AR15.Com Archives
 .223WSSM and .243 WSSM AR-15 uppers?
7/23/2003 9:45:52 PM
I just saw a comparison picture of .223Rem and .223WSSM in my American Rifleman, the WSSM looks like it is a half inch shorter. Could an AR-15 upper be designed to handle the .223 or .243WSSM? Any thought/comments?
Colt_sporter  [Member]
7/23/2003 9:52:07 PM They have designed a PCR-8 mag upper in both of these calibers.
MartytW  [Member]
7/23/2003 9:52:18 PM
Olympic Arms has designed just that, and these uppers should become available this fall. They feature a custom bolt, bolt carrier, extension and upper receiver, but will interface with a standard AR-15 lower and can use standard GI mags. My only concern is with the cartridges themselves, if the 22-250 and 220 Swift are prone to throat erosion, I would think the 223 WSSM would be a prime candidate, especially operating at 65,000 psi. But back to the topic at hand, Olympic Arms is your "go to" place Marty
Troy  [Site Staff]
7/23/2003 11:26:30 PM
My concern is the high pressure coupled with a bolt-head with a very thin ring connected to the locking lugs (the case head on these cartridges is MUCH bigger than .223, and requires a lot of material removed from the bolt face). It seems like a kB! waiting to happen to me. Perhaps if it had been built on an AR10, that would be something else. These were strictly designed as bolt-rifle calibers, with no thought for the feeding and bolt-face problems in semi-autos. -Troy
MartytW  [Member]
7/24/2003 10:22:59 PM
Troy - I had the same concerns, but when I saw the prototype at SHOT, I was not as concerned. Oly made a new receiver to accomodate a new extension that uses a new bolt head - not a modified AR-15 like we do with the SOCOM - MUCH BEEFIER. Almost looks like they are using an AR-10 bolt head and extension in a modified AR-15 upper and carrier. From the looks of it, it should be OK, but then again, it was a prototype feeding dummy rounds. Feeding, btw, seemed to go without a hitch ... Marty
WSAR15  [Team Member]
7/24/2003 10:35:32 PM
Marty: Will you offer a 223 WSSM?
Ky_Bob  [Team Member]
7/24/2003 11:17:26 PM
WOW! I want a .243 WSSM AR15 so bad I can taste it. This is great news! Bob
7/25/2003 6:20:11 PM
[quote]WOW! I want a .243 WSSM AR15 so bad I can taste it. This is great news! Bob [/quote] Thats exactly what i want too.
Ky_Bob  [Team Member]
7/25/2003 8:42:12 PM
[quote]Originally Posted By DEERSNIPER: [quote]WOW! I want a .243 WSSM AR15 so bad I can taste it. This is great news! Bob [/quote] Thats exactly what i want too. [/quote] Judging by your handle, I think we have the same idea. [:)] That is going to be a flat shootin sonofabitch! Bob
sloth  [Member]
7/25/2003 10:41:20 PM
I've been lusting after one of these for months now. I have yet to get a firm number on how many rounds you can fit in a 30 round magazine. Also, if any magazine mods are needed to insure reliable feeding.
MartytW  [Member]
7/27/2003 12:43:28 AM
I/we will not be offering a WSSM upper, that is Oly's terrain ... won't tread there. Now, there is the possibility that we might want to wildcat that round, and that possibility I leave open.... Magazine capacity should be the same as the Beowulf or SOCOM. Those two are 0.54x" diameter, whereas the WSSM is 0.555" The 30 rounder should take 10 rounds, although spring pressure may suggest you keep it to 9 .... Marty
Fritze  [Member]
7/27/2003 2:46:04 PM
I was still with Oly Arms when the .223 WSSM and .243 WSSM where in prototype stage, in fact I personally ran the first bolts, carriers and extensions. All dimensions were modified for the new caliber, the bolts are much beefier and the lugs and boltface shouldnt be of any issue. In fact a WSSM bolt will never fit in an .223/5.56 carrier, its physically too large, WSSM carriers are modified to take the new bolt. WSSM extensions are modified to accept the new bolt as well, with its increased size and locking lugs. Oly spared no expense in this area, its all been overengineered to alleviate any further issues. I didnt witness any modifications to the uppers, that was done in another area of the company. It was shortly after I left that they started putting some together for R&D test firing. I cannot wait for one in .300 WSSM (or whatever Winch might call it), or .300 Olympic (or whatever they call it as well). Fritze Out.
