Anyone ever build one of these?    Not much in the way of ammo or parts.    Just interested in thoughts.
https://www.theballisticassistant.com/338-spectre/

I have had three of them, currently have a 10.5" AR and 17.5" bolt action. You're in luck, the smith who has probably been chambering Spectre's longer than anyone else is in your state. Not sure how far you are from Kershaw, but Paladin Machine was the original barrel maker for Teppo Jutsu and he's still cutting them to this day. I picked one up from him last weekend, he's got what's left of the blank waiting for someone else that wants to have one cut. If you don't reload then Southern Ballistic Research is about your best bet for ammo. Keep digging, it's a fun little round.

I built one 10 yeas ago. Everything in the post above me is 100% accurate. Maker Bullets makes expanding 300gr projectiles if you reload. My boys have dropped many deer growing up with the Spectre.

Its one of my favorites (I think I'm up to 4). We've even developed some deep hollow point copper solids that get really good results from.

I wrote most of the text for SBR Ammo's product descriptions, etc.

When I wrote that one, I got VERY interested in the cartridge, which does not happen often.

I keep vowing to build one, but other shit keeps getting in the way.

I have an 8.5” and it’s a great round.  I think of it as being what the .300 BO wants to be when it grows up.  160 gr. supers to 300 gr. subs, it’s one heck of a little round.  Brass is formed easily with one trip of 10mm magnum (not 10mm auto) brass through a sizing die then trim and load.  It also uses a standard 9mm pistol can if you want to shoot suppressed.
It uses a 6.8 bolt and 6.8 mags.  Nothing about it is hard to source.  If you form your brass from 6.8 brass, then there is a quite a bit of work to do and IIRC I had to inside neck ream the brass when using 6.8.  But the 6.8 bolt is perfect for that.  If you use the much easier to prep 10mm magnum brass, you may need to slightly, and I MEAN SLIGHTLY dehorn the tips of the extractor.  If you don't it may dig into the brass rim and not want to turn loose of the case as it is being ejected.  I used a he who is not allowed to be mentioned Super Bolt in 6.8 on mine and the very tips of the extractor horns needed to be buffed down very slightly, just removing the sharp tips.  The only reason to use 6.8 brass is if you want to up the pressures to abut 54K psi by using 6.8 SPC brass., which is useful if you are trying to push 160 gr. TTSX or 165 gr. Maker REX bullets as fast as you can push them.  If using the 10mm magnum brass and LPM primers, IIRC you need to keep pressures in the 36K or so psi range.  There is a bit of information on the .458 SOCOM forums about the Spectre.

Here is a nice little video of what a 300 gr. bullet does to a steel plate at 65 yards, suppressed.  Very quiet.

I live in Florence SC.    Lancaster is not really that far away from me.    I will look into it now.

Paladin is in Kershaw, on Gates Ford Road.  His contact information is on his web site, here. and he really only has his contact info on the site.  I have no idea how far that is from Lancaster.  Also, keep in mind you want a 1:6.5 twist or there abouts.  Those long 300 gr. subs need a bit of spin to make sure they stay stable out to 300 yards and beyond.

Do you need adjustable gas block if running subs through a 9mm or 30 cal. can?    Will be an SBR, 8.5 to 10.5 inches.

I don't shoot suppressed but I do shoot the 160 gr. TTSX supers to 300 gr. subs and I do not use an adjustable gas block.  Maybe it might be over gassed if used with a can but I honestly don't know.  Marty never mentioned using an adjustable gas block to me though, ever.

I don't think it would be a very good idea to shoot them through a .30 caliber can though.  It might be a little snug throwing a .338 bullet through a can designed to be used with .308 bullets, unless the hole in the can is a lot bigger than I imagine it is.

Seen 338 Razorback?  Basically, the same thing is 338 Spectre but using the ubiquitous 10mm Auto brass instead of 10mm Magnum.  I saw a bit on it a while back and several of the gun youtubers were testing it.  Haven't followed up on it as I have a few other calibers/firearms in the mix before going down that rabbit hole.  Ron Williams developed it and he calls it a "nano sonic" round.  I emailed him back then about possible other nano sonic offerings in different calibers and, although he didn't go into specifics, he said "stay tuned".

Either way, if you're liking the idea of a big bullets out of small cases, the RB is another offering that might give a slight advantage to reloaders (probably find a lot more 10mmm auto brass laying around at the range than 10mm magnum).

Just my observations and that means nothing, but I pick up quite a bit of brass for recycling.  I cannot recall the last time I picked up any 10mm auto brass, and besides that, wildcatting with brass from unknown origin is not, IMO, a good idea.

