243 WSSM AR15 DTech

[treillw]

Very close to ordering a 243 WSSM AR15 upper from Dtech. I've been looking at them for quite some time, but never pulled the trigger. Something about them is just very appealing to me. Shooting 87 grain bullets 3500 fps and 103 grainers at 300 fps from an AR15 just sounds so fun. Going over 4000 fps with lighter projectiles is crazy. I've looked at the 6 ARC and 6.5 Grendel, but they can't touch the WSSM - it just doesn't excite me as much. I can't believe it hasn't caught on more - probably because the mainstream wants something that factory ammo works for.

I would like to use it for deer, antelope, coyotes, wolves, etc. I think it would also be a great starter gun for a young kid, since you can collapse the stock.

I know brass is hard to find - actually it was the only brass that was actually in stock at my local sporting goods store recently, because nobody shoots it. I know that reloading for it can be a pain, but I'm willing to put in the work to find a good load for it as long as it's possible to get it to shoot. DTech offers a lot of reloading guidance and I can't imagine it will be that bad. Hopefully getting it under MOA is doable and I'd be tickled at half minute. I know that there are feeding issues with this cartridge, but it sounds like DTech has found a setup that works.

Any advice from those of you who have gone this route? What challenges did you have? Would you do it again? What would you do instead?

I'm thinking of getting DTech to build me a lower to go along with it - Magpul PRS Light Stock, Ergo Deluxe Tactical Grip, Geissle Hi-Speed National Match Trigger, Aero M4E1. Not sure if I'm sold on the Aero - any other suggestions? Other suggestions overall?

Will probably throw my TBAC 9" Ultra 30 cal can on it as well.

Thanks!

 

[TonyTheTiger]

I can't believe it hasn't caught on more - probably because the mainstream wants something that factory ammo works for.

I haven't looked at the DTech website in a while but I'd guess there's more to it than that. Does it use standard and widely available parts or is it all proprietary and only available from one source? Same question with mags? Ammo is obviously a big one. It's relatively untested compared to 5.56 or really any factory supported chambering. What is reliability and parts life like? It could be great but if no one can definitively answer that then it's an unknown and we should assume it's terrible by default till proven otherwise.
So at the end it has ballistic performance going for it and a large list of negatives or at least unknowns in the cons category.
Considering that most semi auto shooters just want them to work and use common ammo, ballistics isn't enough to tempt many people that far away from the path of least resistance.

 

[db2000]

Here’s some brass available.

243 WSSM brass (Winchester, QTY 50) | Duck Creek Sporting Goods

50 per bag of factory new Winchester unprimed 243 WSSM (243 Winchester Super Short Magnum) brass rifle cartridge cases. RELOADING PREPARATION: Brass case mouths…

www.duckcreeksportinggoods.com

 

[LRRPF52]

I’ve been intrigued with the WSSM AR-15s for over 20 years now. Olympic Arms started chambering AR-15s in it and worked on their own 30 OSSM cartridge, promising .30-06 performance from the AR-15 back in 2002-2003 timeframe.

D-Tech bought uppers, BCGs, mags, and barrel extensions from Olympic if I understand correctly to build-up with his approach to barrel finishing and overall quality rifle assembly. He eventually had to make his own mags because the ones from Olympic Arms were hit and miss at best.

The WSSM cartridge line absolutely offers the most performance from within the AR-15 receiver set. Propellant mass simply is greater than any other cartridge you can fit in here.

The peculiarity really is that a WSSM-capable AR-15 doesn’t use an AR-15 upper, bolt, or barrel extension. From an engineering standpoint looking at chamber, bore volume, port pressure, bolt mass/carrier mass ratio, magazine stack/spring rate, feeding, and managing the cyclic rate, it’s a different rifle.

The upper receiver has a much larger diameter for the barrel extension tunnel, for starters. Look at the bolt above. It’s huge, with an even larger bolt face than an AR-10. WSSM case head diameter is .535”, whereas .308 Win is .473":

The real constraint that makes me hesitate is the allowable COL hard wall within the AR-15 lower receiver and magazines, which then affects the upper receiver length as well. This case family would really benefit from its own dedicated receiver set that would allow up to 2.500” COL.

That would blow open the opportunities for bore diameters ranging from the existing line. (6.5mm, .277", 7mm, .308", .338”, etc.).

With the 2.260” COL constraint, you’re really handicapped from exploring the potential of that WSSM case even within the .243 WSSM, which has load data that contains data as long as 2.360” maximum COL per SAAMI.

