Well, the topic pretty much says it all.

I know RIP has pushed his .470 Mbogo up to 2685 fps, and I have pushed my .416 Rigby well past its original 400 gr. load of 2400 fps figures by using modern powders.

Does anyone know HOW FAST you can pust a .505 Gibbs' 525 gr. bullet, by using modern powders, without running into pressure problems?

THANKS for any info you can provide!

In what action? Assuming an action that can take say 60 kpsi, I'd expect 2700 fps to be reasonable, not that I would want to shoot such a load!

quote:

Originally posted by Paul H:
In what action? Assuming an action that can take say 60 kpsi, I'd expect 2700 fps to be reasonable, not that I would want to shoot such a load!

I was thinking about a CZ550, but I have no idea what the action yield strength is.

I think I'll have to pass on hot rodding a gibbs, but I would like to watch

quote:

Originally posted by Gringo Cazador:
I think I'll have to pass on hot rodding a gibbs, but I would like to watch

Billy, I will bring the chairs and Camera.
Do not want to sit to close though.

Billy, I'll load some ringers and let you chrono them at the next bubba shoot. When we were at the hunt I shot mine with the max load in the A-Square manual and I'll bet bunch of beer they were in the 2500 range.

Woodsracer, the big CZ is stamped 3800 bar so you should keep the pressures around 57,000. Unless you like eating into safety margins. I'm sure 60,000 is technically safe but so is base jumping. I'll pass on both, thanks.

Yep, with the .505 Gibbs head size, considering bolt thrust, the CZ folks decided to designate the action pressure max as 3800 bar.

1 bar = 14.5036 psi
3800 bar = 55,114 psi

One should not try to build a .408 CheyTac on the CZ 550 Magnum action. No further comments from my seat in the peanut gallery.

quote:

Originally posted by woodsracer:
Well, the topic pretty much says it all.

I know RIP has pushed his .470 Mbogo up to 2685 fps, and I have pushed my .416 Rigby well past its original 400 gr. load of 2400 fps figures by using modern powders.

Does anyone know HOW FAST you can pust a .505 Gibbs' 525 gr. bullet, by using modern powders, without running into pressure problems?

THANKS for any info you can provide!

Years ago Jack Lott wrote an article for Guns & Ammo about a 505 Gibbs built by Ryan Breeding as I recall he stated that 600 grainers were going 2700, since my memory was not clear I called Ryan and he said that was not sure about 2700 fps but he believes they were 2600 and change.He also stated that he no longer pushes them that fast,and the cases being used at the time of the article would hold more powder than the newly manufactured case of today. Mr. Breeding also stated that that he now beleives that there is no reason to push a 600 grainer that fast and absorb the tremdous recoil generated by such speeds. As to the question of 525 grain bullet speeds Mr. Bredding said that had not experimented with the 525's as to how fast that they could be pushed

woodsracer,
My only response is "Why?"

quote:

Originally posted by BigBores:
woodsracer,
My only response is "Why?"

I was just thinking of pushing a 525 grainer to 2500 fps, since when it arrives on target, it would be at the "MAGIC 2400 fps." ......and possibly a few at 2600-2700 "just for the experience."

You could probably reach that goal safely with the 470 Mbogo. I've driven 540's to 2400 fps without a problem. But why loose the shootability of a cartridge that will penetrate without a problem.
Take good care,
Dave

i am having one of ryan breeding rifles built my load is a 600 grainer 2550 out of a 22" stainless barrel.

Tiggertate,

The first time I laid eyes on you 505, when we were hunting in South Texas a while back...........that I would end up being the proof test dummy

I was the test dummy that weekend, Billy. Couldn't find a tire to tie it too! Found two pair of safety glasses and put them both on, LOL. Couldn't keep the forearm in my hand. Checkering really is functional in a gun like that.

2500 is not very shootable in my rifle (10.5 lbs). When I get serious about filing the sight I'll also work down to about 2350 with the 525 gr bullet.

I don't see a need to go to either 600 gr or over 2400. But the extra room is there for those who might want to.

Tiggertate,

So what I think your trying to say is you did not shot five shot groups off the bench Post some more pics of that gibbs.

My .505 Gibbs, built on a Vecktor action has launched 600 gr bullets in excess of 2600fps. No extraction problems or loose primer pockets after 3 reloadings. Very Nssty recoil though!-Rob

quote:

Originally posted by Robgunbuilder:
My .505 Gibbs, built on a Vecktor action has launched 600 gr bullets in excess of 2600fps. No extraction problems or loose primer pockets after 3 reloadings. Very Nssty recoil though!-Rob

Sounds interesting...........who needs a .585 Nyati!

quote:

Originally posted by tiggertate:
I was the test dummy that weekend, Billy. Couldn't find a tire to tie it too! Found two pair of safety glasses and put them both on, LOL. Couldn't keep the forearm in my hand. Checkering really is functional in a gun like that.

