Looking for input on cartridge choice to fit a standard action with a .473" bolt face. I'm trying to find the flattest shooting possible combined with very good retained energy (I know....who isn't) for longer range hits on antelope and deer.

I'm looking at things like the 280 AI, 6.5 Gibbs, 264 Hawk, or maybe a 6.5-280AI, etc. I know I can get something faster than a regular 6.5-284 or 6.5-06. I'm sure all these combinations have been done and I'm hoping someone here has had some experience with them. It's replacing a 25-06. I know it shoots plenty flat, but I'm looking for more downrange power. That rifle is for sale here, but if it doesn't sell I might be inclined to just rebarrel it with something like the above choices.

So, any thoughts on the most you can get out of this action with a 24" barrel would be great.

6mm-.270 IMP. Similar to 6mm Gibbs. 115 gr. bullet at 3000fps. 110 gr bullet at 3200 fps.
The one I owned was an out and out hammer of Thor on mule deer with the Barnes' original 110 and 115 grain bullets circa 1967. roger

I would build a 250 or 6.5 PDK but I already have the reamer

The various 270 & 280AI based wildcats will give you basically the same net capacity as the 06AI versions. Just a little longer neck. I happen to prefer a 257 or 6.5 bullet for longer ranges. But that is just me.

As bartsche said 6-270AI, 240Gibbs or the 240Wby will be prestty much the same. +/- a fps. I've always felt if you were going to try and maximize an 06 based case move the shoulder forward and blow it out. Like the Gibbs. I feel the 264hawk leave potential capcity on the table.

If your 25-06 has an accurate barrel and is at least 24" rent a 25 Gibbs reamer and go shooting.

SSK Industries has a line of '06 based wildcats with the ultimate in powder capacity: minimal taper, 60° shoulders, short necks, etc. These would be hard to top for velocity at distance in either the 6.5 or 7 mm.

I worried and pondered this for years. I just went through the calcs and execises again. When all is said and done, I think the 257 Weatherby is the king of the heap for this.

That said, I own several 243's, a couple of 6x284, two 240 Weatherby's, a couple of 25-06's, a 257 Weatherby, and several 7mm's including a 280 AI. In the real world, there is not a lot of difference in them. I suspect you are about as good to go as you will be with the 25-06 you have. There will be a couple of inches at 100 yds with some of them, but it will be be minimal.

quote:

I think the 257 Weatherby is the king of the heap for this.

Art,
If velocity and flat shooting is the desire the the 257Wby is VERY hard to beat. However in captains case he made two requests .473 bolt face and 24" barrel. I "feel" the Wby needs 26" min to start to shine not to mention mag bolt face.

Let see I'm shooting 284 on long action plus 280AI also have done the 30x280AI,6.5x284,6x284 and did a wildcat 338x270AI. I used a 280 case for the 338x270AI.

I know there some 6.5x280AI think Holland's gunsmith has reamers etc for that.

Lot depends on how much fire forming case you want to do. I have nothing against the 6.5 but if you look at the 7mm bullets all the way up to Berger and Matrix bullets for hunting be my choice.

My problem is I include elk if I'm looking at deer/antelope rifle since I get combination deer/elk tag here. My 6.5x284 was suppose to be my antelope rifle and was a great rifle but I always wind up taking one of deer/elk rifle.

Well, I pondered this over the weekend and I think the 6.5 Gibbs will be my best choice if I go with rebarreling. Assuming that it can drive a 140 gr bullet at 3100 or more fps, I will have a slightly flatter trajectory and at least 500 ft-lbs more energy at any given distance than my current 117 gr load in the 25-06. From what I have read, it should be capable of this. The flatter trajectory is a bonus. Even equaling the drop and adding energy would have been great for me.

