Ok I need to use H4350 because it’s more available here in Oz than re17....and I have it on hand. I have loads made with the following charges of H4350 behind the 750gr woodleigh soft nose.

145gr h4350
150gr h4350
155gr h4350

I am looking for 2250 to 2350 FPS. Maybe not the most efficient powder etc but I just want to check it’s safe.

Would someone be willing to run these loads through quick load please?

Cheers pc

when Neal designed the 550 GIBBS, and paid for the brass to be made, he sent me some of the cases - He and I were on the phone together as I experimented with various bullets, and decided to try the .585 bullets I had around from a 577 project - at that point, exactly TWO people had held the case outside of the manf. I designed the 577x505 - which is actually funny if you take the history of the case ...

the 577 express (BP) lead to the 577/500 express, which is the parent case of the 505 gibbs, which this fun part comes in - Neal invented the .550 caliber, and I "re-invented" the 577/500 case into the 550 Flanged - a 577/500 necked to 550 and improved .. which resulted in the same case capacity of a 505 gibbs, plus a bit for bore and did the ATF paperwork for such, as well as the 550 express. ..

I think Neal always had the gibbs case in mind, however, (many times) we were hunting somewhere in south Texas, and had long discussions about 550s .. I think the first time was right as the 550 magnum cleared the ATF .. but it's been many times and many years ago .. so I couldn't give you a date from memory -- 2004? 2005? and we discussed my mad concept of the 550 flanged . in fact, my avatar is me shooting, at Hogkiller's place, the 550 BPE .. we loaded cases with a sh!t load of elephant or swiss ffg and had an amazing fireball - Keith's idea .. went from concept to boom in about 10 minutes, BEFORE the nitro was loaded, in proper order of carts .. BPE before NE.

these were heady days - buying lots of tooling, high end pressure testing equipment, spending hours and days in the shop, on the phone, on the computer working with QL and many others, and every supplier missing deadlines by at least double.. build double rifles, working with friends, trying new things, and figuring it all out


Going onwards,

*I* , again, was on the phone with Neal when the first human stuck a .585 into a gibbs case, which lead to the 577 BME and I gave it to Boommie, I meant one to use h335, to reduce ejecta mass and reduce recoil.


I have no clue what loads Ed decided to use in the 585 HE -- in his words, deigned from the 577/500 derimmed case -- He posted loads, on ammoguide.com for rel25 and win760 ... and even h4350, is WAY too slow powder to use for this case

my own work the 550 flanged, which focused on rel 22 and 25, proved to be too slow, as well


ammoguide lists some loads for the 577 NE, which, from longer term memory than the 550 work, match Ross's published loads, using rel15 and h4831 .. though the rel 15 stuff might be the work Richard and I did because Ross's data GROSSLY overstated vels - we couldn't get over 1875 from Ross's 2050 loads

sorry for the ramble - but it was nice to walk down memory lane, and recall that Dave, Rob, Neal, Rip, MM, and I all lived through this period of crazy wildcatting the big stuff

Thanks Jeffo, interesting read.....I figure those loads I have rolled will be safe, given that there are loads for the regular .585 Nyati (2.8" version) using 150gr of h4350 behind the 750.

Varget probably MIGHT be better but you'd have too much room in the case and probably need fillers

Maybe I wont even reach 2250 fps with these

quote:

Originally posted by PC:
Ok I need to use H4350 because it’s more available here in Oz than re17....and I have it on hand. I have loads made with the following charges of H4350 behind the 750gr woodleigh soft nose.

145gr h4350
150gr h4350
155gr h4350

I am looking for 2250 to 2350 FPS. Maybe not the most efficient powder etc but I just want to check it’s safe.

Would someone be willing to run these loads through quick load please?

Cheers pc

155gr h4350 - 55k PSI, 2355 fps (26" tube)
150 - 50k - 2282
145 - 45k - 2209

with 3.858 COAL

Jiri

quote:

Originally posted by Jiri:

quote:

Originally posted by PC:
Ok I need to use H4350 because it’s more available here in Oz than re17....and I have it on hand. I have loads made with the following charges of H4350 behind the 750gr woodleigh soft nose.

145gr h4350
150gr h4350
155gr h4350

I am looking for 2250 to 2350 FPS. Maybe not the most efficient powder etc but I just want to check it’s safe.

Would someone be willing to run these loads through quick load please?

Cheers pc

155gr h4350 - 55k PSI, 2355 fps (26" tube)
150 - 50k - 2282
145 - 45k - 2209

with 3.858 COAL

Jiri

Thanks Jiri,

So pretty safe although the 155g loading is probably getting a little to high in pressure ?

It is looking like 150gr is about ideal for my purposes. Just need to get out and shoot these loads now for the smith !

55k PSI is fine in bolt action rifle, cartridge is designed for 65k psi+

But depends on for what PSI is your shoulder designed ;-)

155 gr of RL-17, which is starting load, generates 53k PSI and 2430 fps (estimated by QuickLoad). Real world fps is 2400, so quickload pressure estimation is IMHO pretty close to real world too. And it is really fine load, so I believe 53 or 55k PSI will make no real difference.

Jiri

quote:

Originally posted by Jiri:
55k PSI is fine in bolt action rifle, cartridge is designed for 65k psi+

But depends on for what PSI is your shoulder designed ;-)

155 gr of RL-17, which is starting load, generates 53k PSI and 2430 fps (estimated by QuickLoad). Real world fps is 2400, so quickload pressure estimation is IMHO pretty close to real world too. And it is really fine load, so I believe 53 or 55k PSI will make no real difference.

Jiri

Thanks Jiri,

Load density with H4350 is pretty good with the 155gr load and also ok with 150.....obviously a little more space with 145 but nothing to dramatic.

Update on the H4350/AR2209 loads.

Rifle weighs 12.76 pounds:

Barrel length = 23”

I fired all three loads 145gr quite accurate 150gr not so much. The 155 gr load was pretty good and the speed was 2232 FPS with 750gr Woodleigh RNSN, right about where I want the speed and all you want in a 12.76 pound rifle. It’s pretty full on and you know you’ve pulled the trigger

Great!

Fps you have is just right for the bullet. Look at the same bullet at 2403 fps fired into water jugs. It holds together, but overexpaned I think. Photo here: http://585he.cz/

Jiri

PC,

That expanded bullet Jiri showed would sure be something into the middle of a big red roo or up the rear end of a pig. Be interesting on emus

Jiri yes it probably is about right for this bullet, although water does do funny things to bullets. I note yours is 10.86 pounds......best part of 2 pounds lighter than my rifle. Gee that would be a handful at 2400 fps !

Mike I've seen a Feral Horse (my friend) shot one with his .585 Nyati using the 650gr woodleigh BP .577 RNSN at around 2500 fps or there abouts texas heart shot running away and it went down like struck by lightening. Now those BP woodleighs run well above recommended impact velocity are great on soft skinned stuff

At 10 pounds, 8.4 oz, some recoil is there. But not that bad at all

https://youtu.be/W4iYhHg2izg

Jiri