I just started reloading and I could use a little help. I am working up some test loads for my CZ550 American 6.5x55. I am using 140 gr Hornady SST's, Norma brass, and Fed 215 primers. I meant to get some IMR 4350 but picked up H4350 by mistake. I have read that I can interchange these, is that correct? Next question: The Hornady 7th edition manual lists a max load of 41.4 gr of IMR 4350. This is a reduced load for the old military actions. I plan on working up slowly starting out at about 38.5 gr, but I am just wondering how far past the listed data some of you guys would go. Thank you for any help.
6.5x55 help needed
- Thread starter Woodsie
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Assuming 23.62" barrel (CZ website)
HNDY .264"/140SST
OAL: 2.905 (HNDY 8th ed manual)
QuickLoad tells me:
IMR4350/41.5gr -- 53,097psi/2,772fps
Hgd4350/41.5gr -- 52,743psi/2,769fps
In other words, statistically no difference.
As to exceeding these loads by any significant amount, I wouldn't if you want to be kind to your brass.
You are already approaching case/primer pocket (not action) pressure limits of a healthy 55ksi.
HNDY .264"/140SST
OAL: 2.905 (HNDY 8th ed manual)
QuickLoad tells me:
IMR4350/41.5gr -- 53,097psi/2,772fps
Hgd4350/41.5gr -- 52,743psi/2,769fps
In other words, statistically no difference.
As to exceeding these loads by any significant amount, I wouldn't if you want to be kind to your brass.
You are already approaching case/primer pocket (not action) pressure limits of a healthy 55ksi.
NCsmitty
Member
H4350 is an Extreme powder from Hodgdon and is far less temperature sensitive than IMR4350. The only powder from IMR that is NOT temperature sensitive is 8208 XBR, all other IMR powders are old formulas that can give you variations in pressure and velocities if used in climates the have variations in temperature extremes.
I have used H4350, Rel-19, Rel-22 and H414 in my M98 6.5x55 Swede with different bullet weights, and all work well. I don't use IMR4350.
NCsmitty
I have used H4350, Rel-19, Rel-22 and H414 in my M98 6.5x55 Swede with different bullet weights, and all work well. I don't use IMR4350.
NCsmitty
Coltdriver
Member
So for your next pound of powder try some reloader 22.
I had a CZ550 in 6.5x55. RL22 and 140 grain bullets were the best shooting combo. The CZ is only 1 in 10 twist and the 140's are really the limit for that twist, just my opinion. I use the same powder and bullets in an M38 and it too shoots great with this powder.
The problem I had with my CZ was that the chambering was cut to original 6.5X55 Swedish spec. This means they have a long throat to shoot 160 grain bullets. But the 1 in 10 twist was not tight enough to stabilize them. You can still get outstanding results even with the jump that a 140 makes in that long chamber.
If you search for some Float Pilot posts he has a lot RL22 info here. Its where I discovered the powder for a 6.5 X 55.
I had a CZ550 in 6.5x55. RL22 and 140 grain bullets were the best shooting combo. The CZ is only 1 in 10 twist and the 140's are really the limit for that twist, just my opinion. I use the same powder and bullets in an M38 and it too shoots great with this powder.
The problem I had with my CZ was that the chambering was cut to original 6.5X55 Swedish spec. This means they have a long throat to shoot 160 grain bullets. But the 1 in 10 twist was not tight enough to stabilize them. You can still get outstanding results even with the jump that a 140 makes in that long chamber.
If you search for some Float Pilot posts he has a lot RL22 info here. Its where I discovered the powder for a 6.5 X 55.
Another fan of RL-22 and Hornady 129 and 140 sp's. Have a 550 fs 6.55 x55 , and like M70 owned, the throats are long and can seat the bullet pretty far out there. The accuracy with the 140 grainers improved with loads towards max velocity (using rl-22) for a modern action.
WYOMan
Member
6.5 X 55 with 140, or 142's and Reloader-22 is the best I've found yet.
RPRNY
Member
The CZ550 will be built to meet CIP pressures for the 6.5 x 55 of 55,000 psi (Piezo method). Loads up to that level with Norma brass (also CIP standard) should be fine. I would not exceed the CIP Max pressure level nor would I counsel you to. I rarely find that max loads deliver max accuracy. With the 1:9 twist and 140 gr bullet, I would back off Max by 2 grs and see what that was doing for accuracy. The Swede is not all about FPS, it's about optimal sectional density and ballistic efficiency delivering deep penetration well out to 500 yards with @ 2500 - 2600 fps MV. I would welcome your observations on SST performance. I like the good old Interlock SP 140 but have not tried the SST in 6.5
Kachok
Member
Yeah RL-22 is the cat's meow for 140gr 6.5x55, 46.5gr is the classic load that seems to work well in all of them. I only use IMR-4350 for my 120gr Ballistic tips, RL 19 is a GREAT powder for 129gr SSTs my Tikka shoots one hole groups with a 45.5gr charge.
togojeff
Member
Kachok, did you happen to chrony your 129 SST's with your 45.5 RL-19 load?
I have achieved outstanding accuracy with 46 gr of RL-19, but my speed seems to be subpar. My Hornady 8th edition reloading manual indicates I should be
around 2750 with this amount of powder but all I am getting is 2550 average.
I did seat my bullets out to 2.920". Would 20 thou make that much difference?
Float Pilot
Member
Kachok
Member
No I did not, but that is streight from Nosler #6 they have it at aroud 2,650fps in a 23" tube. Feels a bit more peppy then factory loads so I don't doubt that one bit, just not as peppy as my 140gr RL22 loads. I doubt seating your bullets out an extra .020" would make that much difference in terms of speed, but a combanation of factors could.
togojeff
Member
Awesome group Float Pilot!
I'm getting close to that with 129 SST's and RL-19.
Love my T3!
Thanks for the reply Kachok. I don't think I will worry about the velocity, could be a number of things as you say, including my chronograph.
What matters at that kind of speed it will do for whitetail out to 300 yds
which is as far as I care to shoot anyways.
I'm getting close to that with 129 SST's and RL-19.
Love my T3!
Thanks for the reply Kachok. I don't think I will worry about the velocity, could be a number of things as you say, including my chronograph.
What matters at that kind of speed it will do for whitetail out to 300 yds
which is as far as I care to shoot anyways.
BrainOnSigs
Member
No chrono done. My hunting buddy came up with this load.
Manitou
Member
Varget has served me well in the 6.5 x 55 for several years. I am currently using 37 grains under a 120 gr Nosler Ballistic tip
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