Home Forums Hunting & Shooting Ask The Gunwriters 370 Sako Magnum: Why?

Reading over the velocities listed in Bryce Towsley's excellent article on the new 370 Sako I couldn't help but think: they've produced a replica of a handloaded 9.3x62.

and in a $2500 factory rifle to boot for the advertisement I saw!

Mine runs a 250gr bullet 2700+ fps and a 286gr 2550fps, in a 22" barrel, factory duplicate load. carry one more round in the mag compared to the 375HH, sako weighs 7.25 lbs ready to go. recoil is tolerable in a lghter rifle.

Would have agreed with you till I picked one up 2nd hand for a good price. It was a Sako 85 Hunter with Optilock QD's and a Leupold VX II 2-7. Of course we don't have factory ammo here is Australia but we could get the brass and Grafs have the RCBS dies.

Well every development load with RL 15 and the Woodleigh 286gr from 58.5gr(2280fos) to 64.5gr (2480fps) shot 3 shots into less than 1/2 inch. I'm liking this 9.3 x 66/370 Sako Mag Calibre!

At 8lbs, with 5 in the mag and 375 H&H like performance its a potent package. Have not read Towsley's article but have read Boddington's and my only disagreement is on the recoil level. There's no free lunch and I reckon at 8lbs its worse than my 9lb 375 H&H but I think that is made even worse by the hard recoil pad that Sako always seems to use and the small surface area on the butt of Sako Rifles. Agreed its tolerable but no way is it light.

regards,
JohnT

Does anyone happen to have a link to the Towsley article?

I've always been interested in this cartridge. I'm not sure I can offer any practical reasons as to why it was developed, but, when the time comes, I'd choose it over the x62. (I don't own any 9.3's yet.) One thing that struck me is that it comes as close to the 375 H&H in a standard size package than anything I can think of. It fits in a standard size action and a standard bolt-face without any modification.

To those who dismiss the 9.3x66 Sako/370 Sako Mag. and don't consider it an improvement over the 9.3x62; I liken it to the 280 Rem. vs. the 7x64 Brenneke. Does the 280 Rem. really offer any worthwhile improvement over the comparable Brenneke cartridge? To me it doesn't, but I accept that there's room for both 7mm's. Why can't there be a spot for the 9.3 Sako alongside the 9.3 Mauser?

I think Sako probably wanted a proprietary cartridge. And you can't compare handloads in one and factory loads in the other. The Sako has more capacity and if you handload both to their potential I'm sure the Sako cartridge would prevail. Seems like a pretty good cartridge to me if you have use for something that big.

My worry about the 370 is that it is intense enough that the low recoil attributes of the 9.3x62 are lost. If so, then I can't see the point vs. a .375.

Also, you can fit a barrel chambered in 370sako to your favorite burnt out 270 Win and realize 375HH power outa ol' Betsy. For me , being a 35whelen hunter for a long time , I wanted same or better performance in a quality SS rifle and I can only get that in the M85 Sako. The powder of choice is VV550 in the 370, and probably work in the 9.3x62 as well

There are a heck of a lot of Old Mauser conversions in 9.3 x 62 and if you look at the trend with Hornady Superformance ammo the manufacturers think we need 100-200 fps more with our existing cartridges. IOW the "Free Lunch" - no more recoil - maybe. Certainly good marketing.

They may be right. Most likely Sako & the ammo makers were just scared off by their lawyers from producing the 9.3 x 62 to its full potential and at modern pressure limits of about 60,000psi as opposed to 45-50,000psi.

The success of the 375 Ruger though would make it tough going for any 9.3 so again it's the battle of the 9.3 vs 375 replayed 100 years later! I suppose this is called progress?

regards,
JohnT

JohnT,
So the 9.3x66 is a 'more available' 9.3x64?
Cheers...
Con

Don't really know Con as I have never played with a 9.3 x 64. It's (9.3 x66) available enough in Aust for us in that Beretta have cases in stock but as far as I know factory ammo is not avail. But Nioa indicated that they were expecting some by Nov this year which was kind of a surprise. Can't see many buyers out there and the price would be huge. The Sako cases are excellent BTW - made by Norma I understand.

As far as the 9.3 x 66 vs 9.3 x 64 - its like the 30-06 vs 300Win. The 9.3x64 is a much bigger & fatter case much more powerful and fully the equal of the 375 H&H. BTW you likeing your 358 wildcat on the 300RCM case? I am just amazed at how accurate my 300RCM is - only thing I did was put a cardboard shim under the recoil lug to free float.

regards,
JohnT

My guess is the ammo manufacturers can't bring the 9.3x62 up to modern pressures due to older firearms chambered for it so the x66 gives modern performance to those who don't roll their own.

The Sako cases are excellent BTW - made by Norma I understand

200 cases cost me around 425 dollars

John,
The first 358CRG was finished a few weeks ago. Using AR2208 and AR2206H ... 200gr pills are well into the 2800s at apparent low pressures and an ambient temperature well into the 30deg C. Other projectile weights are being tested now, mine is scheduled to be built in early 2010.

Here's a link to what's being done with it so far.
http://www.australianhunting.net/AHN_Journal/Articles/358%20CRG.htm

Cheers...
Con

Con, thanks for sharing that it was very interesting! I bet that 225 grain "pill" would work on just about anything that walked and wore fur for a living! Neat idea and without a belt! Please post the conclusion, I particularily like the idea that he was able to alter the magazine box to get more than two in it.

jimmyp,
The author of that article is one of the three nut cases that took a punt on a 358CRG (35/300RCM). I'm the C in CRG, first rifle was built by the R. When Manson cut the reamer I thought we'd stuffed up but then got our first lot of 300RCM brass and its 0.017" per side in the necks!

The G in CRG is running a 35Sambar (35/300WSM) and speeds (with 200gr) from the 358CRG is right on it's tail. Been a real surprise so far.
Cheers...
Con

What max velocities are you getting from the 370 sako Mag. using 250gr. bullets?

Con it sure seems like a fun project, I have no earthly need for such a rifle but a non belted 350 Rem Magnum in a reasonably light rifle sure looks like fun.

This is an older thread but I find myself looking into a new 9.3 build. After a good bit of research ive found the following.
The 66/370 is a stretched out 62 but has a thicker case web to handle the 60,000+ psi as opposed to 56000+ for the 62.
After running countless loads thru Quickload and talking to Accurate powder via email, there is only about 50 fps difference in them.
The 370, being proprietary, is harder to come by as brass and loaded ammo goes. The 62 has been around since 1905 and is very popular in Africa and Europe, while gaining in USA
As already stated, 370 brass is expensive, about $85 per 50 cases IF you can find them, as opposed to 30-35 for 62 brass.
Stores in most countries are more likely to have 9.3x62 than the 370SM.
As for the 9.3 vs 375 HH, past 100 yds, the 9.3 betters the 375 and does it with less recoil

For my build, i've decided to go with 9.3x62 and by going to a 24" barrel I can match the 370 with the 22" barrel I was going to build.
I could also trim and resize 370 brass to 9.3x62 to utilize the thicker web to work at higher than 56,000 psi. The Savage 110 action will certainly handle it.
If I decide later I want a tiny bit more, I suppose I could get an Ackley Improved reamer made.

The 9.3x66 is interesting to me. But, I have enough different reloading dies and non-mainstream cartridges as it is. And it would be a shoehorn mental justification considering the 338's and 375's. But, still interesting!