Custom 10 and 15 round Mrod mag *NEW* Final Version for Sale

[scharfe]

One issue I did not foresee when converting my mrod to a bullpup and me being left handed is my cheek rests squarely on the less than convenient factory magazine sticking out of the right had side of the gun. My solution, make a left handed magazine for my left handed self.

[/URL]

1st Step - A couple of hours with calipers and solidworks to duplicate the factory magazine.
2nd Step - Mirror all parts to create a left handed magazine.

3rd Step- Make a plan, write some cnc programs and start machining.

I cut a block of acrylic down to my desired size, first program is the for the "front" of the magazine housing.

[/URL]

I used a block .25" thicker than the magazine housing so I had something to clamp into the vise.
1st step done.

[/URL]

I then machined another piece of acrylic so I could flip the magazine over and machine the back side. The hole in the center is for a screw to screw from the bottom side into the center of the magazine.

[/URL]

I was a bit to generous with my offset so I had to shim around the part with some paper.

[/URL]

After running the second program, the "raw" housing is done.

[/URL]

Next I wanted to make the housing clear, because...well why not?

I started with 320 grit sand paper then, 600, 800 and finally 1200 all wet sanded. I next used NOVUS compound 3 (from McMaster) and a car buffer to polish the housing. And finished off with some NOVUS compound 1. The stuff is quite nice.

[/URL]

After cleaning up the print I put all 3 parts together and they fit well together.

[/URL]

Unfortunately all things needed to be mirrored for this to work, including the  factory left hand torsion spring.

[/URL]

I couldn't find anything even close to working for this spring. So I made one my on my lathe.
[/URL]

And a couple pics with a loaded magazine. I put 10 rounds through it with no issues. Pretty happy with the results. Im going to have to machine the inside piece out of acrylic also though. The 3d printed part is just not up to my standards.

[/URL]

[/URL]

[/URL]

[scharfe]

And some pictures of main finished aluminum part that does most the work. And some explanation to what I consider improvements.






Improvements over stock.

1. I added a full circle lip around the top of the inside piece. The hole is just barley big enough to let a perfectly circle pellet skirt through. If the skirt is damaged or misshapen it wont go trough the hole. If it is skirt shape is slightly off the hole will reshape the skirt to its proper shape. (A very small bevel on each hole keeps the aluminum from removing material from the pellet.) This eliminates my need to sort out pellets as much. I have yet to have a stray flyer with this magazine. 



2. The extended the center hole down with a shaft for 2 reasons.(seen below in center of part)
 A. The factory hole only makes contact on the center shaft with a thin section of material. The extended shaft takes out a lot of play in the magazine, allowing for more consistence rotation, more consistency could lead to better accuracy.
 


B. The factory spring, as it tightens can rub on the stationary shaft of the magazines black housing. The on and off friction can cause inconsistent torque. The extended shaft only allows the spring to rub on the moving shaft, allowing for more consistence rotation, more consistency could lead to better accuracy.

3. I shortened down the inside geometry to only accept .3" and shorter pellets. It is designed around all my favorite pellets, JSB Heavy, JSB RS, H&N Sport Field Target and Crossman ultra magnums. All these fit perfectly where the skirt of the pellet is always held perfectly center by the back full circle. Again allowing for more consistency.

4. I tightened up the hole spacing,refined semi circle geometry and made the stop part smaller so I could get more pellets in a smaller diameter than if I would have used the same method as the factory mag.

And here is the pictures of the 15 round mag. Consists of 6 parts.

External Back Housing
Front Cover
Inside wheel
Spring
.125" shaft insert (allows front cover to move the inside wheel when rotated)
4-40 ss screw



And the assembled magazine.






I personally really like the clear and aluminum combo on the gun. I suspect the aluminum to eventually run some of the back off my bolt but don't really care. It wont be in there for long anyways.



And one last picture for the other materials and size comparison to a factory 10 round size.

[/URL]

thanks
Bob

[clgraham82]

Amazing!  Great job!

[jvanschoonhoven]

That turned out really good

[YEMX]

Hmmm... Perhaps this will lead to another vendor??     These mags look great!!  Have you ever thought about going in the opposite direction- down to say, a 7 round mag?  Like Theoben did?  Pics:

7 shot Rapid mag:


Bottom two pics, size difference between the standard and 7 shot mags:


I always liked the lower profile of the smaller mag myself. 