But yeah, I’ve been wanting one for many years. The COL just makes me pause, but most people who hunt with it are DRT’ing elk and whatever game they point it at without issue. The larger bore diameters than .243” are what excite me personally.

That case capacity can really do whatever you want it to do once you step into some of the bigger projectile diameters. A buddy of mine made and competed with his 7mm wildcat based off it, shooting 195gr Berger EOLs in PRS, placed Nationally in top 100 for a season of hitting match-after-match (bolt guns of course). He made the cartridge for ROs so there is no doubt when that 195gr 7mm turns the hanging plates into spinners. He would tell the ROs, “If I miss, we will know for sure. But when it hits, there will be zero doubts."

Feels like shooting a 7mm-08 to me. .270 would be cool too, especially with all the new bullets that have been developed for the new line of cartridges. 6.5mm goes without saying.

 

[SWgeezer]

I have an upper, ammo, brass, dies, magazines that I would sell. The upper I have has the integrated muzzle break and I think a 22" Shilen barrel. It is the real deal, it is high maintenance and because the barrel is a 1/12 twist, it is limited to lighter bullets. I think 80 somethings will stabilize, I don't recall for sure. The reason it sits in the gun cabinet is I prefer to shoot with suppressors. I think it could be cut and threaded, not for sure.

There was a guy who could modify magazines but his name escapes me. I know Olympic Arms had the patents on all the proprietary stuff and Mike was paying for that. The reloading issue isn't that big of a deal, best advice is to buy the tool that I can't recall what the name of it is, I drop a case in it and if it fits it will chamber, if it doesn't tighten down the resizing die and cam the press over and hold it. I tried annealing some cases and it is pretty much the same deal.

One of the older Dtech uppers will flat out surprise you with how they shoot, Mike had that down to a science.

Now, what I have heard is that Mike is retired and someone else is working the machine shop. Delivery time is sketchy due to supposedly shortage of high quality barrels. Count on about a year from what I was told. I got this info from a man who was wanting to buy my kit but couldn't commit to sending funds by mail etc.

 

[LRRPF52]

When you say it is high maintenance, what are you referring to?

 

[SWgeezer]

carbon buildup, not unusual on a cartridge that has overbore capacity on powder. Not a big deal really, most people though will never clean a barrel through the ownership period on a gun. Recommend cleaning at about 50 rounds is best. Keep the bolt and carrier cleaned and lubed.

 

[LRRPF52]

carbon buildup, not unusual on a cartridge that has overbore capacity on powder. Not a big deal really, most people though will never clean a barrel through the ownership period on a gun. Recommend cleaning at about 50 rounds is best. Keep the bolt and carrier cleaned and lubed.

In a gasser with that case capacity, at least for the bullets I would shoot, I would be using an ELGS, not RLGS. I think RLGS might make sense for the COL-limited shorter bullets along with the 12” twist for .243”, but I also think you could use an ELGS with those due to bore volume relative to case capacity.

WSSM has more case capacity than .308 and any of its variations, including the .243 Winchester.

One interesting thing is that the .243 WSSM load data I’ve seen keeps it limited to 2.260”, even though SAAMI appears to be 2.360”.

.25 WSSM load data shows a lot of 2.350” COLs.

 

[treillw]

In a gasser with that case capacity, at least for the bullets I would shoot, I would be using an ELGS, not RLGS. I think RLGS might make sense for the COL-limited shorter bullets along with the 12” twist for .243”, but I also think you could use an ELGS with those due to bore volume relative to case capacity.

WSSM has more case capacity than .308 and any of its variations, including the .243 Winchester.

One interesting thing is that the .243 WSSM load data I’ve seen keeps it limited to 2.260”, even though SAAMI appears to be 2.360”.

.25 WSSM load data shows a lot of 2.350” COLs.

What's the difference between ELGS and ELGS/ what is it?

 

[Biggie1976]

Interesting thread

 

[blksno]

Just about everything in this video is cringe worthy now...but I did make it nearly 12 years ago and just about everything gun related that's that old is hard to watch haha.

The WSSM doesn't really have any feeding issues in the AR, when it's built by the right person. There are some tweaks you can do to make it better, and I used to do mods for a lot of guys back int he day. I got out of it, around the time that brass went dark for about 3 years, but now that it's available again...I've thought about doing another one.

I was shooting 105 Amax at the time. 3105 fps from modified Pmags that would hold 11 rounds seated, and feeding from an OAL of 2.400". Untouchable in the AR platform. 105 VLDs (this was before 105 hybrids existed) were too long to run in mags without having the ogive inside the case mouth.

