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

Manson is making the reamer... if anyone wants to buy one and run parallel with us... drop me a PM. Will share data, gauges, throater, twists et al.

Otherwise... more info to follow...

ONLY ONE RULE... the name of what we do remains "93Jimbo"... That is important to me and Jim's family/widow.

there is another way to boost velocity and still have the bullet close to the rifling for accuracy

The +P stepped rifling does work to lower initial pressure spikes & allows you to work up to higher velocity as you bring the pressure up

Added a throater to the order I made yesterday for just that reason. Going to do 1:12 and 1:16 barrels as tests... start with a 28" blank and cut down as a test also. Work out the nodes kinda thing.

The .308 case, no matter how much you "improve" it does not hold enough powder to get heavy 9.3 bullets such as 286 grains, going fast enough. You are limited to about 50 grains of powder. Once you go to a decent weight 9.3 bullet, you need to go to a slower powder such as H4350, and the .308 case improved will not hold enough of the larger volumes of slow powder. If you run the improved .308 case at high pressures, the primer pockets are too loose after about 3 firings. If you run light bullets in a 9.3, they don't have enough sectional density for anything large. And the more you "improve" the .308 case, the more you stuff-up its good feeding.

So... in your opinion...

Throwing a 175 grain bullet with a poor SD at 2,900 FPS... using a fast powder such as AA 1680... is not a reasonable proposition?

There are better options. If you are interested in the larger bore sizes such as 9.3, .375 then you need a case that's big enough to drive reasonable weight projectiles in those bore sizes at a reasonable velocity. Being restricted to light projectiles because of case size means that you are also restricting the size of the game and the distances that you can shoot them at. In which case, you're better off going down in bore size and using a bullet with a better sectional density. The 9.3 built its reputation on bullets such as 286 grains and a case size that holds around 15 more grains of powder than a .308 case.

This 9.3Jimbo is similar to 9.3x57mm Mauser, which is a similar situation to the 7x57 Mauser/7mm-08 Remington. However, like you, when pushing these heavy for caliber bullets, slightly more case capacity would be nice. Like a Remington SAUM necked up?

No interest in that on this project... I am working with the standard AR-10 platform with standard SR-25 mags.

If I want to shoot a bolt gun I have plenty of them in 9,3x62m and up. Hell, I even have an AR-10 and a bolt in .458 Lott.

This is about max performance from a .366 x 51 case pushing powder burn rates and then bore-riding to mitigate excessive pressure.

We have 5 years of real world experience with the .375 Raptor which plain and simple works (i.e. 175 grain bullet with a poor SD at 2,900 FPS... using a fast powder such as AA 1680)... The 93Jimbo is a push from that platform because:

A) Lighter metric medium bullets are available...

B) We understand faster (unconventional powders) better than most... and long throating.

You really need at least the .350 Rem Mag in case capacity, although the 300 RCM case necked up or 30-06 improved case necked up should do it. The SAUM and WSM cases will also do it, but you lose magazine capacity which do don't really want to do on anything dangerous or big (because you may be paying a lot to shoot the animal) and you have to be careful of feeding issues with those two cases. The WSM cases may also be a bit too long in many short actions.

NO... You do not!!!

Read the data... understand powder burn rates...

https://www.375raptor.com/load-data/


Not even close... The 375 Raptor beats the 9,3 x 57 by 12%+ and that is before the long throating which I expect to add another 12%... then regain the BCs of a .366 over the inferior .375

Norma data on 9,3x57



.375 Raptor data

Ok..which is why I said it compares to the 7x57mm (medium action)/7mm-08 (short action) analogy..loosely. and the 7mm-08 Remington is loaded hotter than the 7x57 Mauser so it usually beats it in performance

The 9.3x57mm Mauser is loaded to very mild pressure. I think around 44,000 cup if that. So the 9.3J should be able to better it just as the 7mm-08 does the x57. I'd prefer the 286gr going 2050fps myself.. but the 232gr at a reasonable speed would be nice too..

If I can get a 350 grain .375 projectile going 2300 fps from a .308 case at normal pressures using temperature stable powders or a 286 grain 9.3 projectile travelling slightly faster from a .308 case, then I want to be the first to hunt Cape Buffalo with it.

It has never been my intention to shoot 350 grain heavies in the 93Jimbo...

Arne did in his .375 Raptor... and probably could have gotten to 2,100 FPS with long throating and a 22" barrel.



We did 270s in the Raptor and had great accuracy to 400 yards, but horrid expansion. Mostly because ALL .375 bullets are for the H&H or RUM type guns. Or the very slow .375W guns. Virtually nothing in the middle range except Sierra 2900s.

This is where the Lapua 185 .366s and the Norma 232s will theoretically shine... AND will expand at 2,900+ FPS.

I may try some 250s also and possible 286s, but not as part of the development phase.

AR-10s are not legal in Africa and a SA 9,3 would never be a caliber I would take there to hunt DG. Don't be obtuse. Reread the whole thread before commenting again.

Jimbo...

I'd say the best the 93Jimbo would do with 286gr projectiles is 2100 fps, and perhaps 2,200 fps with newer optimized powders. CFE223 might be a bit slow but worth a shot. I don't have any experience with 2000-MR, but these are the types of powders to try. IMR-8208 XBR would be good as well as Ramshot TAC and Exterminator.

Been wanting to do a 9.3x51 for a long time.

Just got off the phone with Ray at Manson 15 minutes ago...

If you want to order a reamer/throater... drop me a PM. Only rule... Name has to remain 93Jimbo...

9.3 x 51 sounds good, and most people would probably work out that it is a 9.3 on the .308 case. 93Jimbo sounds a bit....retarded.

It's clear you didn't read through the entire thread before posting.