This looks like an ideal hunting cartridge. It just carries much better than the 25-06:

Load Data
~~~~~~~~~
Name: .264 Cal, , 140 grn Hornady SST
Ballistic Coeff: 0.520
Bullet Weight: 140
Velocity: 3100
Target Distance: 200
Scope Height: 1.500
Temperature: 70
Altitude: 500

Ballistic Data
~~~~~~~~~~~~~~~
Range Elevation Velocity Energy ETA Drop Max Y 10mph Wind Deflect
0 yds -1.50 in 3100 fps 2987 fpe 0.000 sec 0.00 in -1.50 in 0.00 in
25 yds -0.45 in 3054 fps 2899 fpe 0.024 sec 0.11 in -0.57 in 0.02 in
50 yds 0.38 in 3009 fps 2814 fpe 0.049 sec 0.46 in -0.48 in 0.10 in
75 yds 0.96 in 2964 fps 2731 fpe 0.074 sec 1.04 in -0.33 in 0.26 in
100 yds 1.30 in 2920 fps 2650 fpe 0.099 sec 1.87 in -0.12 in 0.47 in
125 yds 1.38 in 2876 fps 2570 fpe 0.125 sec 2.95 in 0.16 in 0.76 in
150 yds 1.20 in 2832 fps 2493 fpe 0.152 sec 4.30 in 0.52 in 1.13 in
175 yds 0.74 in 2789 fps 2418 fpe 0.178 sec 5.93 in 0.95 in 1.58 in
200 yds 0.00 in 2747 fps 2345 fpe 0.206 sec 7.84 in 1.45 in 2.11 in
225 yds -1.03 in 2704 fps 2273 fpe 0.233 sec 10.03 in 2.04 in 2.71 in
250 yds -2.36 in 2662 fps 2203 fpe 0.261 sec 12.52 in 2.72 in 3.39 in
275 yds -3.98 in 2621 fps 2135 fpe 0.290 sec 15.32 in 3.48 in 4.13 in
300 yds -5.92 in 2580 fps 2069 fpe 0.318 sec 18.43 in 4.33 in 4.95 in
325 yds -8.18 in 2539 fps 2004 fpe 0.348 sec 21.85 in 5.27 in 5.82 in
350 yds -10.81 in 2499 fps 1941 fpe 0.378 sec 25.64 in 6.33 in 6.84 in
375 yds -13.71 in 2459 fps 1880 fpe 0.407 sec 29.71 in 7.47 in 7.84 in
400 yds -16.98 in 2419 fps 1819 fpe 0.438 sec 34.15 in 8.72 in 8.96 in
425 yds -20.64 in 2380 fps 1761 fpe 0.469 sec 38.98 in 10.10 in 10.19 in
450 yds -24.71 in 2341 fps 1704 fpe 0.501 sec 44.21 in 11.60 in 11.53 in
475 yds -29.18 in 2303 fps 1648 fpe 0.533 sec 49.85 in 13.23 in 12.98 in
500 yds -34.08 in 2265 fps 1594 fpe 0.566 sec 55.92 in 14.99 in 14.52 in
525 yds -39.41 in 2227 fps 1541 fpe 0.600 sec 62.41 in 16.89 in 16.18 in
550 yds -45.17 in 2189 fps 1490 fpe 0.634 sec 69.34 in 18.94 in 17.92 in
575 yds -51.38 in 2152 fps 1440 fpe 0.669 sec 76.72 in 21.14 in 19.77 in
600 yds -58.05 in 2116 fps 1391 fpe 0.704 sec 84.55 in 23.48 in 21.70 in
625 yds -65.17 in 2079 fps 1344 fpe 0.740 sec 92.85 in 25.99 in 23.73 in
650 yds -72.77 in 2043 fps 1297 fpe 0.776 sec 101.61 in 28.66 in 25.84 in
675 yds -80.84 in 2007 fps 1252 fpe 0.813 sec 110.84 in 31.49 in 28.04 in
700 yds -89.59 in 1972 fps 1209 fpe 0.850 sec 120.77 in 34.55 in 30.45 in
725 yds -98.64 in 1937 fps 1166 fpe 0.888 sec 130.98 in 37.73 in 32.82 in
750 yds -108.36 in 1902 fps 1124 fpe 0.927 sec 141.87 in 41.15 in 35.37 in
775 yds -118.77 in 1868 fps 1084 fpe 0.966 sec 153.45 in 44.80 in 38.10 in
800 yds -129.89 in 1834 fps 1046 fpe 1.007 sec 165.73 in 48.70 in 41.00 in


The necking, false shoulder, and fireforming aren't any more fiddly than was required when I shot a 338-06 AI, so this is all understood already. I borrowed this picture from an old post on another forum. If anyone objects, I will remove it...