2500 is not very shootable in my rifle (10.5 lbs). When I get serious about filing the sight I'll also work down to about 2350 with the 525 gr bullet.

I don't see a need to go to either 600 gr or over 2400. But the extra room is there for those who might want to.

I agree totally! I had a magnum Mauser rifle chambered for the 505 gibbs an 135gr. RL22 would really get your attention.I was shooting off the bench and making a ragged hole at 50 yards, but oh!MY, the recoil was fierce and I got a head ache each session with that 10lb beast. My 500 Jeffery weighs 10.8 lbs and I don't know how I would like it.

Billy, it looks pretty much the same. Only I know I have another 200 hours in it, LOL. So far I've spent 199 hours looking at it and 1 working the proud wood down to the trigger bow. Next week we put the tip on and continue making sawdust.

Here it is with some water:

Wow Harry that's a nice looking stock. Are you putting on an ebony forend cap? What about the pistol grip?
Take good care,
Dave

quote:

Originally posted by Robgunbuilder:
My .505 Gibbs, built on a Vecktor action has launched 600 gr bullets in excess of 2600fps. No extraction problems or loose primer pockets after 3 reloadings. Very Nssty recoil though!-Rob

You play with HURTIN' BIG CARTS. how nasty in comparison to a 378 weatherby? I got an idea about your cartridges when I posted an interest in true bigbores. jeffeosso said it best when he said to take the recoil pad off of a 460 Weatherby, place it on my forehead and if I can hit what I am aiming at, I can step up to your carts. All kidding aside after viewing your posts ( and hubels & jeffes) you guys play with big numbers. I am truelly convinced of the abilities of the AR carts. and am already lining up for next winters project. But I know a couple of young friends with enough piss & vinegar to try one of your projects!

Woodsracer a -.585 Nyati will drive a 750gr, .577 diameter bullet to well over 2600fps pretty easily. The full length Nyati case will hit 2700 fps. It's a major step upwards in power over a .505 Gibbs. The Nyati however, is a crappy case design, while the Gibbs is just plain beautifull! Either cartridge will flat stop anything on this planet with a heartbeat!
.366 torque- Well Jeffe got it about right. I let him fire my Nyati at a Bubba pig hunt two years ago and I'm sure he remembers the opportunity. Properly built its not that bad, I even made a running shot on a pig at about 40 yrds with it. Probably the only documented running shot with a Nyati ever witnessed. .470 Mbogo was there to corroborate the story.
Any un-braked .505 Gibbs shooting 600 gr bullets at 2400 fps plus is gonna hurt!-Rob

Harry,
WOW.. i fully understand the 200 hours!!

jeffe

quote:

Originally posted by Robgunbuilder:
Very Nssty recoil though!

Really???

Hey Harry (tiggertate),

Nice piece of wood...........I'd like to have one like that.

you going to do a short forearm, I'd do a 8 3/4 9 inch..........well might need something to hold on too, its a boomer no doubt. When I grow up, I'm going to build a big boomer of somekind.

Thats a fine rifle, I've seen it up close.

Hi, Dave. Yeah, it gets an ebony fore end and I have the trap door grip cap for it. The wood is a blank Gringo Cazador sold me. He has the sister blank on his 404J and it looked so good I couldn't resist. Rob, it has the single-stack system you designed for Ed. Works great!

Billy, I'll shorten the fore end some but I haven't decided how much yet. It's too long now, though.

quote:

Originally posted by Robgunbuilder:
Any un-braked .505 Gibbs shooting 600 gr bullets at 2400 fps plus is gonna hurt!-Rob

True. I found backing off to 2,325 fps to add greatly to the "shootability" of the rifle, as 470Mbogo alludes to. Even at that speed, short range terminal performance of premium softs gave clear indication of maximum stress. I plan to use 2,250 fps, next time out.

Basically, the 500a2 can do just about anything a .505 Gibbs can do other than compare in the looks and classic comparo.-Rob

The 505 Gibbs I built in 1993 on a P14 action is still going strong. It only wieghs 10.5 pounds so it packs a kick.

This was before the A Sq book was well known, so all we had was a load from a disk program then.
I have shot about 100 or so strong loads from it using a Fed 215 primmer and IMR 4350 with a 525 gr A Sq or Woodleigh bullet at a cronograhped 2550 fps.
Of course you have to use a bag of bird shot to help reduce the recoil, otherwise you will inflict severe pain on your shoulder.

The most common loads I shoot are the 600 gr cast bullet at 1800 fps. This load is like shooting an 338 mag for recoil and has all the accuracy I need. I have put in some 1 1/2" groups at 100 yds with a 2.5 power scope.

Just have not found a tusker loose in my back yard to try the Barnes soilds on.

Jim Wisner
Custom Metalsmith