I am sure this question has been asked before and I have tried to search the old postings. Please forgive my ineptness or laziness if I am beating a dead horse. Can the 505 Gibbs be loaded to fire a 600 grain bullet at 2400 fps in a CZ 550? In my research of old posts I saw that someone said trying to load the 505 to 2500 fps with a 600 grain bullet is crazy with anything short of a 50 BMG action.

I have convinced myself that I am going to purchase a CZ 550 Safari Classic in 505 Gibbs right after Christmas (I’ll have a bonus check that has got to go toward a new gun)!
I would like to be able to achieve the above ballistics (600@2400) in the said rifle.

I know I could do this easier/cheaper with a 500 A2, but would like to know if I could do it safely with the CZ 505 (I am currently waiting on to many custom jobs and would like to have something to shoot right away). Someone said the CZ is stamped 55KPSI; would this load be in that range? At what point would there be bolt thrust problems?

In summation;

1. Can the 505 Gibbs in the CZ 550 be safely loaded to launch a 600 grain bullet at 2400 fps (could some one please provide at least a starting load)?
2. If not, how fast can the 600 gain bullet be safely pushed in this rifle/cartridge combo?

The answers to this post will probably make my decision for me (on whether or not to buy the rifle). I am going to order dies this week, so please help me if I am about to waste some bucks!

Thanks for any responses…….

Matt V

the field reports on teh cz/505 are that
1: they don't feed
2: the bolt is too small
3: the MUST be bedded and crossbolted

can you take 600gr to 2400 with a gibbs? without a doubt. can you do a 510 wells, on a cz 416rigby action and match that, with cheaper bullets, that will fit the action?

yes

jeffe

A 505 Gibbs will easily push a 600 gr pill to 2400 fps and beyond. As Jeffeosso states the field reports haven't been good for the CZ550 in 505 Gibbs. The latest CZ offering in this chamber has double cross bolts. So perhaps they have addressed some of the issues. I would strongly recommend that you make sure they allow you to practice feed some cartridges (a full magazine) prior to purchase. Do this practice feeding several times, operating the bolt fast, slow and intermediate.

I'm sure the action can bear up to that type of punishment buy why would you want to play around with 110 ftlbs of recoil. I personally dont think the stock is up to unless you have it heavily customised.

Mark

Thanks for the responses,

This purchase is really just intended to be a platform for a semi custom rifle. I’ll play with it for a while, and then I plan to have the gun sent away to a smith that has built quite a few 505s on the CZ 550. He said he can make it feed properly and slick up the action. I was planning on having an oversized bolt handle, three position safety, and some other additions. If the stock is not up to snuff I figured a McMillan would probably do nicely. I do not like the fact that the rifle only weighs around 10 pounds and do not want a muzzle brake. Hopefully a McMillan stock would add some weight and absorb some of that high recoil energy! I’ll probably shoot this load (600@2400) and realize I can’t recover from the recoil fast enough any way.

I have seen the bolt and the face is thin, but other posters here have said they never had a problem with this situation in other rifles. Has any one here had a problem with them? My smith says he has a fix for this.

I posted a while ago about converting my 416 RSM to 505 in an attempt at a relatively affordable 505. I mean affordable relative to my friends GMA 505 that he is having built. I should only have about half in a reworked CZ than he does in his GMA.

I do not have access to any pressure testing equipment and was just concerned about the ability of the CZ 550 to be able to handle 600@2400. I remember an older thread where someone said that Nickudu’s loads on the AR load data page were too much for the CZ550. Something to do with bolt thrust and the case head dimensions being so large on the Gibbs.

Does any one have any load data for 600@2400?

Thanks again, this is a great and interesting resource……

Matt V.

Nickudu used too fast a powder to obtain optimum (highest achievable) muzzle velocity. He did this in an attempt to reduce felt recoil. Powders for the 505 would be in the IMR4831 (or even IMR7828) burn rate. It will consume copious amounts of powder by the way.

If I remember I will look some data up, but my reloading notes are several hundred miles away and likely to stay that way for a while. A Square's manual "Any Shot You Want" has load data for the Gibbs (but I think it is all 525 gr). Perhaps one of the members with a copy handy can provide data to you from that source.

Trophyhunter,
My Safari classic in 505 Gibbs is currentlty on a diet of 570 gr GS custom FN at 2450 fps (127 gr H4831SC with 5 grain of filler) with no pressure signs. As for feeding, I did have to get my gunsmith to do a bit of tinkering to get the FN's to feed reliably (due to their flat nose), with the Barnes TSX's and woodleigh's I had no problems feeding. My gun also came with crossbolts and was bedded. As for recoil, I find it to be less than my Ruger in 416 Rigby.
The CZ is proably the best value for the dollar in an economy gun, and the wood on mine is quite exceptinal.

