I have wanted a new big bore now for a long time.
Now when norma makes cases for both the .500 Jeffery and .505 Gibbs it´s perfect.
I really like the Blaser R8 and you can get one in .500 Jeffery. But then I think about the big .505 Gibbs... If I build (not me but the gunsmith) one with the CZ550 action and a long 26" barrel. And Load the big case full of norma mrp powder to over 60KPSI.. What velocity to expect from a 600 grain bullet??
I remeber I have read here of one gibbs ownder that got 0ver 2640fps with a 600 grain woodleigh!? and he did not got any pressure signs even at that power level
is 2700FPS possible?

I eventually loaded a few more rounds of the load that gave me 2640fps. One of those loads chronographed at 2650fps and another at 2647fps. I never kept an average. I had no signs of pressure with these loads. I started with Ryan Breedings data published on his website. I think 2700fps is feasible. The 505 Gibbs is a great cartridge. I'm really happy with my choice -- now if someone comes out with a good supply of 577 T-rex brass....

What powder did you use?? and what barrel lenght do you have? the .505 gibbs really beats the shit out of the .500 jeffery

That was a thumper I bet!

26" seems a bit awkward on a rifle like this. I have 22" and it is a quick handler. Just about perfect I'd say for getting in the thick stuff and hand to hand distance. Just my 2 cents though.

Our 585 HE is a good strong GIBBS/Cheytac based

case with a belt. 650 gr at 3000 and no pressure signs.

Any gun that takes a Gibbs or that can be setup for Gibbs

takes our case. And there is plenty of good brass now.Ed

I used IMR4350. My gun only has a 23 inch barrel so I think a barrel 24-26 inches could definitely give you 2700fps.

Just reading this gave me a recoil headache.

[/quote]

quote:

I used IMR4350. My gun only has a 23 inch barrel so I think a barrel 24-26 inches could definitely give you 2700fps

Sound so good in my ears maybe 2750FPS with a 26" barrel?

I am thinking this way on the .505 gibbs.. you CAN load it to that power level if you want to... but then if you want faster follow up shots you can load it to 2300FPS with the same 600 grain bullet.
A nice cartridge to play with for sure...
But I still would want robgunbuilders (member here on AR) opinion on the .505 gibbs and hot loads. I know he has one and he know the big bore cartridges better then anyone
I hope he read this!
//Robert

Yes with a 26 inch barrel, 2700fps should be quite doable in the 505 Gibbs. You can get pretty close to .50BMG ballistics with one and with the right bullets it can be damn accurate out to pretty long range. Just work up slowly and watch for sticky extraction.I have no doubts about 65kpsi loads in that case either. I have a really nice one, that I built years ago but for some reason I just never fell in love with the Gibbs. Nothing wrong with it, just enjoy the smaller .50s and .600's more.-Rob

Thanks for that Rob

Have you load anything for your gibbs? remember any loads/velocity?

Cartridge : .505 Mag. Gibbs
Bullet : .505, 600, Barnes RNSP .049 50510
Useable Case Capaci: 145.740 grain H2O = 9.463 cm³
Cartridge O.A.L. L6: 3.750 inch = 95.25 mm
Barrel Length : 26.0 inch = 660.4 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 65000 psi, or 448 MPa
or a maximum loading ratio or filling of 105 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

