A friend let me borrow a CD that he got with a subscription to Handloader magazine. Had a large PDF file on Rocky Gibbs and his wildcats. The .270 Gibbs sure intrests me!

Shortly after that I was talking with Kevin Weaver because I know he has a .25 Gibbs rifle. He said with a 26" barrel and powders like Retumbo and RL22 and some other newer ones they live up to what Rocky Gibbs said they would.

So is anyone out there using a rifle chambered in one of Rocky's cartridges? How do you like it? Plus I have a VZ-24 that needs a barrel.

I have my own wildcat series. At the time I had never heard of Rocky Gibbs. My case is a 280 not 06 and I used a 40 deg vs Rocky's 35. I end up with about 2grs more gross capacity. Here is a comparison of the various options in 338 I dont' ahve a 270 but the shoulder location is the same.

I have not trouble getting his velocity as long as I adjust for barrel length. Remember Rocky measured barrel from the end of the bullet not the bolt face. Another option is the 270 Howell. Brass and dies available from AHR.

I have a 240 and 6.5 Gibbs, with 26" & 27" barrels. Suprisingly, the 240 is one of the most accurate hunting rifles I own, and will consistanly shoot 3/8's groups with 95 grn noslers and H870 @3400 fps. The 6.5 has a Lilja barrel and is so fast with 120's and Re 22 it's scary.

I have a 30 Gibbs, chambered from an '06 by Dennis Olsen of Plains, MT. I haven't shot it yet.

quote:

The 6.5 has

I had a 6.5 PDK it would match my buddies 264 Wmag. Actually beat it on accuracy loads. Never did a 270 but love the 6.5 & 7mm.

I had a .270 Gibbs built because a friend had a book about Rocky Gibbs and I found it to be very interesting. The .270 was Rocky's favorite. I already had two .270's, an old Sako Finnbear and a fairly new Browning A-Bolt. I had a gunsmith convert the Browning to .270 Gibbs using a 26" Pacnor barrel. I sent Clymer some .270 cases with 150gr Nosler Partitions seated out as far as they would go (and still fit in the magazine) and had them build a reamer. I ordered a full length resize die set from RCBS. After I had fireformed a few cases I sent the die back to RCBS and had them polish out the die to fit the fired cases. The only problem I had was that I had to modify the magazine so it would feed. This is the most accurate deer rifle I've owned so far. I use 150gr Hornady SST's for fireforming and it shoots cloverleafs. With the 150gr Nosler Partitions I've never had a group larger that .4" @ 100 yards. I think a good shot could do better. I have a new cronograph I haven't used yet but I plan to soon. Right now I'm shooting 61gr of H4831 with no problem and there's a lot of room still left in the case. I want to try different powders and I'm open to suggestions. Fire forming is a lot of extra work and breaking in barrels isn't one of my favorite things to do. I like this rifle but I don't think I'll do anymore wildcats.

I have lots of Gibbs data and Info on "paper" and will fax it to you if you like.

Send me a PM with fax number.

My cents worth...FWIW...been doing wildcats for 40 odd years and I'm working on my LAST one right now just to have my own named 50 cal cartridge.

I agree with Silverado...EVERYTHING you do concerning wildcatting usually involves lots of extra work and in todays world there are cases that don't require much more than necking up or down, that are already optimized as far as case capacity, shoulder angle, case taper and so on...and factory rifles available so you DON'T have to mess with feeding problems...AND many of those cases have ALREADY been wildcatted up and down as far as they will go.

Why bother with reinventing the wheel over and over again...

The only area that was open...the really BIG BORES is quickly being filled as we speak.

I think everyone who is a gun lover should have at least ONE wildcat and should go through the process just for the learning...but do the learning by looking over someone's shoulder and let THEM have the headaches... hahahahahahaha

quote:

I agree with Silverado...EVERYTHING you do concerning wildcatting usually involves lots of extra work and in todays world there are cases that don't require much more than necking up or down, that are already optimized as far as case capacity, shoulder angle, case taper and so on...and factory rifles available so you DON'T have to mess with feeding problems...AND many of those cases have ALREADY been wildcatted up and down as far as they will go.