With their last price increase the cz 505 gibbs has become even less of a bargin. I think they're asking $2400 for them now. For a little more money you can get a WFF Hein that should address the cz 505 shortcomings. For a bit more than that you can get a AHR custom rifle in several bigbore calibers. I went with the Hein, which should be here soon.

I think the original concern about the 505 began because of the 3800 bar stamped on some receivers. That equates to 55,155 psi and you can't get a 600 gr bullet to 2500 without going to 61-62,000. No one seems to know what safety margin the 3800 bar represents and some are reluctant to push it.

Can't say I blame them but a lot of rounds over 55,115 are factory offerings like the Lott at 62,366. All the actions stamped 3800 bar that I have seen were originally 416 Rigby so maybe it is about bolt thrust and not absolute pressure.

Thanks for the clarification. That thread is why I questioned the CZ 550s ability to withstand my desired loading. I never even considered the use of too fast of a powder in such a large case. I have a copy of the A-Square and the Norma manual and they both list 525 grain bullets only.

I have never reloaded for a case larger than the 416 Rigby and have never used fillers. How do you use them?

The CZ 550s have definitely taken a price increase. I have a friend with a gun shop and he told me it would be cheaper to go to Cabela’s. I am going to try to negotiate with cash in hand. If they can’t work with me a little, then I agree it wouldn’t be much of a bargain. I never considered a Hein; do they have a larger bolt face than the CZ?

What pressures would be generated using IMR 4831 or 7828 to get 600@2400?

Thanks for the replies….

Matt V

quote:

Originally posted by Canuck32:
My Safari classic in 505 Gibbs is currentlty on a diet of 570 gr GS custom FN at 2450 fps (127 gr H4831SC with 5 grain of filler) with no pressure signs.

Cool.

You must be planning a return trip for some more DG, eh? That combo above will do some damage.

Where did you pick up your 505, if you don't mind me asking? I would guess a special order through Wholesale, but I haven't had a lot of luck going that route myself.

Cheers,
Canuck

I can't think why you would say a Hein is a little more. At $2450 for the CZ and $4,500 for the Hein, I think this is huge difference. $2,000 will buy another really nice rifle.

As far as proof marks and what they really mean, most 30-06 are proofed with 5 rounds a 90,000 lbs.or at least that is what Rich told me. As a major mfg of rifles including one that is chambered for the Lott, I can't believe that CZ would produce an action that wouldn't handle a 600gr bullet. Why you would want one to go out of the pipe in excess of 2,400fps escapes me but I am positive that your shoulder will break before the gun.
Dana

quote:

Originally posted by trophyhunter5000:
Thanks for the clarification. That thread is why I questioned the CZ 550s ability to withstand my desired loading. I never even considered the use of too fast of a powder in such a large case. I have a copy of the A-Square and the Norma manual and they both list 525 grain bullets only.

I have never reloaded for a case larger than the 416 Rigby and have never used fillers. How do you use them?

The CZ 550s have definitely taken a price increase. I have a friend with a gun shop and he told me it would be cheaper to go to Cabela’s. I am going to try to negotiate with cash in hand. If they can’t work with me a little, then I agree it wouldn’t be much of a bargain. I never considered a Hein; do they have a larger bolt face than the CZ?

What pressures would be generated using IMR 4831 or 7828 to get 600@2400?

Thanks for the replies….

Matt V

Quickload shows 59,300 psi with a Woodliegh 600 Weldcore over 133.0 gr IMR 4350. Velocity is 2496 and the charge is 103% of capacity so around that is your best range of powder burn rates. I use the 525 gr bullets and about 132 gr of Rel 19 to keep close to original specs. When I want more, I move up to the 550 Magnum and 700 Gr bullets. But to be honest, I seldom want that much more!

[QUOTE]Originally posted by Big Cabin:
I can't think why you would say a Hein is a little more. At $2450 for the CZ and $4,500 for the Hein, I think this is huge difference. $2,000 will buy another really nice rifle.

Price for the basic Hein is $2,700. The following is provided from the Hein web site:

The Palouse Trophy Series Rifle is designed and built with the hunting and shooting enthusiast in mind. At the heart of this rifle is our N-Series Action. Available in standard caliber from .17 Rem to .505 Gibbs, the combination or our N-Series Action, a hand bedded lightweight fiberglass stock and a match grade barrel is guaranteed to exceed all of your expectations.

