Home Forums Hunting & Shooting Custom Rifles & Wildcats SA 9.3?

Having played with a few... I know this to be accurate...

.375 SOCOM is identical to .358 Winchester (so identical... same powder, same powder charge, same bullet weight and only 10 FPS different.

.375 Raptor is in the same kinda way equal to 35 Whelen (Speed and energy wise). Google for better details.

The Raptor does sound pretty interesting. One question I have is do you think it will feed ok from a staggered BDL style mag box? On their website I see mention of center feed detachable mags but cant find any information on feeding from a staggered BDL style magazine set up.

I have a 375 SOCOM in an AR platform and it shoots the Wilson Combat Speer 235 grain load under 1 MOA. This is the gun I carry when I go out Predator calling for bears. I haven't had any luck but I still try every year.

I have a 35 Whelen loaded with a 200gr barnes TTSX at 2900fps. The factory Remington 1:16" twist limits this round to about 250grs. Thus the 9.3's start basically where the 35's stop with some overlap at around 250grs. It's an interesting comparison between a 375 Raptor and a 35 Whelen, but they're very different cartridges. The 375 Raptor reminds me of a scaled up 35 Remington and loaded to modern pressures, which is a very good idea. I think a 375 Raptor in a Remington760 would be another great idea.

Tony (Tromix) allowed me to buy a .375 reamer years ago (it is a patented round)... we built lots of guns (nothing he sold or was willing to make... i.e. why he let me buy the reamer).

I also did a bunch of .358W stuff (rented reamer).

Then I fell in love with 9,3m...

THEN... Chris and the boys discovered Arne's .375 Raptor... they went in big time (bought the reamer et al). Data is super impressive... like 10 on 10 @ 400 yards against 8" round steel. They pushed the data really hard and thus I made the 35 Whelen comparison.

I did not partake, because it was "between" what I already had.

As for feeding in a bolt gun... I forget the mag (ACS maybe... or maybe these guys (https://hsprecision.com/product/remington-700-detachable-magazine-conversion-kits/)... I do know it was not Magpul.

If I get a chance I will ask. He may share knowledge... no promises.

He is all in on the Zeus Terminus stuff now... OCD about it actually.

I am less complicated... 700s and AR-10s... But a Savage 99 in .375R or 93Jimbo would be a blast (doubtful).

Missed the BDL part... yes... it should feed fine... my 358Ws feed perfect (I built two)... never had a problem.

The Raptor shines because of the powder... 10x is really odd... but it shines with the Raptor.

FYI... there is some "Hot weather sensitive" cautions.

Sounds like you guys are doing some great work. The comparison of the Raptor to the Whelen is at least reasonable when bringing something unknown to light. The whole purpose of the Raptor is to deliver similar ballistics from a shorter SA platform which is a very worthwhile endeavor. I very recently picked up a 9.3x57mm Mauser and haven't had a chance to play with it yet, but the ballistics are nearly identical, but again, the Raptor does it from a SA. The option to go semiautomatic is very cool. All I can say is keep it up and keep sharing the developments here

Thank you kind Sir...

I am hopeful that the 93Jimbo (named after a GREAT FRIEND that passed last Thanksgiving) will surpass the .375 Raptor (which I highly respect... i.e. Arne is BRILLIANT).

I am hoping to proof out the Most Powerful .473 (.308 parent) cartridge ever devised. 500 yard on elk... kinda thing.

We will be making reamers and dies... I already have 2,000 bullets (Lapua and Norma)... we will use 358W Starline brass.

The reamers will be available to anyone (no surcharge) if we succeed.

Jimbo was THAT GREAT of a man... and friend.

Only if it's a straight re-bore on a 6.5CM.

If so, I just might have to join you.

That's quite the tribuite. I'll try to follow along.

That would be the easy route to a short action 9.3!

93Jimbo still in process...

I still think we need a lower shoulder and maybe 40 degree.

As it stands now... .358W brass necked out to .366 with 185 grain Lapua.

Trim at 2.000" (may shorten that... not sure yet) hits the cannelure well in the 185s.