My first one was a 24" and 9 twist, and my 2nd was a 22" and 8 twist. Both suppressed, with an adjustable gas block.
I ran 75gr Vmax for coyotes, and 105 Amax for deer, antelope.

Again, don't judge the videos...it was 12 years ago haha.


Antelope hunt


6pack coyote hunt. 30 below, feeding flawless


steel at 400


Here's some of the mods I did to make the system better than good. Not required, but it will let you do what others will not be able to do.

 

[SWgeezer]

Just about everything in this video is cringe worthy now...but I did make it nearly 12 years ago and just about everything gun related that's that old is hard to watch haha.

The WSSM doesn't really have any feeding issues in the AR, when it's built by the right person. There are some tweaks you can do to make it better, and I used to do mods for a lot of guys back int he day. I got out of it, around the time that brass went dark for about 3 years, but now that it's available again...I've thought about doing another one.

I was shooting 105 Amax at the time. 3105 fps from modified Pmags that would hold 11 rounds seated, and feeding from an OAL of 2.400". Untouchable in the AR platform. 105 VLDs (this was before 105 hybrids existed) were too long to run in mags without having the ogive inside the case mouth.

My first one was a 24" and 9 twist, and my 2nd was a 22" and 8 twist. Both suppressed, with an adjustable gas block.
I ran 75gr Vmax for coyotes, and 105 Amax for deer, antelope.

Again, don't judge the videos...it was 12 years ago haha.


Antelope hunt


6pack coyote hunt. 30 below, feeding flawless


steel at 400


Here's some of the mods I did to make the system better than good. Not required, but it will let you do what others will not be able to do.

Glad to see you are still around, I couldn't recall your name or from Predator Masters. Are you still shooting it? Were you shooting the 75 vmax through a 1:12 twist? About the only thing that is comparable is the 22 creed.

 

[blksno]

Glad to see you are still around, I couldn't recall your name or from Predator Masters. Are you still shooting it? Were you shooting the 75 vmax through a 1:12 twist? About the only thing that is comparable is the 22 creed.

Nope, sold it a few years back but I've been thinking about doing it again. Was a wicked blaster 12 years ago FOR SURE.
I think my first barrel was a 24" 10 twist. Started with 75 vmax...but ended up settling on 105 amax and 95 VLDs

I'm more interested in shorty guns these days and I think an 18" WSSM is just to hard on barrels to really be worth it...but if I was gonna do it, I'd probably do a +2" gas system, adjustable gas block and I'd look at either a captured recoil spring system or a carbine system with an H3 (or heavier) so it doesn't run so aggressive.

 

[LRRPF52]

What's the difference between ELGS and ELGS/ what is it?

PLGS= Pistol Length Gas
CLGS= Carbine Length Gas
MLGS=Mid Length Gas
ILGS = Intermediate Length Gas
RLGS= Rifle Length Gas
ELGS= Extended Length Gas (often a +2” gas system length over a rifle)

 

[LRRPF52]

Just about everything in this video is cringe worthy now...but I did make it nearly 12 years ago and just about everything gun related that's that old is hard to watch haha.

The WSSM doesn't really have any feeding issues in the AR, when it's built by the right person. There are some tweaks you can do to make it better, and I used to do mods for a lot of guys back int he day. I got out of it, around the time that brass went dark for about 3 years, but now that it's available again...I've thought about doing another one.

I was shooting 105 Amax at the time. 3105 fps from modified Pmags that would hold 11 rounds seated, and feeding from an OAL of 2.400". Untouchable in the AR platform. 105 VLDs (this was before 105 hybrids existed) were too long to run in mags without having the ogive inside the case mouth.

My first one was a 24" and 9 twist, and my 2nd was a 22" and 8 twist. Both suppressed, with an adjustable gas block.
I ran 75gr Vmax for coyotes, and 105 Amax for deer, antelope.

Again, don't judge the videos...it was 12 years ago haha.


Antelope hunt


6pack coyote hunt. 30 below, feeding flawless


steel at 400


Here's some of the mods I did to make the system better than good. Not required, but it will let you do what others will not be able to do.

Nothing cringeworthy about those. They’re still great to watch in 2022, with a lot of great content.

 

[SWgeezer]

Nope, sold it a few years back but I've been thinking about doing it again. Was a wicked blaster 12 years ago FOR SURE.
I think my first barrel was a 24" 10 twist. Started with 75 vmax...but ended up settling on 105 amax and 95 VLDs

I'm more interested in shorty guns these days and I think an 18" WSSM is just to hard on barrels to really be worth it...but if I was gonna do it, I'd probably do a +2" gas system, adjustable gas block and I'd look at either a captured recoil spring system or a carbine system with an H3 (or heavier) so it doesn't run so aggressive.

