Thread: 338 ARC - An Early Guess At Reloading Data

Originally Posted by Pommy

What do you want to know?

Is factory ammo available in NZ?
What is the terminal performance like on game in both super and sub and at what range.
Question bomb I know!

No, no factory ammo in the country yet. It's likely going to be a couple of months at least. So this is all speculative...

Supersonic, Hornady are only initially releasing a 175gr BTHP match load that's going to be doing ~2000fps. It's not a hunting bullet and not especially fast. So I would not expect amazing, let alone consistent, results on game with that. But it is still making at least a 338 cal hole and hey, a lot of people still swear by SMK's so will no doubt try it anyway... Personally I have some Cutting Edge coppers which supposedly fragment down to 1300 so that's what I'll be trying to begin with.

Subs, I image the 307gr Sub-X will be like the 190gr Sub-X but biggerer and betterer. Not yet released as a component yet though.

If Hornady release a 150-165gr 338 VMax that would be money. I'm probably dreaming though.

Range with supers will be dependent on the bullet. I think my CE's will be limited to no more than about 250m. Range with subs as far as you can accurately account for drop and maintain ~900fps.

Originally Posted by Pommy

No, no factory ammo in the country yet. It's likely going to be a couple of months at least. So this is all speculative...

Supersonic, Hornady are only initially releasing a 175gr BTHP match load that's going to be doing ~2000fps. It's not a hunting bullet and not especially fast. So I would not expect amazing, let alone consistent, results on game with that. But it is still making at least a 338 cal hole and hey, a lot of people still swear by SMK's so will no doubt try it anyway... Personally I have some Cutting Edge coppers which supposedly fragment down to 1300 so that's what I'll be trying to begin with.

Subs, I image the 307gr Sub-X will be like the 190gr Sub-X but biggerer and betterer. Not yet released as a component yet though.

If Hornady release a 150-165gr 338 VMax that would be money. I'm probably dreaming though.

Range with supers will be dependent on the bullet. I think my CE's will be limited to no more than about 250m. Range with subs as far as you can accurately account for drop and maintain ~900fps.

Awsome thanks.
Will be interesting to see how that goes

unsure of capacity etc but i havea 338BR running 300r projectiles with N110 with great accuravy.

Originally Posted by Pommy

No, no factory ammo in the country yet. It's likely going to be a couple of months at least. So this is all speculative...

Supersonic, Hornady are only initially releasing a 175gr BTHP match load that's going to be doing ~2000fps. It's not a hunting bullet and not especially fast. So I would not expect amazing, let alone consistent, results on game with that. But it is still making at least a 338 cal hole and hey, a lot of people still swear by SMK's so will no doubt try it anyway... Personally I have some Cutting Edge coppers which supposedly fragment down to 1300 so that's what I'll be trying to begin with.

Subs, I image the 307gr Sub-X will be like the 190gr Sub-X but biggerer and betterer. Not yet released as a component yet though.

If Hornady release a 150-165gr 338 VMax that would be money. I'm probably dreaming though.

Range with supers will be dependent on the bullet. I think my CE's will be limited to no more than about 250m. Range with subs as far as you can accurately account for drop and maintain ~900fps.

Ive got brass and dies on BO over here but I dont expect to see components this year. I do like the idea of using N110 or Power pro 300MP behind a 161gr OEP, would be a crackin little thumper, will probably build 1 on Model 7 with an 18inch barrel

I've got dies. Forming brass from 6.5 Grendel is quite doable...



Those ones were not neck turned and came out too thick though. Having access to an annealing machine makes it much easier too.

Whats the length of the 175gr Cutting edge Pommy ?

Originally Posted by Pommy

I've got dies. Forming brass from 6.5 Grendel is quite doable...

Attachment 276049

Those ones were not neck turned and came out too thick though. Having access to an annealing machine makes it much easier too.

Where did you get your dies? I have been looking at modifying a full length 6.5grendel die to take something similar to the SAC neck and shoulder bushes.

Originally Posted by SixtyTen

Where did you get your dies? I have been looking at modifying a full length 6.5grendel die to take something similar to the SAC neck and shoulder bushes.

Overseas. Feel free to PM me.

Originally Posted by SixtyTen

I have been doing a lot of reading and research on the whole 1:3 twist thing as I thought it was a very interesting idea when I first heard about it. The below is what I have determined

- It seems to be mostly a hype thing driven by Q to try and make the 8.6 BLK seem special.
- 1:3 twist improves performance of segmented mono's by around 10%, maybe a little more.
- it seems to reduce effectiveness of jacketed subs through over stabilization
- It seems to be causing accuracy issues with jacketed projectiles and is even not flash with mono's (this is even with non Faxon barrels)
- Cannot shoot jacketed supersonic (they will explode on leaving the muzzle)
- Almost certainly cant use any lead projectiles, subsonic or not

Basically it limits you to mono copper projectiles and also reduces accuracy for a small increase in terminal performance .
Hornady have determined that a 1:8 twist is ideal for the 338 ARC, and that will allow 300gr + jacketed to stabilize. I plan to use a 1:7 barrel to use 300gr mono's which are a lot longer than jacketed, so need a bit more twist.

An interesting note around barrel twist that I came across was comparing twist rates for different calibers by the calibers/rotation rather than rotations per inch. doing this shows that a 1:8 .338 barrel is the equivalent to a 1:5 .223 barrel. or a 1:7 .308. Gives you a little perspective on how fast a 1:3 would be.

Solid info mate. This echos what I have been saying too since the release of the Qs 8.6blk. We went through all of this research 18 years ago with the .338 whisper. H D Jones stated at the time that a 1:8" twist would stabilize every .338 bullet on the market at the time which included the 350gr wildcat alloy tip which was a favorite for sub loads at the time. A 1:9" twist was plenty with 16" barrels and 300gr smks and Bergers.
The mono's are a little longer so 1:8" would be better.

Hornady 338 ARC dies have turned up along with Hornady 338 ARC 175gr Hornady Black Ammo this side of the ditch, no sign of any brass

There are Hornady dies here & 1 box of brass

À mate of mine is bringing me back from USA some Lee dies in 338 arc at the end of the month. I think I paid $50 us all up for them.

Why don’t you just ring Hornady technical services ? Wouldn’t they be able to tell you everything you need to know?

I've been loading for my mate's 8.6, which has a 1:7" twist. We found the 350 grain Maker pills aren't stable, but the 265 Accubond LRs are mint for both sub loads using 2205 or H110 at 1050fps, and 2208 for 2100fps, can't remember the barrel length, either 16" or 18" IIRC. I'm a bit put out that he can push the same pill as my 338 Lapua at 2/3s the speed in a short action cartridge and half the powder weight