In my quest to be different, I have been playing with the idea of a .45 GAP upper. The advantage is, the round will fit in existing 9mm magazines and still have the same punch as a standard .45 round (at least in the 200gr bullet). This allows use of existing magwell fillers and 9mm magazines and regular AR lowers. Here are some pictures of a .45 GAP round in a Sterling mag. I managed to fit 17 rounds in the mag. I could probably get 20 or more but the curvature of the mag caused some binding at 17 rounds.

The pictures are out of focus but you can see the rounds fit easily. I can't speak for how they feed as I do not have an .45 upper yet. The mag is actually center feed although the picture makes it look like dual feed.

Let me know if I'm smoking crack here or if I'm onto something.

VERY  interesting!  What are your thoughts on this round staying in production for the long haul?

With the announcement of cavalry arms making a billet lower that will accept greasegun mags I dont see alot of utility in making the GAP setup work.   I bet you could have the barrel custom chambered for the GAP round if you really have your heart set on it.    If you're in a ban state this might be more useful in setting it up with your preban receiver though.

Quoted: With the announcement of cavalry arms making a billet lower that will accept greasegun mags I dont see alot of utility in making the GAP setup work.   I bet you could have the barrel custom chambered for the GAP round if you really have your heart set on it.    If you're in a ban state this might be more useful in setting it up with your preban receiver though.

A GAP barrel would be an alternative to those that want to stay with the Uzi mag/9mm OAL rouund.

The Cav arm could cater to those wanting to run M3 mag and full size (1.200+ OAL) 45acp and barrel chambered accordingly..

Cav Arms has given no indication when they will be ready for production and a guy can switch back and forth between 9mm and .45 GAP by swapping uppers and magazines. The M3 lower requires a whole new weapon.

Someone who has a GAP pistol can then have an AR in the same caliber. The idea is not to replace the .45 upper but compliament it with another option.

If Cav Arms ever makes it to market, I will buy one of their M3 lowers myself, but I like the idea of using existing pistol caliber parts with just a new barrel.

The real issue seems to be finding someone else willing to make .45 barrels. Having one source backordered all the time is irritating.

Good thinking man.
You're following the very purpose of 45 GAP, to fit it into 9mm sized weapons.

Quoted: VERY  interesting!  What are your thoughts on this round staying in production for the long haul?

Well, more and more guns are being chambered in it.  Also, the ammo is being manufactured by more then one major manufactuer now....

I personally wouldn't buy it....though I received some ammo by accident....didn't realize it till a few weeks later that the local gun shop guy grabbed the wrong boxes.... too late to return.

If it has the same power as a 45 ACP w/ the 200gr bullet, but in a 9mm frame, does that mean the recoil will be "worse"????  I don't really want to get started in a debate of capacity vs power vs recoil vs (what ever)....


-edit
actually, the Cav Arms CAV-15AL would take a mag block for a 9 set up (single peice).  But, if your point is that the 45 GAP would serve people w/ existing lowers, I agree.....

But it bring up an other issue why the 45 ACP uppers are not in abundace....mags.  The CAV-15AL is one way to solve that 'issue'-to use the supply of GG mags.  Another solution (mainly up to Oly), is to make mags.  Since Oly uses a spacer block, it would be in their best interest,  in my humble opinion, to get together w/ a mag manufactuer and MAKE some hicap 45 ACP mags that fit in the standard mag well.

The only thing I don't like about the Cav Arms lower is the lack of ability to customize, ie. change grips, buttstock. Making a lower thats wider at the magwell shouldn't be that hard for companies making lowers out of billet. A new forging blank would be required for manufacturers making them from forgings.

I am also experimenting with 9mm mags that might feed the .45 GAP. I was able to load 17, .45 GAP rds into a 30 rd sterling mag. The curvature of the mag was the limiting factor. I'm going to try an UZI, Sten, and some others as I aqcuire them. I can't test feeding from the mags yet but I'm working on it.

I got 14 .45 GAP rds into a 20 rd, 9mm Simunitions magazine but the plastic mag started to bulge out and it wouldn't fit in the mag well.

Quoted: The only thing I don't like about the Cav Arms lower is the lack of ability to customize, ie. change grips, buttstock. Making a lower thats wider at the magwell shouldn't be that hard for companies making lowers out of billet. A new forging blank would be required for manufacturers making them from forgings. I am also experimenting with 9mm mags that might feed the .45 GAP. I was able to load 17, .45 GAP rds into a 30 rd sterling mag. The curvature of the mag was the limiting factor. I'm going to try an UZI, Sten, and some others as I aqcuire them. I can't test feeding from the mags yet but I'm working on it. I got 14 .45 GAP rds into a 20 rd, 9mm Simunitions magazine but the plastic mag started to bulge out and it wouldn't fit in the mag well.

You mean like this?




There is your billet.....This is the Cav Arms lower I was refering to..... it's a new addition to the line, yet to be released.  Please note, the selector hole will NOT be on the "civilian" models.....(that's what they posted.)  It's called the CAV-15AL.



The 45 ACP will feed out of Sten mags when FLAT POINT bullets are loaded.  So, I would assume the GAP would work also.  I forgot how many can be loaded in a Sten, someone posted it once....

Quoted: ... in a Sterling mag. ... The mag is actually center feed although the picture makes it look like dual feed.

I thought I saw on another thread that Sterling mags are dual feed?

If .45GAP is the same length as 9mm, then Sten mags should work with it.  Isn't the problem with .45ACP magazines that they're too wide to fit in a standard AR magwell?  Won't the single-feed nature of the Sten mags solve that?  What mags does Oly use for .45ACP?

Great photo. I'll buy one as soon as they hit the streets.

If the sterling mags are double feed with 9mm, they appear to be able to work single feed with .45 GAP. The sides of the mag are straight all the way to the top so you may be right.

When I was loading the .45 GAP rounds, the top round almost always ended up right between the feed lips. The photo dosen't show it but as soon as I moved the mag around alittle, the top round would move up into the feed lip area. Voila! Single feed. Probably would take some fiddling with to make it work consistantly.

I'm still going to be tinkering with the .45 GAP idea because I like the challenge and it offers yet another option the AR owner.

FYI-

I just stuffed a normal Sten mag w/ 45 GAP and I got 17 rounds in there.  And that is using a loader to compress the spring.  So realistically, I'd say a Sten mag is a 15/16 round mag.....in 45 GAP.

In theory, the easiest way to get a 45 GAP upper would be to pick up an Oly style upper, bolt/carrier unit and have someone make a barrel.  If you go the Colt pattern, you'll have to have a 9mm bolt opened up.  Heck, if you asked, you "might" get Oly to sell you an unchambered 45 barrel...but I doublt it......


Using SNS Industries two peice mag block to use the 223 mag release, it would be a cool set up...or a SOCOM block and use the paddle.  Either way, the Sten will eat 45 GAP and the only thing one has to fiddle w/ is the lips (open up a bit).

TAG

Honestly, the only advantage I can see to a .45 GAP AR15 is if it takes pre-existing handgun mags. Particularly Glock mags given that aftermarket extensions are readily availalbe. For example consider a G37 mag with a Taylor Freelance +8 extension (+8 in 9mm that is), I'm guessing that you would get about 15rds in the thing, maybe 16 or 17. This would roughly equal the capacity of the .45ACP UZI mags and would not be horribly behind a G21 mag with an extension but would fit in any AR receiver out there without modifying the reciever itself AND you could share mags with a pistol.

Tsh77769