139 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
ReloadSwiss RS 70 102.9 147.2 9.54 2668 100.0 65000 8660 1.256 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 60 100.1 141.1 9.14 2662 100.0 65000 8255 1.257 !DANGEROUS LOAD-DO NOT USE!
Elcho 17 99.1 139.6 9.05 2643 100.0 65000 8202 1.266 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-17 99.1 139.6 9.05 2643 100.0 65000 8202 1.266 !DANGEROUS LOAD-DO NOT USE!
PB Clermont PCL 511 100.6 143.9 9.33 2623 100.0 65000 8471 1.275 !DANGEROUS LOAD-DO NOT USE!
Ramshot Hunter 103.9 144.2 9.34 2621 100.0 65000 8459 1.275 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 62 101.3 142.6 9.24 2616 100.0 65000 8127 1.287 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H414 98.1 139.4 9.03 2615 99.9 65000 8460 1.279 !DANGEROUS LOAD-DO NOT USE!
Winchester 760 98.1 139.4 9.03 2615 99.9 65000 8460 1.279 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N550 100.5 137.9 8.94 2600 100.0 65000 8187 1.290 !DANGEROUS LOAD-DO NOT USE!
Norma URP 103.4 137.4 8.91 2598 100.0 65000 8054 1.285 !DANGEROUS LOAD-DO NOT USE!
Bofors RP19 ~approximation 103.5 137.5 8.91 2597 100.0 65000 8052 1.285 !DANGEROUS LOAD-DO NOT USE!
Norma 204 102.7 142.5 9.23 2597 99.2 65000 8517 1.275 !DANGEROUS LOAD-DO NOT USE!
Accurate 4350 102.6 137.9 8.93 2594 100.0 65000 7994 1.300 !DANGEROUS LOAD-DO NOT USE!
Somchem S365 105.0 140.3 9.09 2588 100.0 62568 7771 1.301 ! Near Maximum !
Bofors RP4 NT ~approximation 103.6 141.3 9.16 2576 99.8 65000 8183 1.288 !DANGEROUS LOAD-DO NOT USE!
SNPE Vectan SP 11 96.7 134.1 8.69 2574 100.0 65000 7750 1.288 !DANGEROUS LOAD-DO NOT USE!
Bofors RP4 ~approximation 105.0 141.1 9.14 2571 99.0 62762 8461 1.294 ! Near Maximum !
Raufoss RA4 105.0 141.1 9.14 2571 99.0 62762 8461 1.294 ! Near Maximum !
ReloadSwiss RS 52 95.5 132.5 8.58 2570 100.0 65000 7679 1.291 !DANGEROUS LOAD-DO NOT USE!
Norma MRP 105.0 147.2 9.54 2569 99.3 54098 9163 1.360
Ramshot Big Game 93.6 133.9 8.68 2568 100.0 65000 7651 1.289 !DANGEROUS LOAD-DO NOT USE!
Lovex S070 102.8 136.6 8.85 2560 99.9 65000 8025 1.300 !DANGEROUS LOAD-DO NOT USE!
IMR 4895 93.2 125.2 8.11 2560 100.0 65000 7654 1.298 !DANGEROUS LOAD-DO NOT USE!
IMR 4350 103.6 138.5 8.97 2557 99.7 65000 7998 1.286 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2209 105.0 140.3 9.09 2555 98.8 59617 8554 1.312 ! Near Maximum !
Bofors RP11 ~approximation 94.0 126.3 8.19 2554 100.0 65000 7623 1.298 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-15 94.0 126.3 8.19 2554 100.0 65000 7623 1.298 !DANGEROUS LOAD-DO NOT USE!
Raufoss RA11 94.0 126.3 8.19 2554 100.0 65000 7623 1.298 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H380 95.3 130.8 8.48 2552 100.0 65000 7754 1.301 !DANGEROUS LOAD-DO NOT USE!
Norma 203B 94.5 126.9 8.22 2551 100.0 65000 7570 1.300 !DANGEROUS LOAD-DO NOT USE!
