Do any of you know of a drop in .45 conversion block that can use M3A1 Grease gun magazines? I know that American Spirit Arms makes one for their 9mm. The magazines that Olympic Arms sells .45 is $65.00, and only hold 16 rounds. The M3A1 Grease gun magazines hold 30 rounds, and sell for $16.50. I have written to American Spirit Arms and asked if they would be making any of these for the .45, and have not heard from them yet. This would be very nice if they would make one. I think everyone on this forum should wright to them and request that they make a drop in .45 conversion block. Thank you for your help.

John,

Bad news.  The unmodified Grease gun mag will not come close to fitting into a standard ar15 magwell.  If you did modify it, in this case narrowing it to fit the magwell, it would no longer work in the grease gun because the mag catch would no longer work.  This in the eyes of the ATF is manufacturing a new postban high capacity magazine.  

However, there was a company some years back that made a sidefeeding 9mm and 45acp upper.  I believe the 45 used a grease gun mag or a thompson mag.  This discussion on the sidefeeding uppers was brought up on this or one of the other forums.  If there's enough interest I'm sure that someone would tool up for it.  

As a matter of fact, there is an artical in Small Arms Review on a 9mm side feeder.  It's been a few months ago.

Yep, this is current ATF procedure.  So, my question is this: how can Dalphon get away with their modified Grease Gun mags, since they circumcise them, squeeze them, and weld a big ugly block on them?

And Olymipic Arms modifies Sten and Uzi magazine for $65.00. How do they get around BATF?

My question too.  If you peel off the steel reinforsement at the top and squeeze them like Dalphon does without welding on the addaptor they are about the same size as a Sten mag and would probably work in the Sten mag addaptors.  Hmm.  Anyone know how to get legal clarification besides getting arrested?

Cant answer for the sten mags.....But the modified uzis to work in the colt system will Still work in an Uzi so your not making a "new" hi cap mag,,,or so the ATF says

The Sten and Uzi magazines that Olymipic Arms makes ,and M3A1 Grease Gun magazines that Dalphon makes or modified and will not go back in to the original gun that they came from. I thought that was illegal. I guess not. In any case sense there is on drop in conversion block for the .45 M3A1 Grease Gun. I guess I will buy the Dalphon modified M3A1 Grease Gun 28 rounds magazines for $79.00. Thats 12 more rounds than Olymipc Arms`s magazines.

For the Uzi 45 mags and the Sten mags, they just weld a piece of square tube to the mag body to fill the magwell on the lower....

Simply cut the tubing off, "BAM" ---- 1 Uzi or Sten mag that fits right back into the original intended gun.

The only lower that is known to "fit" a GG mag is the new Mk II Cav-15 lowers.  But no one makes a mag well adapter for a 45 upper.... it's a new area....  The only 45 upper is Oly right now...  Well, aside from Kurt, but that's not "mass manufacture" (Sorry.)  


One can make a Colt style block and notch the GG mag.  I did that w/ Sten mags to use on the Colt style ASA 9mm upper.  I just notched the Sten mag.  Works great.

Many have asked Kurt to develop a lower than uses unmodified grease gun magazines.

SOCOM manufacturing did something in the past with sten mags to use 45acp.  I think they removed a little of the metal from the front of the sten mag to facilitate feeding of 45acp.  I don't now how well in works though.  I'm currenting welding up some sten mags to put 9mm capacity to approx. 55rds.  I don't know if they would work with the 45 application.  And I think capacity would be limited to 26-28rds.

Hey, don't forget Thompson mags...somehow Tim LaFrance can fit Thompson mags in a stock M16 receiver.  He only makes them for LEO and his work is incredible.  Someone now carries a semi-auto version of his work and it takes Thompson mags with no modifications to the mags.  I don't know how he does it...but he figured it out!

Last I checked, the lower is not a "stock" AR/M16 lower.  It is a dedicated lower for the Tommy gun stick mag.  YOu can't pull the 45 upper off and put a 223 upper on it.  It's just a 45 ACP rifle that looks like an "AR" that uses Tommy gun mags.

If I am wrong, I will be corrected by someone, but last I saw, that thing is made only take Tommy gun stick mags.  That's it.

Here is some info on the M16K-45 Semi-Auto Rifle made by Tim LaFrance.

[url=http://www.nait.com/m161.html]M16K-45 Semi-Auto Rifle[/url]