Base Price: $2700.00

Standard Features:
- Custom Built Wff Hein N-Series Round Bridge Action
- Lightweight Hand Bedded Fiberglass Stock Color Black
- Custom Length of Pull (under 14.5")
- Custom Barrel Length (Under 28")
- Conventional or Straight Bolt Handle
- Match Grade Quality Barrel
- Fitted Scope Bases
- Bench Rest Quality Chambering
- Left or Right Handed
- Custom Serial Number

You can get the Hein with a .750 bolt. I'd figure a little over $3000 for the synthetic stocked Hein once you add a few niceties like sights.

Also wanted to mention that Hein will build them to take 4 down. I'm not sure what the CZ holds.

Unless they are using a Tardis for a magazine its probably 2 down.

quote:

Originally posted by tiggertate:
Unless they are using a Tardis for a magazine its probably 2 down.

Use full loads of slower ball powders or
slow Alliant powders and you can get 600gr
24-2500 at 40k psi or less.The Gibbs should
do nearly as good as my 510HE rimmed,
and it gets 500 fps more at 60k. So
pressures in Gibbs will not be high with
right powders.And cases will size easier
and last 50 rounds.Ed.

I have been load testing (with cast bullets) a friend's Wisner-built 505 Gibbs on a P17 Action. Eleven and one half pounds with a kick-eez pad. 120gr of Vihta Vuori Oy N160 and a 650gr gas-checked RFN gave me 2089fps at 40K psi according to the technicians at VVo. I shot five or six rounds a day (over a fifteen minute spread) from the bench and made 2" groups at 50 yards. I got up to 2275fps with N165 before deciding I did not like that recoil level. No, I am not telling you how much...but I would say that 125grains is tolerable. Rumor has it that the 505 Gibbs model CZ is barreled and reworked by McGowan for CZ, due to the small numbers, as is the 404 jeffery..and that is why they are twice the $$$. It would be worth a call to them to see if that is true and to inquire about cost and time. Our Cabelas's (Boise) has an american stock 416 for $799 asking price, and I was told it could be bought for $750.

Rich

Yes you can safely pusg a CZ550 to 2500 fps with a 600 gr bullet in 505 Gibbs. Like Ed Hubel suggests sure ball powder 760 or 748 will do the trick. I've proofed a CZ550 to better than 75 Kpsi and no changes in dimensions were noted.-Rob

Thank you all,

Your replies and clarifications have really helped! I am definitely going to go with the CZ. As far as my ability to withstand the recoil, well we’ll just have to see. I am going to order dies & brass today. I assume Jamison is they way to go for brass? Probably won’t get to work up any loads until after the holidays. I do have a few canisters of the slower Winchester & Alliant powders lying around.


Ed or Rob, would it be okay to email or pm either of you when I start loading? I would just need some guidance on starting loads etc….

Thanks again for all of the replies!

Matt V.

Anytime. The Gibbs is a nice cartridge and the Cz can be slicked up relatively easily. With most other .505 Gibbs guns in the 10K range, the Cz is a bargain.-Rob

quote:

Originally posted by trophyhunter5000:
I am sure this question has been asked before and I have tried to search the old postings. Please forgive my ineptness or laziness if I am beating a dead horse. Can the 505 Gibbs be loaded to fire a 600 grain bullet at 2400 fps in a CZ 550? In my research of old posts I saw that someone said trying to load the 505 to 2500 fps with a 600 grain bullet is crazy with anything short of a 50 BMG action.

I have convinced myself that I am going to purchase a CZ 550 Safari Classic in 505 Gibbs right after Christmas (I’ll have a bonus check that has got to go toward a new gun)!
I would like to be able to achieve the above ballistics (600@2400) in the said rifle.

I know I could do this easier/cheaper with a 500 A2, but would like to know if I could do it safely with the CZ 505 (I am currently waiting on to many custom jobs and would like to have something to shoot right away). Someone said the CZ is stamped 55KPSI; would this load be in that range? At what point would there be bolt thrust problems?

In summation;

1. Can the 505 Gibbs in the CZ 550 be safely loaded to launch a 600 grain bullet at 2400 fps (could some one please provide at least a starting load)?
2. If not, how fast can the 600 gain bullet be safely pushed in this rifle/cartridge combo?

The answers to this post will probably make my decision for me (on whether or not to buy the rifle). I am going to order dies this week, so please help me if I am about to waste some bucks!

Thanks for any responses…….

Matt V

Norma is right now producing the first "pre production cases" of the .505 Gibbs. they will load it with Woodleigh 600 grains bullets (Momentum is better than Energy).

Loaded ammunition and cases would be aviable in the US mid 2007.

Husky