WSAR15  [Team Member]
7/28/2003 5:26:56 PM
I asked Oly when 223WSM SUM barrels would be available and the twist. They were hesitating between 1:10 and 1:12 twist, but advised they would be available late September. I wouldn't take it to the bank, but they're getting closer.
MartytW  [Member]
7/29/2003 10:01:13 PM
I ran some numbers on the 308 version of the WSSM. While it is strictly a simulation and I had to make some assumptions regarding case volume, the numbers gave a reasonable idea of the performance. Basically, the 308 version will need to be pushed to 65K psi to achieve the performance of the .308 Winchester. Question is, can the rifle (upper) withstand pressures THAT high, repeatedly? I do not know. The WSSM versions run slightly lower pressure than that, so it might be feasible. The Holy Grail is a little closer, but not quite there yet. (At least, not according to the computer) Now, we also looked at making a 375 version, simply because the length of the case happens to perfectly match the location of the cannelure on the Barnes .375 X Spitzer. The resultant cartridge (375 WSSM) yields performance similar to the 375 Winchester. Then there are the obvious two questions: What about a 458 WSSM to rival the 458 SOCOM and a 50 WSSM to rival the 50 Beowulf? Both could be done, and both would indeed raise the bar. Looks like Olympic Arms really did their homework on this one. Hats off. This just means that us other tinkerers need to think further outside the box to raise the bar yet another notch.... Fun, fun Marty
Fritze  [Member]
7/30/2003 3:33:44 AM
[quote]Looks like Olympic Arms really did their homework on this one.[/quote] Its nice to have millions of dollars in equipment and oodles of experienced engineers at a companies disposal,lol. Fritze Out
sloth  [Member]
7/30/2003 12:07:04 PM
[quote] Now, we also looked at making a 375 version, simply because the length of the case happens to perfectly match the location of the cannelure on the Barnes .375 X Spitzer. The resultant cartridge (375 WSSM) yields performance similar to the 375 Winchester. Marty [/quote] Please keep us up to date on this...I liek the combination of big bullet with a flater trajectory that the 458 and beowulf. My thoughs were on developing a 338 whisper type load. Traditionaly based on the 7mm BR, you needed a 308 bolt to make this go...however the new oly upper makes this do-able in an ar15 platform. I'll be honest, this has not been getting much press, I think this may be the development of the YEAR. I just really think that this work by Oly is being really overlooked.
Fritze  [Member]
8/1/2003 1:50:21 AM
This kind of development wasn't as easy just a year ago for them, but now they have new cnc machines in house and manufacture their own bolts, carriers, and extentions.(Although even these new machines can hardly keep up to productions needs,lol) And they keep expanding their production facilities even now, I think two new machines are slated to be included in their production line up. I hope all the best for them. Fritze Out.
uglygun  [Member]
8/1/2003 3:52:19 PM
okay, the 243WSSM is inticing as all hell. How would the goofy thing run with long sleek VLD type rounds? Still load to mag length or not? As a varminter the 55-58grn varmint type bullets from the 243WSSM would be my primary interest for silly velocities. But then again I've got an AR10 that I am waiting to play around with, waiting to get an upper built in 260Rem geared towards the 140grn weight range of bullets. After awhile it gets hard to argue whether or not one NEEDS to have certain chamberings. I can always find a reason to want them or to want the rifles but reasonably speaking the 260Rem would probably do what I need. But the WSSM tempts me for one specific reason, I can't help but wonder how it would run compared to the PPC line of cartridges.
Zenif  [Member]
8/26/2003 5:11:17 PM
Oly has assured my that all of the tsting with the PCR-8 Mag is done, and that thay are in full production now. Rifles and uppers will begin shipping within 3-4 weeks I am told. As far as pressures, No worries. Their techie told me they fired a case loaded with 30 grains of Bullsete pistol power, and all it did was swell the chamber just a little. With the larger bolt and barrel extension combo (which i have seen, and thay are bigger and stronger than an AR10 system), they are super strong. 30 grais of bullseye in a 223 round will send a standard AR15 in 223 caliber into a million little pieces guaranteed! That barrel extension has a larger OD and the uppers are opened to accept it. they are also opened up at the ejection port for the fatter casings. These will be real fireballs, and I am really looking forward to it. Especially when Oly releases the 7mm version!