Bofors RP7 NT ~approximation 97.3 131.8 8.54 2546 100.0 65000 7756 1.277 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H4350 105.0 138.0 8.94 2546 99.6 63894 7991 1.295 ! Near Maximum !
PB Clermont PCL 516 92.0 131.6 8.53 2545 100.0 65000 7675 1.294 !DANGEROUS LOAD-DO NOT USE!
Norma 203 old 95.8 130.1 8.43 2542 100.0 65000 7457 1.312 !DANGEROUS LOAD-DO NOT USE!
Bofors RP3 95.8 130.1 8.43 2542 100.0 65000 7457 1.312 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-19 105.0 141.1 9.14 2541 98.7 58141 8584 1.332 ! Near Maximum !
ReloadSwiss RS 50 93.7 131.0 8.49 2540 100.0 65000 7575 1.298 !DANGEROUS LOAD-DO NOT USE!
Bofors RP7 100.2 132.1 8.56 2536 99.7 65000 7890 1.299 !DANGEROUS LOAD-DO NOT USE!
Rottweil R907 100.2 132.1 8.56 2536 99.7 65000 7890 1.299 !DANGEROUS LOAD-DO NOT USE!
Elcho TR140 - preliminary data 94.9 131.7 8.53 2536 100.0 65000 7539 1.299 !DANGEROUS LOAD-DO NOT USE!
Rottweil R903 97.9 130.1 8.43 2536 100.0 65000 7376 1.312 !DANGEROUS LOAD-DO NOT USE!
Lovex S065 101.6 133.5 8.65 2536 100.0 65000 7697 1.303 !DANGEROUS LOAD-DO NOT USE!
Winchester Supreme 780 105.0 148.7 9.64 2536 98.8 61331 8233 1.308 ! Near Maximum !
IMR 4007 SSC 97.1 132.2 8.57 2536 99.7 65000 7885 1.299 !DANGEROUS LOAD-DO NOT USE!
IMR 4320 96.0 126.9 8.22 2535 100.0 65000 7347 1.287 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2206H 91.1 122.4 7.93 2533 100.0 65000 7431 1.300 !DANGEROUS LOAD-DO NOT USE!
IMR 7828 SSC 105.0 144.9 9.39 2533 97.0 54816 8915 1.352
Somchem S355 98.0 128.9 8.35 2532 100.0 65000 7408 1.307 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H4895 90.7 121.9 7.90 2532 100.0 65000 7385 1.302 !DANGEROUS LOAD-DO NOT USE!
Hodgdon Hybrid 100V 105.0 136.5 8.84 2532 100.0 62652 7342 1.307 ! Near Maximum !
SNPE Vectan SP 9 91.8 127.3 8.25 2530 100.0 65000 7396 1.297 !DANGEROUS LOAD-DO NOT USE!
Bofors RP3 NT ~approximation 99.0 132.1 8.56 2526 100.0 65000 7538 1.290 !DANGEROUS LOAD-DO NOT USE!
Somchem S361 105.0 150.3 9.74 2525 97.6 63801 8106 1.303 ! Near Maximum !
Rottweil R904 105.0 139.1 9.01 2523 98.0 61451 8182 1.313 ! Near Maximum !
Hodgdon VARGET 96.8 125.8 8.15 2521 100.0 65000 7387 1.293 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2208 96.5 125.8 8.15 2521 100.0 65000 7387 1.293 !DANGEROUS LOAD-DO NOT USE!
Bofors RP14 ~approximation 105.0 141.1 9.14 2517 98.5 56779 8478 1.347 ! Near Maximum !
Somchem S341 90.0 130.2 8.44 2515 100.0 65000 7182 1.300 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N560 105.0 144.1 9.34 2511 96.0 51671 9119 1.390
IMR 4064 97.4 123.6 8.01 2511 100.0 65000 7201 1.299 !DANGEROUS LOAD-DO NOT USE!
IMR 4831 105.0 135.1 8.75 2507 100.0 58304 7760 1.356 ! Near Maximum !
Lovex S062 95.0 124.2 8.05 2505 100.0 65000 7098 1.312 !DANGEROUS LOAD-DO NOT USE!
Lovex D073.6 90.8 125.7 8.15 2503 100.0 65000 6973 1.320 !DANGEROUS LOAD-DO NOT USE!
Somchem S385 105.0 142.6 9.24 2503 99.2 57520 8188 1.360 ! Near Maximum !
