take down pin, and finally a Bushmaster 10 round magazine.



The Prince50 magazine lock kit consists of four parts: a specially modified magazine catch button, a long hex screw, a short hex screw, and a matching hex wrench. The kit comes with a simple instruction sheet. The manufacturer explains that “this lock kit has not yet been approved by the California DOJ. It meets the requirements as set forth in California law only. Please continue to check the California DOJ firearms division for any emerging requirements.”



A close up of the modified magazine catch button shows a second hole carefully drilled and tapped into the catch’s body. This allows for the use of a longer screw which bottoms out in the pocket of the magazine catch button keeping the button from being pressed and locking the magazine into place. To install you simply remove the old magazine release and put the new one in place. Remove the magazine and press the catch until you can grab the lever opposite of the catch that holds the magazine in place. Rotate the latch counter-clockwise until the catch comes off. Putting the Price50 into place is as simple as removing the old one.



The manufacturer lists eight different configurations of the kit’s use, all of which meet the requirements of California law. They recommend using configuration number 8.

1. Spring, long screw.
2. Spring, long screw, glue.
3. Spring, long screw, small screw
4. Spring, long screw, small screw, glue
5. No spring, long screw.
6. No spring, long screw, glue.
7. No spring, long screw, small screw.
8. No sping, long screw, small screw, glue.



The magazine can be removed with the use of the included hex wrench and returned to normal function should one leave California in about ten seconds from configuration 1 listed above. I tested the kit in configuration number 3 and will likely use the thing in configuration 4 with a dab of green locktite.



From the left side of the rifle there is no difference in appearance. Dang, what happened to the serial number?



Once the magazine is locked into place the rifle needs to be “shotguned” open to reload the ten round magazine. To make pulling the rear take down pin out Watson Weapons makes an extended take down pin which has a prominent head to it which makes gripping it with the fingers very easy.



Once installed it sticks out just enough to get a finger hold on the thing to allow you to pull the take down pin with ease.



The third and final part of the Ten Percent Firearms kit is a fine quality Bushmaster 10 round magazine. The magazine is locked closed and Bushmaster recommends against disassembly. The follower is an anti-tip green one. The fit and finish are standard Bushmaster perfection.

My overall impression of this kit is very good. The Prince50 kit allows California compliance without permanent modification of the weapon. The Watson Weapons extended take down pin is a simple design and works well. The Bushmaster 10 round magazines have been know to function well. Ten Percent Firearms has assemble three simple to use parts to make your off list lower California compliant.

Ten Percent Firearms can be located at www.tenpercentfirearms.com or by phone at (661) 765-6899. Shipping was very fast - three days to my door.

See this thread for SRBtactical Spring Retaining Bracket solution:
www.ar15.com/forums/topic.html?b=8&f=11&t=238419&page=1

Next I'll do a spring retaining bracket (SRB) which replaces the pistol grip allowing detachable magazines to be used in an off list lower. That guy ought to be here next week early. I've also got another Bushmaster lower kit coming and my good friend Jon of "Jon has a long mustache" is mailing an upper to me,

Do not even expect me to go shooting in this weather to try these things out please!

Quoted: You Navy guys get too far from that cool ocean breeze and just wilt, eh?

108 here for an expected high tomorrow - I don't even want to think what it's going to be like in the high desert ... Phoneix/Las Vegas hot!

Quoted: Can the rifle be converted back to a detachable mag configuration with hand tools?

Yes - a hex screw needs to be removed for configurations 1-4. In configurations 5-8 you'll need to put the magazine catch spring back inside the pocket under the catch.

Quoted: Hope it helps someone out there.

Thanks for the addition. The Bushmaster web site says do not dis-assemble ... but it looks like its possible. Since the only thing holding the magazine in place is a hex screw if the body were to become damaged it's simple enough to repair. Remove the pistol grip, loosen the screw, pull the magazine, pop a new magazine into place, return the screw, and now put the pistol grip back in place.

Quoted: Paul, what kind of camera did you use taking those pictures?  They are amazing.

Thank you very much.

That's a five year old Olympus E-10 with a close up diopter lens using a bounce flash. The thing is only 4 Mb worth of resolution but has excellent glass. It's really not the camera that makes the pictures ... it's the photographer.

I'm upgrading the camera with a Nikon D70s with matching 18-200mm Nikon lens and flash but I'll still likely keep the Olympus around for awhile. I've taken close to 20,000 pictures with it and it's having trouble with its auto-focus and its flash bracket. Still works great for manual focused shots and I have a bounce grip that works perfect.

Quoted: So, does this kit come with a plastic mag release button or a metal one?

Metal.

Quoted: Nice kit.  I'll need 4 for my off list lowers.  But I was wondering if this kit would be ok to put on my DOJ approved Vulcan receiver with the crappy mag?  I bought mine before they started using glue or epoxy.

As long as it's an off list lower (the list is pinned in this forum) and you don't create an assualt weapon you should be fine.

Quoted: You should love the Nikon D70s.

I will if and when I ever get the darn lens! I put it on order back on May 26th ... and it's estimated delivery is late August! I tried to buy the Nikon 70-300mm lens two weeks ago and the company canceled the order the day they were due to deliver (Ace Digital). So I've ordered a third lens - a Sigma 10-22mm ultra-wide angle lens from B&H photo which is due here Tuesday.