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View Full Version : Converting a metric reciver to inch mags


3Gunnah
August 09, 2017, 21:47
Before you guys beat me to death verbally about asking this question it's a convenience thing! There is a local Century Arms Imbel receiver gun that is completely inch pattern except for the magwell. I recently got rid of all my metric mags and do not wish to purchase more. I would like to have one type of magazine and one type only. This gun can be picked up very reasonably and I was wondering how hard or expensive it would be to have the inch cut made in the magwell?

tdb59
August 09, 2017, 21:48
The front ledge is possibly too thin for the mill cut.











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Vulcanator
August 09, 2017, 22:45
I believe Gunplumber used to do this mod. IIRC he said it was a pain in the ass. Considering all the machining he's done to fix Coonan and DSA receivers lately, you might be able to hit him up to do it for you.

tdb59
August 09, 2017, 23:05
I believe Gunplumber used to do this mod. IIRC he said it was a pain in the ass. Considering all the machining he's done to fix Coonan and DSA receivers lately, you might be able to hit him up to do it for you.

Probably not.


http://www.falfiles.com/forums/showthread.php?t=393847


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ActionYobbo
August 10, 2017, 06:50
done it a few times and its very simple if you have a mill and the correct size cutter
or you can do it the way i did my first one with a dremel and a steady hand.
you are not out to duplicate the inch cut you just need to make the metric cut wider and deeper

gunplumber
August 10, 2017, 07:23
Pretty much the key is the key (keyway cutter). Match height and make wider. Yes, if you cut to correct depth you will break through. But you don't need to go to correct depth. It is interesting that after machining the last 10+ out-of-spec DSA receivers, I'm feeling confident enough to do it for L1A1 conversions. Just like my defective Entreprise receiver back in '91 got me into fixing FALs, these defective DSA receivers have forced me to learn and develop new techniques.

E-mail me

DakTo
August 10, 2017, 07:59
Before you guys beat me to death verbally about asking this question it's a convenience thing! There is a local Century Arms Imbel receiver gun that is completely inch pattern except for the magwell. I recently got rid of all my metric mags and do not wish to purchase more. I would like to have one type of magazine and one type only. This gun can be picked up very reasonably and I was wondering how hard or expensive it would be to have the inch cut made in the magwell?

The cheapest way is to do it yourself with a Dremel grinding stone.
If the metric receiver is completely modified for inch parts it will include:
Charging handle rails cropped to accommodate a folding charging handle and round off base to match the rest of the receiver front.
Since the metric handle charging slide rails are too narrow for the inch charging handle slide narrow down both sides of the inch slide to fit.
Provide rear receiver cuts to allow the 2 inch stops to seat properly on the top cover.
The BHO and magazine release cross pin entrance hole may need to be widened partially to allow the cross pin head to fit and allow the cross pin to fit flush at the exit hole. (Not necessary on a DSA R1 receiver)

4markk
August 10, 2017, 09:15
Whichever method, be VERY careful not to lower the existing lower ledge otherwise you could screw up the function of the receiver (mags will sit too low).

gunplumber
August 10, 2017, 11:13
Whichever method, be VERY careful not to lower the existing lower ledge otherwise you could screw up the function of the receiver (mags will sit too low).

This!

That's why I bring the keyway cutter into the notch, raise it to contact, and then lock it into place. While I've done it with a dremel and grinder, it is very tedious and offers a whole lot more opportunities to ruin the receiver.

DakTo
August 10, 2017, 13:12
The lower horizontal bottom cut of the metric magazine notch is your red line and cutting lower may result in welding repair.

https://s20.postimg.org/7g1rrg5lp/001.jpg (https://postimg.org/image/qxwf7e2jd/)

3Gunnah
August 10, 2017, 13:57
Thanks for all the replies. Now I just need to make the deal. We shall see.

raexcct2
August 10, 2017, 15:38
Pretty much the key is the key (keyway cutter). Match height and make wider. Yes, if you cut to correct depth you will break through. But you don't need to go to correct depth. It is interesting that after machining the last 10+ out-of-spec DSA receivers, I'm feeling confident enough to do it for L1A1 conversions. Just like my defective Entreprise receiver back in '91 got me into fixing FALs, these defective DSA receivers have forced me to learn and develop new techniques.

E-mail me

Awesome.

hueyville
August 17, 2017, 14:11
It is interesting that after machining the last 10+ out-of-spec DSA receivers, I'm feeling confident enough to do it for L1A1 conversions. (Trimmed) these defective DSA receivers have forced me to learn and develop new techniques.

Aftermarket receiver companies will likely begin sending invoices for "training of advanced techniques in trouble shooting FAL receiver clones" along with a second line charging per unit for every new manufacture upper repaired. Line item two will read something like "supply out of spec upper requiring professional fitting". Likely see it as doing professionals a favor by forcing kitchen table builders like myself to send rifles out if actually want them to function. With luck future runs will have consistent errors allowing a jig for each required modification. All buyers can have uppers shipped "Care Of:" to save extra shipping fees and arrives to end user actually ready to assemble.

No disrespect intended or implied Sir, thought crossed my mind and had to let it out. If were possible to offer a flat rate service where non machinists that like playing with Lego Blocks for big boys can have compatible blocks instead of mixed box of U.S. Lego and Chinese Best Lock blocks. Since there seems to be a myriad of problems doubt a flat rate quoted up front could be set but if able to send all upper receivers off for a known flat rate so had verified proper foundation for build when started would be very tempting to send them all off before removing from original packaging.

DakTo
August 18, 2017, 07:54
Aftermarket receiver companies will likely begin sending invoices for "training of advanced techniques in trouble shooting FAL receiver clones" along with a second line charging per unit for every new manufacture upper repaired. Line item two will read something like "supply out of spec upper requiring professional fitting". Likely see it as doing professionals a favor by forcing kitchen table builders like myself to send rifles out if actually want them to function. With luck future runs will have consistent errors allowing a jig for each required modification. All buyers can have uppers shipped "Care Of:" to save extra shipping fees and arrives to end user actually ready to assemble.

No disrespect intended or implied Sir, thought crossed my mind and had to let it out. If were possible to offer a flat rate service where non machinists that like playing with Lego Blocks for big boys can have compatible blocks instead of mixed box of U.S. Lego and Chinese Best Lock blocks. Since there seems to be a myriad of problems doubt a flat rate quoted up front could be set but if able to send all upper receivers off for a known flat rate so had verified proper foundation for build when started would be very tempting to send them all off before removing from original packaging.

Current domestically manufactured FAL receivers with issues should be immediately sent back to the dealer for either correction or replacement under warranty. Having someone else correct the issue at your cost is your prerogative.
If you decide to tinker with the warranty part you are on your own. The necessity of shaving the barrel shoulder for fitting is outside the scope of the receiver's warranty.
Advice from a fellow kitchen table builder.

ExCdnSoldierInTx
August 18, 2017, 12:03
Ugh!

A DREMEL? In the hands of a novice like me?

W. E. C. S. O. G.

Now I'll wake up with chills tonight, I know I will.