I am not knocking the .338 RB, but I don't get it, not when the Spectre exists.  The Spectre offers more powder space for super sonic loads and just enough powder space to get 300 gr. SMKs to the subsonic/supersonic threshold and still be within the 2.3 inch maximum COAL for 6.8 PRI magazines.  I just don't see the advantage of the .338 RB except for the price of the brass ($.08 more per case for the 10mm Magnum brass), and if that is that much of a concern, why is one wildcatting anyway?  NOBODY wildcats to save money.  Never have, never will.
The RB is like my .338 GRRR, which is a longer versions of the .338 Spectre, taking the case as long as I can for all the powder room and speed I can get with Maker 165 gr. REX  adn 160 gr. TTSX bullets.  Totally a useless round though, other than a way to burn money.  It did/does that very well!

I had my 338 spetre out a few weeks ago. I've killed many hogs with it.
10.5" barrel on an LWRC Six8 receiver set.
Still waiting on my SBR stamp.

It makes sense if you were starting from scratch and planned to only shoot subs even then it's not a huge step up just a tiny bit more optimized case size which in the real world probably means nothing. I agree with everything else.

Honestly if I were going to build a 338 Spectre right now I'd just order proper headstamped brass from SBR. Costs a little more but then you don't have to mess with anything and everyone says that if you are shooting subs the brass basically lasts forever. https://www.sbrammunition.com/338-Spectre_c_49.html

Not just with subs.  I shoot both supers and subs and have not retired a case yet.  God only knows how many times they’ve been loaded.  The Spectre and the SOCOM rounds are like the EverReady bunny, they just keep on going, and going, and going…

I agree Big-Bore, just tossing it out that there are options in these small case big bullet type rounds.  The RB is certainly geared mostly for subsonic, but I think that was the purpose anyway.  I hiope Ron comes out with more of his creations.  Would be interesting to see what he comes up with.

Another I've seen is the 458 SOCOM case topped with a monster 570 grain LeHigh controlled fracturing bullet (Josh & Holly Outdoors shoots it and tests it a lot on his you tube channel). Unfortunately, it's not quite short enough to fit the AR-15 platform, but it's a beast, even at subsonic speeds.

Need more info on the bolt action.

If you're familiar with Full Lead Taco on YT you can find some more info about it. I copied his because we were having his new AR barrel cut at the time.
Mossberg MVP in 223, Paladin opened up the bolt face and cut the barrel. Easiest to do when you have a local machinist or an FFL you can ship to, Paladin hasn't been an FFL for years now.

I posted more detail over on the 458socomforums, not sure if non-members can view posts but anyone interested in Spectre or Socom should be registered there regardless. https://458socomforums.com/index.php?topic=4606.0

I intended to do videos on it but that's about the time YT went anti 2A and I just lost all interest in doing videos.

I have a 16.1" barreled bolt action that I bought off Snipers Hide a decade ago. I had issues with the brass falling off the bolt face during extraction, but a local smith bushed the bolt and it's been great since.

I had PTG open up the receiver and stock to allow use of AR mags. I was hoping to be able to use a 6.8SPC AR mag like in a semi auto, but it's never been reliable feeding from both sides of the mag and I haven't cared enough to tinker with it anymore. I just leave a ten-round mag in the mag well and single feed rounds into the action.

300gr SMKs are a hoot at 200yds with a can on the end. Pfftt.....tink!

I was recently looking into building one as well. Can’t seem to find a pistol gassed barrel in stock anywhere. I’d get the 16” at SBR, but it’s carbine gassed. How short could I cut the carbine barrel down and still have it function with subs?

May get a 26” blank from McGowan and a reamer from 4D and make a pair of 12” barrels. My son and I could be twinsies! Hah!

Contact Thomas at Paladin Machine Shop.  He has built hundreds of .338 Spectres in all barrel lengths when he was doing barrels for Teppo Jutsu, the originator of the .338 Spectre.  Tp555(at)vfemail.net.  If anyone can answer your question, it’s him.

My 8.5” .338 S is pistol gassed, obviously, and has never missed a beat.  It uses an ARP 6.8 Super Bolt with the extractor’s horns rounded off a bit so they are not so pointed/sharp.

Why are you so hung up on pistol gas?  The .338 Spectre is not the same animal as the .300 BO.  SBR took over Teppo Jutsu’s business when Marty closed down operations when he left the country.  If SBR lists it with CAR gas it’s because that is the gas length that works best.  Don’t confuse the .338S with the .300 BO.