ADI AR 2213 105.0 142.6 9.24 2499 96.6 53526 8773 1.368
Accurate 4064 95.4 125.4 8.12 2498 100.0 65000 6963 1.337 !DANGEROUS LOAD-DO NOT USE!
IMR 3031 93.3 117.2 7.59 2497 100.0 65000 6808 1.311 !DANGEROUS LOAD-DO NOT USE!
Norma 201 92.2 121.1 7.85 2495 100.0 65000 7067 1.316 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N150 103.2 130.9 8.48 2492 100.0 65000 6984 1.310 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-22 105.0 142.6 9.24 2492 97.8 51073 8829 1.402
Bofors RP5/NP ~approximation 105.0 142.6 9.24 2492 97.8 51073 8829 1.402
Raufoss RA15 105.0 142.6 9.24 2492 97.8 51073 8829 1.402
Accurate 2700 97.1 136.1 8.82 2490 99.6 65000 7424 1.306 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N540 93.8 127.4 8.25 2489 100.0 65000 7033 1.311 !DANGEROUS LOAD-DO NOT USE!
Rottweil R902 93.9 121.7 7.88 2487 100.0 65000 6970 1.318 !DANGEROUS LOAD-DO NOT USE!
Accurate MAGPRO 105.0 150.0 9.72 2487 94.1 50386 9100 1.409
Hodgdon H4831 SC 105.0 142.6 9.24 2484 96.4 56158 8338 1.354 ! Near Maximum !
Norma 202 91.5 120.9 7.83 2481 100.0 65000 6849 1.314 !DANGEROUS LOAD-DO NOT USE!
Bofors RP2 NT ~approximation 91.0 121.3 7.86 2479 100.0 65000 6912 1.302 !DANGEROUS LOAD-DO NOT USE!
Lovex S060 91.8 119.9 7.77 2473 100.0 65000 6896 1.302 !DANGEROUS LOAD-DO NOT USE!
Ramshot Magnum 105.0 153.6 9.96 2465 98.1 50942 8510 1.398
ADI AR 2206 91.2 121.2 7.85 2462 100.0 65000 6796 1.304 !DANGEROUS LOAD-DO NOT USE!
Rottweil R901 90.1 115.1 7.46 2460 100.0 65000 6695 1.330 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N140 93.6 123.3 7.99 2457 100.0 65000 6591 1.315 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N135 99.4 121.1 7.85 2444 100.0 65000 6398 1.326 !DANGEROUS LOAD-DO NOT USE!
Rottweil R905 105.0 140.0 9.07 2426 95.4 49408 8412 1.430
Winchester WXR 105.0 139.5 9.04 2422 96.8 46767 8632 1.459
Bofors RP15 105.0 139.5 9.04 2422 96.8 46767 8632 1.459
Somchem S335 91.7 120.6 7.81 2419 100.0 65000 6352 1.328 !DANGEROUS LOAD-DO NOT USE!
SNPE Vectan SP 12 105.0 150.6 9.76 2416 95.4 46307 8807 1.454
Accurate 3100 105.0 141.1 9.14 2412 99.4 50641 7864 1.449
PB Clermont PCL 517 105.0 150.6 9.76 2411 95.2 46050 8803 1.458
Vihtavuori N133 93.4 114.9 7.44 2391 100.0 65000 6021 1.325 !DANGEROUS LOAD-DO NOT USE!
IMR 7828 105.0 137.1 8.88 2383 94.6 45373 8459 1.472
Hodgdon H4831 105.0 137.1 8.88 2383 94.8 49122 8030 1.436
Bofors RP5 NT ~approximation 105.0 143.8 9.32 2377 92.5 47971 8281 1.446
Alliant Reloder-25 105.0 140.3 9.09 2372 98.8 42174 8517 1.516
ADI AP 2214 105.0 146.4 9.49 2372 94.5 46343 8367 1.460
Vihtavuori N165 105.0 139.5 9.04 2361 97.5 48088 7697 1.458
Vihtavuori N160 105.0 135.2 8.76 2351 95.7 49502 7599 1.445
Norma MRP 2 105.0 141.1 9.14 2286 92.8 37804 8491 1.602
Bofors RP30 105.0 141.1 9.14 2286 92.8 37804 8491 1.602
Lovex S071 105.0 133.4 8.64 2275 98.0 41738 7564 1.580