I agree pretty much. I built my first one becasue I believed on all the press. Then got real world results. A good wildcat will get you close to the next larger magnum factory. Can they do anything that you can't get a factory chambering to do? Only in limited cases. Yep My 6.5PDK, 280PDK and 340PDK allow me to pretty much match factory 264, 7mag and 338wmag factory and if I give my self 2" of barrel I can match my own handloads for the magnums.
My 400PDK does allow me to equal and beat facotry 450-400s and 404J. Using a lot less powder and recoil.

I simply do it for fun. Are factory rds easier yep.
If you want a Gibbs go for it. It is fun and a great campfire discussion. If you simply want higher 270 velocities simply get a 270Wby.

As I said earlier a cheap option is the Howell series from AHR. Brass, dies and loaded ammo available. Case capacities equal to or great than the Gibbs.

quote:

Originally posted by Terry Blauwkamp:
I have lots of Gibbs data and Info on "paper" and will fax it to you if you like.

Send me a PM with fax number.

Don't have a fax but I'll see about the one at work. Just depends on how much info you have. The boss kind of frowns on us if we burn excessive amounts of paper for personal use.

Don't know if I'll do the Gibb's cartridge or not. My other options are the .375 and .400 Whelen. I love reading about wildcats and the guys who made them back in the day, especially if there is a little mystery to them. The story of Rocky Gibbs and his wildcats was just very enjoyable to read and think on. There are a lot of cartridges that catch my eye and start me daydreaming!

Silverado, I would love to hear about your findings when you run some full power loads across the chrony. .4" is pretty impressive with fire forming loads even if they aren't full pressure loads. I hope you enjoy the rifle. Are you having problems with split cases during fire forming?

Thanks for all the info so far guys!

quote:

Don't know if I'll do the Gibb's cartridge or not. My other options are the .375 and .400 Whelen.

I've scanned the Gibbs articles and can email them to you. All or only the calibers you ae interested in.

The 400 Whelen would be a keeper. I've been playing with my 400PDK. Whelen on steriods. Almost 2400 with a 400gr nice and easy 2257 accuracy load. Do a search I've posted my results. A 375 version is waiting for serious testing as I type. A 411 Hawk or Z-hats .411 Express would be options as well.

I had a couple of split cases at first. They were splitting at the shoulder. I was using the small shoulder created when you neck down from .30 to .270. I formed the shoulder long so it was hard to close the bolt. Someone suggested I seat the bullets out until they were firmly into the lands. Since I started seating the bullets long also I haven't had any more spilt cases. I'm using Winchester brass and 57gr of H4831 which is about a max load for a .270 Winchester with 150gr bullets. The cases are fully formed after one shot. I could hunt with these fireform loads but it would be a single shot because they're too long to fit in the magazine. Some guy on reloadersnest.com says he's getting 3423fps with 150gr bullets out of a 24" barrel using 66gr of IMR4831. I'm pretty sure I'm not even close to that and I don't know if that's a safe load.

quote:

Some guy on reloadersnest.com says he's getting 3423fps with 150gr bullets out of a 24" barrel using 66gr of IMR4831

Well anyone can claim anything. But he must be smoking dope.

QL calls 66 gr of IMR 4831 in a 24" as 114% capacity 3340fps and 99929 PSI Matter of fact that load is still 78829 if loaded in a 270Wby

Your load is called 2952 @ 62000

quote:

Originally posted by ramrod340:

quote:

Don't know if I'll do the Gibb's cartridge or not. My other options are the .375 and .400 Whelen.

I've scanned the Gibbs articles and can email them to you. All or only the calibers you ae interested in.

I'll take any and all info that I can get. I'd even like to hear about your PDK cartridges. Email: taylorce1@yahoo.com

Silverado if you are getting 2900+ fps with 150 grain bullets that is pretty good IMO. I was reading on Kevin's web site about having split neck problems. I was wondering if annealing wouldn't solve a lot of the problems?

I ran into quite a few split necks when trying to fire form .405 win cases into .280 GNR cartridges. My first venture into wildcatting was a dismal failure and I hated that barrel for my Encore pistol. Traded off the barrel and now need to fire form some .375 JDJ cartridges.

