Interesting comparison between 9.3 x 62 and .375 H&H

[bowji john]

As I'm finally getting the opportunity to start load dev for my 404 J and hoping for a KE & momentum of substantially more than that of the .375 (otherwise I needn't have bothered)

I thought I'd also revisit the differences between 9.3 x 62 and .375

I came across this interesting write up

Comparing the 9.3 X 62 Mauser and .375s – Lovin' The Big Bang

Posts about Comparing the 9.3 X 62 Mauser and .375s written by bigborefan

bigborefan.wordpress.com

As I develop and tweek both the 9.3 and the 404 J loads (the rifles I have) - I'd be very interested in real world findings (bullet weight, MV, KE and momentum) from those that have either

35 Whelen
9.3 x 62
.375
416
404
... and above

I quite like the formula for 'Terminal Effect' that is used in the above article - makes for an interesting comparison

 

[VIGILAIRE]

Good spot, great article, Just my kind of stuff for a wet Sunday! Interesting.

 

[Border]

I remember reading another old article by Kevin Robertson comparing 9.3x62 and .375 H&H a few years ago when he was helping Norma develop their DG range. I will see if I can find the magazine next time I am at my cabin. If my memory serves me right the 9.3 came out of it well using fairly convential SP's due to correct twist rate and not over spinning in the 375's case.

 

[bowji john]

My reference point for 404 J is Norma's commercially made 400 grain solids with a projected MV of 708 m per sec ((Kinetic Energy of 6449 J)) (don't know what length of barrel they would have used for their tests but since mine is 26" it should compare favourably)

I'll put my homegrown 9.3 286 grain Nosler partitions over the magneto V3 and get a base line for that too

Following the Norma route

Published data is as follow

35 Whelan 250 grain Oryx @ a MV of 2428 gives a KE 3273 FTLb
No figures given for Norma 9.3 x 62
.375 300 grain solids @ a MV of 2550 gives a KE 4333 FTLb
416 Rigby 400 grain solids @ a MV of 2375 gives a KE 5011 FTLb
404J 400 grain solids @ a MV of 2325 gives a KE 4802 FTLb

 

[Limpet]

@njc110381

 

[njc110381]

@njc110381

Thanks. The only Norma load I can find reference to in 9.3x62 is their 275gr solid at 2450fps, 3666ft-lbs.

From my point of view that puts the Whelen down 400ft-lbs under a round that is considered marginal and .008 under the minimum calibre. It's not a dangerous game cartridge from a legal standpoint.

 

[Alistair]

I'll dig out my 375 load data later today. I'm not exactly pushing the performance envelope with mine though so it's bog standard factory sort of velocities.

Al

 

[bowji john]

Yes please Alistair

That useful info on the norma 9.3 round thanks

The 9.3 x 62 referred to in the article has his 286 grainers going at 2630 ftps - he must have a larger case capacity than I have as QL is moaning like hell well below those velocities for my cases

 

[Alistair]

So for .375H&H my loads provide energies as follows (all 24" tube, not pushing them hard):

300gr Sierra Gameking - 2399fps chronoed - 3844ftlb
300gr Barnes TSX - 2440fps chronoed - 3967ftlb

According to the data I've seen online, all the factory rounds claim around 2500-2550fps (I'm hugely sceptical of any and all manufacturer claims in this area as I've never actually seen any box figure reached in a standard hunting rifle. I'd expect 2450ish if they are actually chronoed). I've discussed loading for this round with people I'm inclined to trust at least a bit who are claiming a true 2600fps chronoed, but usually from 25" tubes and with double base powders.

That being the case I think 375H&H can reasonably be expected to deliver between 3900ftlbs (factory) and 4500ftlbs (hot double base powder charge in longer barrels) with a 300gr bullet.

Al.

