casey3612
Beginner
- Apr 29, 2023
- 16
- 12
Does anybody have some good 338 Jarrett loads they would be willing to share? Thanks.
338 Jarrett
- Thread starter casey3612
- Start date
salmonchaser
Ammo Smith
- Dec 13, 2013
- 5,082
- 5,341
Welcome to the forum, I joined in 2013 with the same question. I’ve had good luck with Rl 26; H1000; Rl 25 and 7828. I’ve used RL 19 for my case forming and it actually seems to work well. I’ve had mine up to 3000 fps with rl 26 and 7828. My favorite load with Rl 26 and my old chronograph was right at 2950 however using the new Garmin it’s about 2920fps. I’ve had the rifle for about 20 years and have stuck with 250s first using partitions and for probably the last 10 years accubonds. I don’t have my old records but have some decent data on the above powders. H1000 is the slowest/26 the fastest. I’ll check my books when I get home.
- Nov 4, 2004
- 25,400
- 9,115
Welcome to the forum and congrats on being a member of the fast 338 club. Both are good places to be.
JD338
salmonchaser
Ammo Smith
- Dec 13, 2013
- 5,082
- 5,341
85 gr RL26 at 3.742 in my rifle gets me 2925 fps. With .456 groups, 250 grain accubonds. I have a Wyatt’s magazine box installed in my rifle to allow for chasing the lands. This load is .1 off
I wouldn’t trust my empirical data but came up with h20 capacity of about +4 grains on the 340 weatherby. That does not mean you can simply add 4 grains of powder, it just suggests you have extra capacity and “might be able to use more powder. Regardless the powder listed I’ve been able to use 340 data and carefully move up from there.
I’ve also had better luck with Remington cases vs Nosler.
Of the powders I’ve used H1000 is the only one readily available around the Northwest. Don’t know how you’ll do back east. I would be tempted to try the Vitafoy powders if you can find those.
I would suggest taking some of your fired cases and obtaining H20 capacity in your rifle, Then determine, if you have not, the overall length of your cartridge with your chosen bullet just touching the lands, or use 3.65 as anything longer can’t fit in the magazine unless you’ve modified it.
Several folks here will be able to run a quick load program, with that information and the powder you have available, give you a real good idea of where to start.
I’ve never used anything heavier than the 250s, I just don’t like recoil that much. The Jarrett is a first class elk thumper. I’ve killed quite a few at ranges as close as 30 yards to 501. I’ve only recovered one AccuBond and that was from a high shoulder, got both shoulders right at the big ball joint, leg bone to scapula, at 425 yards. Everything I shot with the 338 Jarrett was one and done, even the one I shot through the back leg getting the raking shot into the lungs.
I wouldn’t trust my empirical data but came up with h20 capacity of about +4 grains on the 340 weatherby. That does not mean you can simply add 4 grains of powder, it just suggests you have extra capacity and “might be able to use more powder. Regardless the powder listed I’ve been able to use 340 data and carefully move up from there.
I’ve also had better luck with Remington cases vs Nosler.
Of the powders I’ve used H1000 is the only one readily available around the Northwest. Don’t know how you’ll do back east. I would be tempted to try the Vitafoy powders if you can find those.
I would suggest taking some of your fired cases and obtaining H20 capacity in your rifle, Then determine, if you have not, the overall length of your cartridge with your chosen bullet just touching the lands, or use 3.65 as anything longer can’t fit in the magazine unless you’ve modified it.
Several folks here will be able to run a quick load program, with that information and the powder you have available, give you a real good idea of where to start.
I’ve never used anything heavier than the 250s, I just don’t like recoil that much. The Jarrett is a first class elk thumper. I’ve killed quite a few at ranges as close as 30 yards to 501. I’ve only recovered one AccuBond and that was from a high shoulder, got both shoulders right at the big ball joint, leg bone to scapula, at 425 yards. Everything I shot with the 338 Jarrett was one and done, even the one I shot through the back leg getting the raking shot into the lungs.
- Thread starter
- #5
casey3612
Beginner
- Apr 29, 2023
- 16
- 12
Thanks for the info. I'm going to see what powders I can get. I have a little 7828, r-22, and r-19 but not enough of any to really work with.
salmonchaser
Ammo Smith
- Dec 13, 2013
- 5,082
- 5,341
How long have you had the rifle; what are you currently loadings?
- Thread starter
- #7
casey3612
Beginner
- Apr 29, 2023
- 16
- 12
I've had the rifle for quite some time, Ray retired in 2010. Probably16-17 years. Most of my loads were 250gr. Sierra GK with r-19 or R-22 loaded to 3000fps through my Pact chronograph. Some were hotter, 3025,ish. No signs of pressure but common sense said probably too hot.
salmonchaser
Ammo Smith
- Dec 13, 2013
- 5,082
- 5,341
I always got a little jumpy getting over 3000. FPS. Didn’t really see the need with the results I was getting.
- Thread starter
- #9
casey3612
Beginner
- Apr 29, 2023
- 16
- 12
I stayed right at 3000 with fire formed Winchester .375 brass. Looking to get away from the fire form gun with 8mm mag. brass. Cuts out a couple of tedious steps. Had to run .375 brass into a 338 die to form a false shoulder, load with pistol powder, pack with cotton, and fire in fire form gun. Resize and final form in my rifle usually.
salmonchaser
Ammo Smith
- Dec 13, 2013
- 5,082
- 5,341
I only messed with the 375 process once. Bought every piece of 8mag I could find. I'm set for as long as I'll be shooting that cannon.
- Nov 4, 2004
- 25,400
- 9,115
salmonchaser
Ammo Smith
- Dec 13, 2013
- 5,082
- 5,341
It is, I use a starting load of RL 19 with what ever bullet I have handy, usually Hornady. Seat them long so they are just tight to the lands and shoot. Just moves the shoulder forward a little bit. With 250 grain bullets I’m still getting over 2600 fps and it’s well under MOA. I’ll fire form a box or so a year to ensure I have new brass for hunting season. I’ll take advantage of the fire forming sessions to shoot steel from various positions.
- Nov 4, 2004
- 25,400
- 9,115
That's a pretty good process you have developed.
The 250 gr AB is the perfect all around bullet. I actually pushed Nosler for 3 years to come out with that bullet and took the first animal with it.
It's my favorite.
JD338
The 250 gr AB is the perfect all around bullet. I actually pushed Nosler for 3 years to come out with that bullet and took the first animal with it.
It's my favorite.
JD338
longrangehunter
Handloader
- Jun 19, 2011
- 1,483
- 7
You could reach out to Kenny or Jay and ask them what are the top five or ten loads for that cartridge. The have files on every load ever made all cataloged on a data base now vs the 3"x5" cards that everything went on in the reloading room.