2500 a piece of cake. Can obviously get close to 2600 without too much trouble with a 600 GRN. Looks like reloader 19 and 22 work good as well others. I have a 22" not sure how much will slow it down but 600 GRN at 2300 sounds like a winner in 22"

30-06 ballistics with 3x the energy & 10x recoil. Dang.

I stopped trying at 2400fps. The 600gn bullet at that velocity develops a lot of recoil. That was with 138gn AR2209, I settled on 2270fps for the 600gn bullet with 130gn AR2209, and I also worked up a fast load for the 525gn bullet using 142gn AR2209. They are both manageable loads and are about equivalent to shoot. However after recovering a few 600gn Woodleighs from Buffalo last year I have decided to slow my loads down to 2150 fps to guarantee better penetration & 90% weight retention. A monometal would be fine at any velocity you could shoot though. Please also note I have discovered my barrel is actually 0.507" diameter, and it takes about 10gn more powder to generate the same velocity as a true 0.505" barrel.

What brand of barrel?

quote:

Originally posted by gunslinger55:
What brand of barrel?

I am not sure what brand the barrel is. I bought the rifle second hand. It was a custom rifle built by the late Fred Wells. I am pretty sure it was a barrelled action from Granite Mountin arms that he stocked and fitted with sights etc. It was a bit too short for me , so I have had an inch spacer of black mahogany added to the stock. I also had it milled for Smithson scope mounts, but apart from that it is the same as when I bought it. I have put around a thousand rounds through it since I took posession in 2008, and it has performed faultlessly. It is also the smoothest action I own.

OK thanks. I find it interesting that there is so much barrel size variation with the .505 discussed. I have a CZ and I assume that since it shoots factory good a standard size bullet should be fine

quote:

Originally posted by Robgunbuilder:
... with a 26 inch barrel, 2700fps should be quite doable in the 505 Gibbs. You can get pretty close to .50BMG ballistics ...

Wow

quote:

Originally posted by PD999:

quote:

Originally posted by Robgunbuilder:
... with a 26 inch barrel, 2700fps should be quite doable in the 505 Gibbs. You can get pretty close to .50BMG ballistics ...

Wow

On 65000 PSI it would be good to check the bolt thrust calculations, too. It is probably getting close to a safety margin.

Bolt thrust is no where near the safety margin on a CZ550 or equivalent action. I'd probably proof test a 1917 enfield action though. Personally, I'd build a .510 wildcat on the Gibbs case so that I could shoot .50 BMG pulls. .505 bullets are hard to find and expensive compared to plinking with .50BMG pulls which I enjoy doing with my .500 a2.-Rob

CZ roll-stamped my .505 Gibbs action with a working pressure limit of 3800 bar or about 55,100 psi.
It is on the left side of the action below the wood line.

If the safety margin means that the action is engineered to handle 150 % of that pressure and attendant bolt thrust, but lawyers specify only 100 %,
then it can be loaded to 82,650 psi, no worries, eh?

The CIP pressure limit, wisely adhered to for the very rare original .505 Gibbs antique rifle, is 2700 bar or 39,150 psi.

I have no want or need to push my 505 past 600 grain bullet at 2300 fps...my neck and back, do not want any more...

Ed

When developing the .600OK, we were worried about the bolt thrust and ability of the CZ550 to handle 65kPSI. I blue pilled the action with two loads that were designed to deliver 85kPSI. The action was dimensioned fully before and after with no changes within measurement error. My .600OK has since digested a few 65kPSI rounds and has not come apart. While those loads are "stout" and I don't make it a regular practice to fire them, I'm not worried either.we all know how lawyers in the gun industry think.-Rob

On a side note, has anyone actually measured bolt thrust on any rifle?
I know what the theoretical calculation is, but it gives an absolute number, it doesn't take into consideration how much case grip there is on the chamber wall.
I have run my 505 at 2350fps with 600gr Woodleighs using both RE22 and RE25 in my CZ 550. I would be interested to know exactly what bolt thrust it runs in the real world. I remember reading tests were done with rifle that had been modified to have no bolt lugs, when fired, the bolt stayed put, showing the cases were in fact holding fast in the chamber.

Cheers.

No direct bolt thrust measurements only empirical evidence. The .600Ok in a CZ550 easily sends 750 gr bullets over 2700 fps and a 900 gr bullet to 2450fps. No CZ550 has ever failed to my knowledge. This is with a 26 inch, three groove barrel and bore riders. Others results may vary. No 505 Gibbs load will ever match that level of performance.

Rob, those are comforting facts to know, if 12000ftlbs can be called comforting.

quote:

Originally posted by 505ED:
I have no want or need to push my 505 past 600 grain bullet at 2300 fps...my neck and back, do not want any more...

Ed

I'm with you on that. A 570g bullet at 2300 fps out of my 500 Jeffery is fun. At 2400 fps it's less fun. At 2500 fps it's no fun at all.

When it starts to hurt it a good idea to stop!