I'd love to get my hands on one of the old .270 Gibbs Hydraulic form dies! Of course it would have to be cheap. Trying to pay for other stuff this year and don't have much to spend on my firearms.

Terry why don't you make photocopies and mail them to me, I can convert them to PDF and JPEG.

quote:

Originally posted by Terry Blauwkamp:
I have lots of Gibbs data and Info on "paper" and will fax it to you if you like.

Send me a PM with fax number.

quote:

I'll take any and all info that I can get. I'd even like to hear about your PDK cartridges. Email

Emails have been sent. As to PDK data simply do a search here on AR and you can most of my info.

quote:

Originally posted by ramrod340:

quote:

I'll take any and all info that I can get. I'd even like to hear about your PDK cartridges. Email

Emails have been sent. As to PDK data simply do a search here on AR and you can most of my info.

Thanks for the info, really appreciate it.

Remember that Rocky Gibbs measured barrel length by the distance the bullet traveled.....so his 26" barrel was actually any one elses 28.5" barrel

quote:

his 26" barrel was actually any one elses 28.5" barrel

Actually closer to 29.34" . Just like vapodog stated you have to really pay attention to the data you are reading for the various Gibbs. I've seen Gibbs data per Rocky's measuremnts in early Rocky documents. It was my understanding that the series of articles writen by someone else after Rocky's death and later printed into a small book used the normal barrel length measurement. Last but not least he would adjust the velocity back to muzzel velocity as well as take the highest of a 10 shot string not the average. Everything to his favor. He did use pressure barrels and limited his loads to 53,000 CUP saying even the strongest brass would start expand the pocket at those levels. Since his favorite was the 270 as an example the limits for it are 52,000CUP and 65,000PSI. So basically he loaded to 270 pressures.

As to the later articles published on the Gibbs line most referenced a 26" barrel. On the calibers I've made my PDKs this data matchs very well to my measurements adjusted for any length difference to the 26". My case has about 2grs more gross capacity but darn close net. Also QL data matches closer on a 26" than a 29+.

Well I finally have my 7 mm Gibbs up and going. Been messign with it for a month now. 1st i had to make brass so I started by neck ing down 30-06 to 7mm Gibbs and loading 13grs of Bullseye and cornmeal stuffed with papertowel topped off with candle wax. Only one case was split at the neck. I'm up to 70 cases now. Started load developement with the fireformed cases. it likes H-4831. Went out today to try some mor eloads 1st load was 60.5gr of H-4831 with a 160gr Speer Hot core w/cci 250. Temps were around 22-24 degrees. No pressure next load same billet and primer was 61.0grs no pressures yet last load I tried was 61.5 grs shot fine no signes of pressure yet. Bolt easy to lift primers looked good. Some of the cases are on thier 3rd firing. The rifle a 1909 Argentine with a 26 douglas barrel. I do not own a chronograph so I have no idea what the velocities are... So if some one could run the last load of 61.5 gr H-4831 into quick load that would be great. As of now I think I will stop at 61.5gr of H-4831.

quote:

Originally posted by 323:
Well I finally have my 7 mm Gibbs up and going. Been messign with it for a month now. 1st i had to make brass so I started by neck ing down 30-06 to 7mm Gibbs and loading 13grs of Bullseye and cornmeal stuffed with papertowel topped off with candle wax. Only one case was split at the neck. I'm up to 70 cases now. Started load developement with the fireformed cases. it likes H-4831. Went out today to try some mor eloads 1st load was 60.5gr of H-4831 with a 160gr Speer Hot core w/cci 250. Temps were around 22-24 degrees. No pressure next load same billet and primer was 61.0grs no pressures yet last load I tried was 61.5 grs shot fine no signes of pressure yet. Bolt easy to lift primers looked good. Some of the cases are on thier 3rd firing. The rifle a 1909 Argentine with a 26 douglas barrel. I do not own a chronograph so I have no idea what the velocities are... So if some one could run the last load of 61.5 gr H-4831 into quick load that would be great. As of now I think I will stop at 61.5gr of H-4831.

So how does it group?

