I have been slowly getting together parts to build a 9mm colt pattern AR15.  Then the other day just for the hell of it i tried stuffing some .45 ammo in my STEN mags.  16 fit easy, and 17 with the follower bottomed out and the last round in the witness hole.  i havne't bought a barrel yet, and was thinking of having a custom .45 barrel made.  then have a machinist open the bolt face up to fit the .45 rim.  the only problem i see is getting the extractor to fit/work.  has anyone done this or thought of doing it?  what you do guys think, should i give up on the 9mm and go .45?

Well, let me make a few observations/assumptions....

IF your 45 ACP rounds fit, you must have used hollow points or a flat point bullet.  Normal "ball" is too long and will not fit.  To fit in an unmodified Sten, I tried Winchester ammo (flat point FMJ).

The only person I know that did a Colt pattern 45 ACP upper (or is working on one) is Kurt of Kurt's Kustom.  He has his own area in the Industry section.  Last I knew, he was tinkering w/ one.  So far, he is the only Colt pattern 45 upper I know of.  You might want to email/contact him if he is making the Colt pattern 45 upper or still in RnD.


I have  ASA 9mm set up.  I'm hoping that soon, a Colt pattern 45 will show to the market since the Cav Arms Mk II lowers (which can use grease gun mags) is about to enter the market.  But no one has made one commercially yet (Kurt would be considered a custom, I think).

I'm currently gathering parts to get a 357 Sig upper together.  Kurt has made them in Colt pattern and the round will fit in Sten mags.  He can open a 9mm bolt up to taket the 40/357 Sig rim and re-chamber a 9mm barrel to 357 Sig.

If flat point or hollow point .45 would work in a sten mag, then in theory an Olyarms .45 upper + SOCOM mag block+ sten mags = .45 cal subgun w/cheap, available mags(?)

Sounds like an interesting experiment- anyone own a .45 upper and a socom block who could try this out???

I did indeed use hollow points to check fit in the STEN mags.  just some winchester black talons i had, fed great by hand.  i also just tried some frangible ammo i had(with the plastic BB to simulate ball)it bound in the mag.  then i mic'd it and that stuff is way long.  i shot all of my standard ball ammo and haven't gotten around to buying anymore yet.  i'll try ball when i get some more.  i have a feeling that ball will work if loaded to Min.O.L.  

I think someone did.  I was chatting w/somone who said they bought a used upper (Oly 45) and it came w/ a Socom block and a Sten mag that was modified (lips widened and the front of the trimmed a bit).  But they could only use hollow points or flat points.

I have a Oly 45 upper & a socom mag block.I have 30 sten mags that I cut the feed lips open on & they work great.They only hold 16 rds & I have to use 200 gr round nose flat point lead bullets.I reload so that ain`t no problem.I bought the mags from CDNN for $4.95 ea which is a Hell of a lot cheeper than $65.00 for modified UZI mags.Only problem is the mags are hard to load.


TRY IT YOU WILL LIKE IT !!!!!!!

Does Oly make a conversion block for 1911 mags?  You can get those 15 rounders at cheaper than dirt for about $19 each (I have seen them a little cheaper too) which would be interesting- you could use winchester white box or CCI blazer on the cheap, which might make up for the magazine cost difference.  That and they are more available than the uzi .41 or .45 mags.

Will uzi 9mm mags load the 200 gr flat points?

Kurt's Kustom Firearms has a thread on their website concerning the modification of a lower recevier to accept tommy gun mags.  pparently you have to remove about 1/3 of the wall thickness from both sides to fit a tommy mag, and Kurt had reservations about compromising the integrity, but at least one was modified in this manner.  Cavalry Arms also has a lower that is wide enough to accept greasegun mags, but no mag block exists yet to actually hold it in...