As we do 232 gr Normas the extra neck may become critical. I hate to lose the case volume... it is a balance.

The long throat is where we will get the speed.

93Jimbo...



We will be having reamers fabricated in January...

Dedicated to James Collyer... Jimbo.

Great man... Great friend to many... passed a year ago.

Thus is born the 93Jimbo (.366 x 51)

This will be the most powerful .308 based (parent) cartridge ever devised. Builds and load development will take about 6 months... Stay tuned...

93Jimbo is going to be a real MONSTER!

This is a ZERO PROFIT project...

Any money made by accident will go to Jim's widow. Donations as well...

If successful... reamers will be available to anyone that want them at cost... BUT the 93Jimbo name cannot ever change. (i.e. no 93 Creedmoor bullchit).

Looking good! Keep us posted.

Just curious, but how would the 93Jimbo be more powerful than the 375 Raptor that is also based on the 308 case? Is the 93J somehow blown out and improved with a sharper shoulder? The ballistics of the Raptor are very impressive and would be tough to beat without any modifications to the parent case

When I was really bored I had a 375-358 checked to see if there was ample shoulder and it should work just fine. My judgement caught up with my boredom and ended the inquiry.

So the .366 will work. Whether it is worthwhile is a different issue.

Truly a labor of love and of deep respect. I can’t fathom how honored your friend would be to know that you guys have gone to such great lengths, not to mention detail and time, creating a fantastic round in his honor.

I wish you great success and I’ll be following closely since I have a AR-10 upper and lower needing something inspired….

We have slightly more case volume... We are using lighter bullets (185 Lapua) and possibly turn some others as well... better BCs

We will be using Borerider style throat geometry (think Weatherby).

Faster speeds will tweek energy upwards.

Friends are helping fill in the gaps of my ignorance (which is plenty)... i.e. kinda like the 30-06 Serengeti bore-rider concept hits .300WM levels.

Jump does not effect accuracy in medium and big bore like it does on smaller bores (based on my experiences)... we are pushing that idea VERY HARD.

I respect the question you asked... I have asked of myself just that many times.

I have huge respect for Arne and his 375 Raptor (less for the 45 Raptor... no hard feelings, but I just hate case mouth stuff personally... shoulders or belts ONLY for me)...

To repeat... the .375 Raptor is amazing (we have tons of experience with them)... Huge respect.

The 93Jimbo will hopefully be a bit more...

In a nutshell...

The long throat concept of Weatherby will marry the faster powder revelations of Arne and the innate efficiency of .366s.

In the end... .358W may also gain some ideas/data also.

I believe that the 9.3J is barking up the right tree considering the bullets that are available. Bullets for the. 375 either tend to be too soft (375 win levels), or too tough (made for the H&H). 9.3J performance splits the difference between 9.3x57mm, and 9.3x62, except fit a short action and semi A platforms thus bullets are already taylor made. The 286gr PPU projectiles are soft enough to expand on deer at x57 levels yet hold together in tougher assignments. Bullets in this diameter tend to be readily available. Not many in NA use this diameter yet most of the major manufacturers are producing components and I've seen they're the ones in stock. Go figure

Smart man recognizing the bullet construction dilemma...

As well as availability...

Had lots of poor performance with 270 grain bullets with the .375 Raptor. Zero expansion.

...and the Sierra 2900s (200s) were more of a .375 SOCOM bullet They work in the Raptor but not ideal... also kinda scarce to find reliability.

I am hopeful of the Lapua G574s in .366 (have 1k on hand to play with)

https://www.lapua.com/product/93-mm-open-tip-bullet-g574-120-g-185-gr/

and the Norma 232s (have 1k on hand to play with)

https://www.norma-ammunition.com/en...-fmj/norma-fmj-93mm-366-232gr---20693061

https://www.norma-ammunition.com/en...n/norma-vulkan-93mm-366-232gr---20693051

https://www.norma-ammunition.com/en...ryx/norma-oryx-93mm-366-232gr---20693071