Well that is another story it is throwing flyers due to bedding issues. Would be working on 1 inch groups and wham flyers open her up... Also another thing it does not like a clean barrel. Anyhow I worked on the bedding today and will take it out again. Even with the flyers it shows potential. With this load, It has had me scratching my head. But I have it figured out and like I said the next go around will hopefully produce better groups. I can hoenstly say I cna probably keep going with the powder increase but like I said will stop at 61.5 for now. I need to get a chronograph.

323-- give me your case capacity and OAL and Ill run QL for you

Thanks my OAL is 3.375 and case capacity I used water and it holds 71.0gr of water in the case. I hope that is what you needed to figure it out. Thanks

Cartridge : 7 mm Gibbs
Bullet : .284, 160, Speer SP 1635
Useable Case Capaci: 64.964 grain H2O = 4.218 cm³
Cartridge O.A.L. L6: 3.375 inch = 85.73 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon H4831

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-10.0 95 55.35 2688 2566 44617 9891 94.8 1.412
-09.0 96 55.97 2718 2625 46146 10007 95.3 1.390
-08.0 97 56.58 2748 2684 47730 10120 95.7 1.368
-07.0 98 57.20 2779 2743 49371 10229 96.2 1.348
-06.0 99 57.81 2809 2804 51072 10335 96.6 1.327
-05.0 100 58.43 2840 2865 52840 10437 97.0 1.307
-04.0 101 59.04 2870 2927 54675 10535 97.3 1.287 ! Near Maximum !
-03.0 103 59.66 2901 2989 56577 10629 97.7 1.267 ! Near Maximum !
-02.0 104 60.27 2931 3052 58549 10719 98.0 1.248 ! Near Maximum !
-01.0 105 60.89 2961 3116 60588 10805 98.3 1.229 ! Near Maximum !
+00.0 106 61.50 2992 3180 62698 10887 98.6 1.210 !DANGEROUS LOAD-DO NOT USE!
+01.0 107 62.12 3022 3245 64886 10964 98.8 1.192 !DANGEROUS LOAD-DO NOT USE!
+02.0 108 62.73 3052 3310 67158 11037 99.0 1.174 !DANGEROUS LOAD-DO NOT USE!
+03.0 109 63.35 3083 3376 69517 11105 99.2 1.156 !DANGEROUS LOAD-DO NOT USE!
+04.0 110 63.96 3113 3443 71969 11168 99.4 1.139 !DANGEROUS LOAD-DO NOT USE!
+05.0 111 64.58 3143 3510 74517 11226 99.6 1.122 !DANGEROUS LOAD-DO NOT USE!

Wow I better back offand stick with 60.5gr of H-4831. How accurate is QL? As I siad before the 61.5gr was shwoing now pressure ie nto flattened primers and stick bolt lift. Anyhow for now going to stick with 60.5 don't want to get into toruble with 61.5grs... Thanks again.

I've found QL to be fairly accurate. AFTER it is adjusted for my specific powders burn rate. This is they disclaimer they have on the bottom of the data.

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 106 61.50 3123 3466 74755 10629 100.0 1.125 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 106 61.50 2812 2810 51143 10597 92.9 1.321

This info is a pure calculation based on the "NORMAL" powder burn rate. That can very up or down. So your pressure could be up or down from the data above. What It says and I have found very accurate is to adjust the burn rate for your powder. I've found is if I take a known charge and velocity then adjust the burnrate up or down usually 2-3% I can get QL to match my actual results. Then when I use that burn rate for that powder in the same case or others the results are REAL darn close to actual measured.

QL has the max pressure for the Gibbs as 58740. Why? I have no clue. I elected to set it at 63,000 that is why your load read dangerous. If I set it to 65,000 to match a 25-06 or 270 then it only reads near max.

This data is only 1 more data point. You are showing no pressure we don't know the velocity and your cases are not showing a head expansion. I would shoot the load if it is accurate. If your velocity is what you want and your are getting 5+ reloads leave it as is and enjoy.

Thanks... I primed the cases last night and still tight primer pockets... I have always went off of sticky bolt or stuck bolt LOL and flattend primers for high pressure but I know neither one of those can occur and still have dangerous pressures... But the 61.5grs does shoot good even with the beddign issues. I need to load some more up and o to the range and see how it does now that I have the bedding issue fixed.