AR15 question...
I have a Olympic AR chambered for .45acp. I also have a spare upper in 7.62x39mm. I want to be able to change them out with ease, but the 7.62x39 upper uses a stronger hammer spring, requiring more breakdown time than desired for the swap. If I were to put the stronger hammer spring in the Oly lower for the 7.62x39, would I be able to use te .45 upper with it?? Or will the firing pin on the .45 bolt assy take too much punishment?? OR should I just get a stronger firing pin for the .45 bolt assy?? OR do I really even need the stronger hammer spring for the 7.62x39?? Any advice or knowledge/experience would be great. Thanks much!![;)]
EDIT: The Olympic .45 uses modified Uzi magazines, so there is no need for a magwell spacer. My only issue is with the hammer spring.
And one more question: If the 7.62x39 spring IS too strong for the .45 ammo, is there any way to modify the firing pin?? I.e. Shorten it a couple thousandths?? Either way I am going to the range this weekend to do some experimenting. Any more thoughts are welcome. Thanks agan!!
EDIT PT. 2: While I appreciate the discussion, my concern is not with the change of magazines. My Oly lower is not modified with a mag well adapter or anyhting else. It is not an original Oly .45ACP, but a Oly MFR .223 lower with an Oly .45 upper. I built this gun. So, that said, I am looking for info/experiences with the hammer spring problem. I'm leaning more towards trying the light spring with the 7.62x39 ammo and seeing what happens. The majority of the ammo I have in that caliber is Cheetah. It is pretty good stuff and I'm hoping the light spring will do the trick. If there is anyone else who has had this delema or heard of a viable solution, I am all ears. So, again to be clear, it is a spring issue, NOT a magazine/magwell issue. Thanks again.
EDIT: The Olympic .45 uses modified Uzi magazines, so there is no need for a magwell spacer. My only issue is with the hammer spring.
And one more question: If the 7.62x39 spring IS too strong for the .45 ammo, is there any way to modify the firing pin?? I.e. Shorten it a couple thousandths?? Either way I am going to the range this weekend to do some experimenting. Any more thoughts are welcome. Thanks agan!!
EDIT PT. 2: While I appreciate the discussion, my concern is not with the change of magazines. My Oly lower is not modified with a mag well adapter or anyhting else. It is not an original Oly .45ACP, but a Oly MFR .223 lower with an Oly .45 upper. I built this gun. So, that said, I am looking for info/experiences with the hammer spring problem. I'm leaning more towards trying the light spring with the 7.62x39 ammo and seeing what happens. The majority of the ammo I have in that caliber is Cheetah. It is pretty good stuff and I'm hoping the light spring will do the trick. If there is anyone else who has had this delema or heard of a viable solution, I am all ears. So, again to be clear, it is a spring issue, NOT a magazine/magwell issue. Thanks again.
0
-
I don't know of a reliable way around your dilemma.
Rifle primers are thicker to accept higher pressures. Needs appropriate spring.
Pistol primers are thinner to accept the lighter blow that a pistols hammer, or striker will impart.
Heavier spring striking the pistol primer may cause 'primer through-strike', known as primer puncture.
Lighter spring striking the rifle primer will lead to misfires due to light primer strike.
Best, Joe0 -
You might get by with the lighter spring using domestic 7.62 ammo but would likely get fail-to-fires with the hard primed foreign ammo. Even this is a question mark as my 5.45 upper came with a stronger hammer which I didn't install and it works fine. 0 -
I have and use a bunch of ARs in everything from 9mm to 223/7.62 and 450 and using a standard RRA 2 stage have never had any ignition problems. I don't have the greatest expectations on the 7.62X39, so whatever is cheapest is what I use and that's Wolf. They go "bang" every time and no problems with the 9mm using the same. 0 -
A colt 9mm lower has a spacer pinned into the mag well so the much smaller pistol size magazine is held secure. I think the bushmaster 45 lower will have something similar.
So the bigger concern is how could you easily remove the spacer to allow you to insert a rifle size magazine??0 -
quote:Originally posted by jplookster
A colt 9mm lower has a spacer pinned into the mag well so the much smaller pistol size magazine is held secure. I think the bushmaster 45 lower will have something similar.
The OP has a OA rifle which is NOT the same as the guns you are talking about. Plus NEITHER of them come in .45 ACP
quote:
So the bigger concern is how could you easily remove the spacer to allow you to insert a rifle size magazine??
Easily. The OA 45 guns used modified Uzi mags that have the mag block welded right onto the mag. NO mods to the lower it needed.
Here is a pic of a 10rd AR45 mag made from a Uzi mag,
The 9mm OA guns use modified Sten mags that have a block welded right on to it so NO mods to the lower is needed.
Then there are the conversion blocks for 9mm guns that use either Colt mags or Uzi mags (modified or not depending on the block) or unmodified Sten mags. Then of course there is the MGI lower that will fit just about any mag as there lower comes apart and changes mag wells.
The only ones that are not "easy" to convert are the Colts or any copy that has the mag block pinned in, which is still removable by taking out the pins. There of course there is also other dedicated lowers like the OA that is machined to take Glock mags.
The "Colt" style and "OA" style 9mm parts and mags are NOT interchangeable.0
Please sign in to leave a comment.
Comments
5 comments