Mine is a stock DTech 22" 12 twist with the internal compensator, I do run JP recoil system on it, With 55 to 70 grain bullets, coyotes just lay down out of respect. LOL. The only issue I have ever had was a separated barrel extension, If you look at one, they are really thin. Mike Milli replaced it and just shrugged his shoulders and that the bore looked fine, he thinks they should run for around 2,000 rounds if you don't do mag dumps.

 

[blksno]

Mine is a stock DTech 22" 12 twist with the internal compensator, I do run JP recoil system on it, With 55 to 70 grain bullets, coyotes just lay down out of respect. LOL. The only issue I have ever had was a separated barrel extension, If you look at one, they are really thin. Mike Milli replaced it and just shrugged his shoulders and that the bore looked fine, he thinks they should run for around 2,000 rounds if you don't do mag dumps.

I did have a bolt lug break, but this was after testing a LOT of over pressure loads to see where the failure point was. New bolt, good as new.

 

[SWgeezer]

If they were introduced today, the 243wssm in AR 15 would be the rage, back then everyone cringed over a barrel replacement, now days it is no big deal.

 

[blksno]

If they were introduced today, the 243wssm in AR 15 would be the rage, back then everyone cringed over a barrel replacement, now days it is no big deal.

I'm not aware of anyone doing a +2" gas system back in 2009 when i built it either.

 

[treillw]

What barrel twist would you recommend?

I'd like to shoot the biggest bullets I can for deer and something going 4500 fps would be awesome for coyotes.

 

[blksno]

9-10 is fine...but I always prefer the 8.
You're not going to be able to shoot the ultra high BC bullets (109 Hybrid, 110 Atip, 115 Dtac) just simply due to mag length restrictions.
100-105gr is going to be where you top out for deer which is plenty.

Now, you will be able to bump that up with a 25wssm but that's another topic.

Forget thinking about 4500fps on coyotes. Stick around 37-3800 and be happy.

 

[SWgeezer]

What barrel twist would you recommend?

I'd like to shoot the biggest bullets I can for deer and something going 4500 fps would be awesome for coyotes.

55 grain factory is only around 4,050 and that is about max for real.

 

[treillw]

I'd also like to get a 5.56 upper to go on the same lower for a rainy day.

I intend to keep the lower as lightweight as possible because I'll hike hundreds of miles with it hunting.

What's the best route for a defensive 5.56 upper? Get d tech to build one? Noveske/Daniel Defense upper?

Thanks!

 

[SWgeezer]

anything custom built is probably over a year out

 

[LRRPF52]

If they were introduced today, the 243wssm in AR 15 would be the rage, back then everyone cringed over a barrel replacement, now days it is no big deal.

You need a whole new upper, with unique barrel extension diameter, different bolt, and magazines. That’s a lot different than a drop-in solution for the home-builder.

Brass web diameter is .555” for reference. Thread relief cut is the failure node place to watch for chamber stretch in that direction using the legacy barrel extension and thread tenon approach from the AR-15. I would prefer to see the WOA competition extension approach to threading on the WSSM for this reason, and even a larger extension diameter than an AR-10’s. There’s a lot of bolt thrust from the WSSM cartridge line, as they are SAAMI rated to 65,000psi MAP and true magnums.


Here are some pics they have in the gallery from sectioned pressure-containment parts after destructive testing:

 

[Hayden Stone]

Is D tech still making these? I’ve left him a voicemail and a few years ago we spoke on the phone. I shot 243 wssm in the early years as a young hunter and the round has never left me down. Been shooting AR-10 308 now for a while and looking to get into my old favorite round. Good reads.

 

[blksno]

Is D tech still making these? I’ve left him a voicemail and a few years ago we spoke on the phone. I shot 243 wssm in the early years as a young hunter and the round has never left me down. Been shooting AR-10 308 now for a while and looking to get into my old favorite round. Good reads.

My understanding is he retired and handed the reigns off to someone else, don't know anything more than that. I did find someone else selling new brass again and thought about getting back into it. Of all the guns I wanted to do again, this is the easiest to step back from.

 

[SWgeezer]

I still have mine, years ago I had a barrel extension separation, he fixed it no charge, Mike Milli is retired but still involved. He has always been hard to make contact with. Follow the instructions on the website.