In another thread someone mentioned that it was OK to use 45 Super ammo in a Oly arms 45 ACP upper. Anyone tried this and live to tell the tale?
I'm very interested in the possibility of using this ammo in a 45ACP Oly upper to hunt deer with. Anyone ever ask Oly about it?
Would I need a stronger buffer spring? The Oly arms upper is blowback operated..would it blow the slide into my forehead? I don't want to be the test case on this...I'd love to hear from someone who knows the deal.

mmmmm.....interesting.  

I have not heard of this, but I have heard that Oly sells a all steel buffer for use in their FA stuff.  Now, a steel buffer maybe enough to slow the bolt down.  Just wanted to mention that.

Kali, I'm not a ballistics expert or anything, we need to get some ballistics gurus in here, but imho it isn't the speed of the bolt carrier when the spring is compressed that we need to worry about, but rather the pressure spike from the chamber pressure of the cartridge as soon as it is fired.  I don't know the details on .45 Super but I believe it has a pretty good pressure spike upon firing.  Lock time of the bolt will be affected, and you have a pretty hefty bolt/bolt carrier assembly to move there.  It takes some time for the inertia to be overcome and for the bolt carrier to start moving in the blowback system--enough time for the pressure spike to split cases or worse?  What happens when you have a pressure spike, a hotter round that decreases lock time on the bolt, unlocking it quicker, but then probably takes a very similar amount of time to overcome the inertia of the full bolt carrier assembly after unlocking the action?  I don't know, but I doubt any changes made to the buffer assembly will have much bearing on this particular issue.

I get more than 1300 FPS from a 230 grain bullet with standard .45acp loads in my 16 inch Oly carbine upper.  If I hotloaded my rounds, I'd say 1500 fps with a 230 grain bullet is easily within reach.  With a lighter bullet maybe you could go even faster and be less hard on the gun, depending on the burn rate of your powder and stuff like that.  With decent shot placement and relatively short range (sub-100 yards?), maybe a +P .45acp is all you need anyway?

I wouldn't try .45 Super in there until someone who knows more about ballistics than Duke Nukem adds their opinion.

From Texas Ammunitions website. They are one of the companies loading .45 Super

Because 45 ACP automatics are generally designed to handle and function with the pressures and velocities of the currently manufactured and available standard 45 ACP ammunition, the additional pressure and velocities generated by the 45 Super® will cause malfunctions resulting from those firearms functioning beyond their designed specifications. The shooter should expect such malfunctions as: (1) failing to feed ammunition properly; (2) frequent jams; (3) pierced primers; and (4) possible failures in the structural design of the firearm. This list is not exhaustive, and other problems and dangers can and will occur.

Because firearms manufactured for the 45 ACP only and are not manufactured for the 45 Super® and its increased pressure and velocities, Texas Ammunition Company advises all customers not to use 45 Super® ammunition in any firearm that is not specifically manufactured or converted for the 45 Super® cartridge.

www.texas-ammo.com/ammun.htm

www.texas-ammo.com/45super.htm

I wouldn't risk it.  Its different with a pistol where tuning to make it function is done mainly with recoil and magazine springs and shortening firing pins. We're talking a 230gr bullet doing 1100fps (600+ ft lbs) out of a FIVE inch barrel.  Smith & Wesson even specifically told me they wont warrantee thier 625 .45acp revolver if you shoot .45 Super through it, and that gun is based on the N Frame, as in .44 Magnum size (due mainly to the fact that a .45 cal cartridge makes a thinner cylinder wall than a .44).  I dont think the odds of you having a catastrophic failure are that great, but I think it'll definetly beat the hell out of the gun.  Not having any experience with the oly pistol caliber uppers, Im assuming its blow back like the Colt, and it lacks a firing pin spring?  I wonder about the potential for things like slam fires?  Im far from an expert though.

All excellent points, and very well written.
I've emailed Don at Oly arms, if he replies I'll be sure to post it to this thread.

If OLY has 10mm carbines shouldn't .45 Super be on par with those, power and tuning wise?

Quoted: If OLY has 10mm carbines shouldn't .45 Super be on par with those, power and tuning wise?

I would think that pushing a 230gr round to 1500 fps is a little harder than pushing a 165-180 gr round to 10mm velocity. Also, keep in mind this is a blowback operated design with no firing pin spring, its inviting slamfires. A titanium firing pin may also be required.
I'm waiting on emails from Oly...will post replys.

OK, I just for off the phone with Curt or Kurt at Oly arms. He said go for it, no worries. No modifications needed.
I'm a little skeptical on it but hey, I'll give it a shot. I'm going to call Triton today and get a few boxes of ammo. I'm sure it'll beat the crap out of my upper but hey, its made to shoot!
Will post accuracy reports out to 100 yds.
If anyone lives in Hampton roads and has a Chrony I'd also post the info...Ross, you listening?

Both the Oly and Colt style pistol caliber carbines use a spring loaded firing pin.

Quoted: Both the Oly and Colt style pistol caliber carbines use a spring loaded firing pin.

Edited to add: I placed an order for 200 and 230 gr JHP 45 Super ammo yesterday. That stuff ain't cheap! Will try to post accuracy results. I'd love to chrony this stuff from an 11.5" bbl upper, too bad I don't have a chrony. Anyone care to step up to the plate?


Yuppers, that was exactly what Kurt/Curt at Oly arms told me on the phone. Good, one less thing to worry about.

Transcript of email from Oly arms:

What I've found out with that type of case is the blow back is going to be
greater therefore more powder in your face thanks Skip
Skip Fletcher
Domestic Sales Rep.
Olympic Arms Inc.
800-228-3471    Order Line
360-459-7940    General Info
360-491-3447    Fax
www.olyarms.com


----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Monday, December 30, 2002 6:22 AM
Subject: 45 Super in a Oly upper?


>   Skip,
>    I've got a question on the 45 uppers. Is it safe to use 45 Super in
them?
> If so, does Oly sell a stronger buffer spring? I'm interested in hunting
> deer with my 45 ACP upper and I could really use the extra velocity that
the
> 45 Super provides.
>
>
>
> Thanks for the info,
>   Ryan
>

Need I say more......?

LOL!  Why is it that the .45acp upper throws so much unburned powder in your face, anyway?   I'm sure it would really piss me off if I were a lefty.

If Oly says go for it, let us know what happens.  The velocity is going to be wicked!

Cool, go for it then.  You'll be getting close to .45 Win Mag.  It should be impressive.  Still recommending the XTP for hunting.

Unburt powder????  I say if one reloads, use a faster burning powder... just a thought.  Not sure what that will do w/ the presure spike though.