OK, guys, here it is.  The first installment of my Pistol Caliber AR projects.

First, lemme say THANKS to Circuits, JAFO, Kaliburz, NordicG3K, and especially Gloftoe for their help, input, loans, and donations (JAFO) for this project.

So, what did I do?  I took an Olympic Arms 9mm setup--which uses either the costly ugly STEN mags with the square pipe section welded to them or the inexpensive but personally annoying SOCOM block--and switched it to a system that uses the existing AR mag catch.

First I took a Colt two-piece mag block and modified it to fit the STEN mags.  The front block looked like this:



And now it looks like this:



I then took the rear block, which looked like this:



And modified it to look like this:



Then I installed the blocks into the lower, fitted the mags in the appropriate place, and notched them.  Here's what that looks like:



As you can see, I had to take the "wings" of the feed ramp down somewhat to allow the bolt to clear them.

This is what it looks like all closed up and ready to test fire:



The extra space that the cartridge needs to travel to get to the Olympic system forcing cone turned out to be a non-issue.  So far, feeding has been flawless.  Another fringe benefit of this modified system is that the rear block sits right underneath the ejector-spring setup that Oly uses, and acts as a sort-of shield, protecting it from any damage from over-insertions that can happen with the Oly-modified magazines.

This project was really an experiment to see if it would work (though Circuits already proved that it does).  Now that I've experienced it myself, the next project--due to be finished in about a month--will prove very interesting.

Way to go Corvus!  Lookin' good.

Nice. [:)]

So when are you going into business making these?

Cool.

(On that ASA measurement, I can't find my punch set to take the pin out.... will look harder....)

[ROFL2]

Into business doing *this*?  Can you say "Dalphon?"

[ROFL2]

Don't look too hard: I finally found someone at ASA who would give me the exact measurement.  he said to call back in a couple days and he'd have it off the drawings by then.  I'll keep you posted.

[:D]

Well that is  pretty neat-o. Being an Oly owner you have my attention.  You did a hell of a job.  I hope the next project goes as well.

I do have an Oly Arms modified STEN mag for sale now, if you are interested.  [:D]

[img]http://users.connecttime.net/www/clouglen/Oly9mm.JPG[/img]

I talked to the ASA guy yesterday, and he gave me the measurement.  So, no need for you to find those pins now.  But thanks, anyway.

The project involving the ASA block (7.62x25) will follow the other project (due in another month) shortly.

Sweet.

What keeps it in the lower?

Either they are perm. pinned in or it is held by a set screw.  That was how the 2 piece blocks were retained in the mag well.

In the case of this setup, one hole was drilled into the front of the magwell, which continued (by use of a very long bit) into the back of the magwell.  The holes on either end of the magwell were then tapped.  The rear block is held in by a socket head cap screw (screwed in from the front of the rear block, and recessed into the block) and the front block is held in with a socket button-head screw.  So, the rear hole is completely interior, and the front hole is very unobtrusive.  And in the case of both blocks, they are securely held in place by using screws pulling in the proper direction.  No slippage here at all.  Now, of course, I am using a dedicated lower, so drilling a hole or two into the magwell is OK to do.

Well, Corvus, you inspired me.

I hauled out a spare set of the old JRW blocks I had and started whittling on them.  I took more off the rear block than you did and took metal off the rear of the front block instead of the front, but the net result is now a Colt (not Oly) that uses Lanchester mags.  I still have to tune up a few things, but so far functioning has been flawless and the blocks still stay in place with the original set screws.

Thanks!

Lanchester mags = just like Stens

Mine stays w/ the set screws too.

Note that Oly is working on some new stuff to be out in the next couple months...  Last round open, uses commonly known pistol magazines, etc.

I will pass more on when the time comes.

whatcha want for that sten mag?

That Sten mag is still for sale...

Where can I get a 2 piece mag block like that to modify?  All I've seen is one piece blocks from Adco or ASA.  Will this setup work with a Colt style upper?

I got my Colt 2-piece mag blocks by advertising on [url=http://subguns.biggerhammer.net/under500.cgi]Tom Bowers Parts Board[/url] that I wanted two sets.  Go a really good price for them.

Yes, this will work with a Colt setup.  Check the tacked link on how to do it [url=http://www.ar15.com/forums/topic.html?b=3&f=15&t=136191]Right Here.[/url]

Is it possible to modify a 1 piece block?  Has anyone ever done it?

The sten mags are too wide to fit with a 1pc block.

You'd have to shave the block and that would lead to a potentially very fragile block; or shave the mags to fit inside the 1pc block, which would leave you with wierd looking mags.

If you didn't mind wierd-looking mags, it could be done, though.

Finally was able to get this 9mm setup out today and shoot it.  It functioned perfectly.  I took a few STEN mags out with me: my best-fitting one, a middle-of-the-road one, and my worst-fitting one.  They all worked perfectly.  It was awesome.  And accruate, too.

[:D]

Thanks.