 

[bowji john]

Brilliant Alistair

It is why I'm keen to garner real data

I know there are loads of variables but real achievable momentum and kinetic energy values will make for an interesting comparison

I'll also chrono my shop bought Norma to see if they are 'as fast as advertised'

 

[Nkawu]

Great thread, and very interesting reading. From my understanding the historic standard load for the 404J is a 400 grain bullet at 2150 fps. If you read Kevin Robertson’s book on buffalo he suggests that the actually velocity was well below that, and may explain why the 404J performed so well (mild recoil and bullets not deforming etc). With modern propellants and our well developed heavier projectiles the statistics of 404J can be boosted, but does it really need to be?

 

[CarlW]

In my .375, I get an average of 2526 fps (chrono'd) with 300-grain Barnes TSX, using H4895, from a 21-inch barrel. If my maths are correct, that's 4229 ft lbs.

 

[Alistair]

In my .375, I get an average of 2526 fps (chrono'd) with 300-grain Barnes TSX, using H4895, from a 21-inch barrel. If my maths are correct, that's 4229 ft lbs.

Wow, not bad! I'm using N150, because I can source it, but I think 4895 pips it for velocity, easy. Would you say your loads are 'hot'?

Al.

 

[CarlW]

Wow, not bad! I'm using N150, because I can source it, but I think 4895 pips it for velocity, easy. Would you say your loads are 'hot'?

Al.

I haven't seen any pressure signs and I am not at maximum. I have always found H4895 to be a fantastic powder: I use it in both .375 and .308. However, it isn't REACH-compliant so I'll need to think again once these dozen tubs are gone.

 

[bowji john]

In my .375, I get an average of 2526 fps (chrono'd) with 300-grain Barnes TSX, using H4895, from a 21-inch barrel. If my maths are correct, that's 4229 ft lbs.

And that was a sweet load to shoot - very little recoil that I can recall

 

[sh1kar]

Just looking through my reloading book

.375 82g N160, Hornady RN interlock 270g, 2580fps
.375 80g N160, Woodleigh soft point 300g, 2525 fps

S

 

[Heym SR20]

Good article that proves its the size and type of bullet and where its placed that is far more important than a few thou or mm and grains.

The same article has been written numerous times, and also debated on here on the difference between the 6.5 CM, 6.5x55, 7x57, 270 win, 308 etc etc

But its funny to think that we constantly debate the inadequacies of a 100 to 150 gn bullet and the differences in their ability / or lack of ability to drop a 150kg Red Stag, yet a 280 to 300 gn bullet is deemed more than enough to drop a 750 to 1,000 kg of aggressive Buffalo.

 

[zambezi]

My .375H&H throwing [Sako manufactured] 270gr Barnes TSX projectiles was chrono'd [Magnetospeed V3] at 2680fps.

Sako claim that cartridge [478D] should be running at an MV of 2660fps. Near enough. That equates to 4233ft/lb at muzzle.

Home loads with same projectile use 70gr N540 to achieve a chrono'd 2625fps. Near enough, and very accurate.

 

[takbok]

Good article that proves its the size and type of bullet and where its placed that is far more important than a few thou or mm and grains.

The same article has been written numerous times, and also debated on here on the difference between the 6.5 CM, 6.5x55, 7x57, 270 win, 308 etc etc

But its funny to think that we constantly debate the inadequacies of a 100 to 150 gn bullet and the differences in their ability / or lack of ability to drop a 150kg Red Stag, yet a 280 to 300 gn bullet is deemed more than enough to drop a 750 to 1,000 kg of aggressive Buffalo.

there are video's on youtube of a clown with a 10mm Auto 1911 pistol taking buffalo with 200gr hardcast bullets producing 750 ft.lb - doesn't take much.

 

[Selous]

I have just had a phone call from my local FLO to say that my variation for a 375 and 458 has been approved
Hopefully my ticket will be back with me later this week! Very very exciting!
My plan is to go with a 375 initially as recommended on the Cape buffalo thread and see how things go. Whilst the 458 is a bit of a boomer I should be able to load it incredibly cheaply for range practice by using 410g jacketed 45/70 bullets which are cheap as chips