[Hobbyman2007]

The real question is when are we going to be able to order these? The second question is will it fit a BNM breach for the 22## platform?

[YEMX]

...will it fit a BNM breach for the 22## platform?

Oooh, THAT's a good question!!!  I hadn't thought of that! 

[Whome1525]

That is some very nice work.

  Steve

[the sloth]

As a fellow lefty and Prod bullpup owner, I feel your pain! I've just been dealing with the mag sticking into my cheek. Would you consider making a few of these for sale, and maybe for the Prod? I'd buy one for sure!

[Habanero69er]

Nice work.

[davelogan]

That is just......SO COOL!!!!  Amazing!!!

[PakProtector]

Droooooool.

I hope you decide to offer these for sale. How about for the big bore folks? 7-round 30 cal and able to swallow boolits .700 long?
chees,
Douglas

[scharfe]

Hmmm... Perhaps this will lead to another vendor??     These mags look great!!  Have you ever thought about going in the opposite direction- down to say, a 7 round mag?  Like Theoben did?  Pics:

7 shot Rapid mag:


Bottom two pics, size difference between the standard and 7 shot mags:


I always liked the lower profile of the smaller mag myself.

Ive never thought about going smaller honestly. I personally don't have a need for one. But on the other hand don't mind a challenge.

[scharfe]

The real question is when are we going to be able to order these? The second question is will it fit a BNM breach for the 22## platform?

I don't know honestly. I have never gotten ahold of an BNM breach. But if it will accept a factory mrod magazine, it should accept mine.

[scharfe]

As a fellow lefty and Prod bullpup owner, I feel your pain! I've just been dealing with the mag sticking into my cheek. Would you consider making a few of these for sale, and maybe for the Prod? I'd buy one for sure!

Yep, I feel your pain is my exact thoughts haha.  Im starting to consider making a couple if people really want them. Unfortunately all I have is a 22 cal Mrod, so unless other variations of calibers or guns or aftermarket breaches use the same geometry as my mrod I wont be able to design and test them. I would love an excuse to buy more guns ,but might have to sell a couple mags for that haha.

[scharfe]

After hearing more interest from people in buying these than I expected I decided to try to write some more efficient programs on the cnc to see if I could feasibly make these fast and cheap enough so that they were NOT the $75 magazine that my initial unrefined programs indicated.

Im definitely enjoying the challenge and I am already on Rev 3 of the magazine. This one is shooting like a dream, I don't think Im going to be able to go back to the factory one. And Ive already decided to scrap my first left handed design based off of the factory mrod and decided to create a 10 round magazine based off of my original 15 round design.


While I was running some programs I had some free time so I decided to clean up some of the aluminum internals, I did a brushed satin and polished finish. They look a bit nicer than my first prototype.




Hopefully I will have some pretty machined prototypes of the 10 rounders soon. Thanks everyone for the comments and interest.

[Habanero69er]

Okay, now you've stepped in it! You just created a lot of work for yourself.

[William]

The real question is when are we going to be able to order these? The second question is will it fit a BNM breach for the 22## platform?

Why sure they will fit the BNM breech, I have one and it uses the 22 cal Mrod mag, so there is no reason for it not to work!

With my Mrod 10 shot mag installed in my BNM Breech I have about 0.48" clearance from the top of the Mag to the bottom of the Scope (Scope is 30mm UTG 6-24x 56mm) using High Mounts and the clearance from the bottom of the mag up to the bottom of the scope is 1.80" Now this is using High Mounts, so low and medium are going to be different.

The 10 shot mag itself is 1.34" in height.

There actually may be more room due to the Mag actually sets slightly off to the side a little...

So, I believe a larger 15 shot or a smaller one will work fine on a BNM breech...

William

[YEMX]

I like the idea of a smaller mag because:

A)  No worries about interference shooting a bullpup, as far as cheek placement
B)  Could mount the scope lower to the barrel
C)  I like the lines better...
D)  If I need more shots than 7, I'll just carry more mags.

I've never personally been in a hunting situation where I needed that many shots accessible at once.  I can deal w/a magazine change. 

AWESOME JOB AGAIN!!!   

[William]

The real question is when are we going to be able to order these? The second question is will it fit a BNM breach for the 22## platform?

I don't know honestly. I have never gotten ahold of an BNM breach. But if it will accept a factory mrod magazine, it should accept mine.

The BNM Breach Uses the 22 cal. Mrod Magazine.

So it will work.

Willaim