The 257 Weatherby is a great choice, but I would just be better off buying a new Vanguard in this caliber than trying to do all the smithing needed on my action. Plus, as noted, I believe this needs at least a 26" barrel. The JDJ flavors of this have such a large steep shoulder, I imagine there will be feed issues. His cartridges are all optimized for single shots. There might be some tweaking needed with the Gibbs case, too, but I think it will be less than needed for the JDJ's.

If I end up buying a new rifle, I'm just going to go with a 300 Win Mag and be done with it for all the kinds of game I would usually shoot.

Thanks for the input!

You will be pushing to find a accuracy load at 3100 with a 140 in a 24" My guess more in the 3050 range. I would offer you my 6.5PDK dies but they were loaned out and the SOB moved and never responded. My pdk case is a 280 shoulder forward .46" dia shouder 40deg vs the 35 on the Gibbs. I love the 130gr accubond

I did look for a 6.5Gibbs reamer last year and couldn't find one to rent. Keep thinking about having a new reamer cut but other things keep getting in my way.

I'd have to go back in my notes to see if this Gibbs data was 24 or 26"

Thanks Paul. That's good info. It looks like the fine print at the bottom of the chart says 26" barrel.

Even if it only runs 3000 fps, I still have a gain in both trajectory and retained energy over the 25-06:

Load Data
~~~~~~~~~

Name: .264 Cal, , 140 grn
Ballistic Coeff: 0.520
Bullet Weight: 140
Velocity: 3000
Target Distance: 200
Scope Height: 1.500
Temperature: 70
Altitude: 500

Ballistic Data
~~~~~~~~~~~~~~~
Range Elevation Velocity Energy ETA Drop Max Y 10mph Wind Deflect
0 yds -1.50 in 3000 fps 2798 fpe 0.000 sec 0.00 in -1.50 in 0.00 in
25 yds -0.38 in 2955 fps 2715 fpe 0.025 sec 0.12 in -0.57 in 0.03 in
50 yds 0.49 in 2911 fps 2634 fpe 0.051 sec 0.49 in -0.48 in 0.12 in
75 yds 1.10 in 2867 fps 2555 fpe 0.077 sec 1.12 in -0.31 in 0.28 in
100 yds 1.45 in 2824 fps 2478 fpe 0.103 sec 2.01 in -0.08 in 0.53 in
125 yds 1.52 in 2781 fps 2404 fpe 0.130 sec 3.17 in 0.22 in 0.85 in
150 yds 1.31 in 2738 fps 2331 fpe 0.157 sec 4.62 in 0.60 in 1.25 in
175 yds 0.80 in 2696 fps 2259 fpe 0.185 sec 6.36 in 1.06 in 1.73 in
200 yds 0.00 in 2654 fps 2190 fpe 0.213 sec 8.40 in 1.60 in 2.27 in
225 yds -1.11 in 2613 fps 2122 fpe 0.241 sec 10.75 in 2.23 in 2.89 in
250 yds -2.53 in 2572 fps 2056 fpe 0.270 sec 13.41 in 2.95 in 3.57 in
275 yds -4.26 in 2531 fps 1992 fpe 0.300 sec 16.38 in 3.76 in 4.32 in
300 yds -6.37 in 2491 fps 1929 fpe 0.330 sec 19.73 in 4.68 in 5.21 in
325 yds -8.77 in 2451 fps 1868 fpe 0.360 sec 23.36 in 5.68 in 6.09 in
350 yds -11.54 in 2412 fps 1808 fpe 0.390 sec 27.37 in 6.80 in 7.08 in
375 yds -14.70 in 2372 fps 1749 fpe 0.422 sec 31.77 in 8.04 in 8.19 in
400 yds -18.26 in 2334 fps 1693 fpe 0.453 sec 36.57 in 9.39 in 9.41 in
425 yds -22.24 in 2295 fps 1637 fpe 0.486 sec 41.78 in 10.88 in 10.74 in
450 yds -26.63 in 2257 fps 1584 fpe 0.519 sec 47.41 in 12.50 in 12.17 in
475 yds -31.46 in 2219 fps 1531 fpe 0.553 sec 53.48 in 14.25 in 13.69 in
500 yds -36.73 in 2182 fps 1480 fpe 0.587 sec 59.98 in 16.15 in 15.32 in
525 yds -42.44 in 2145 fps 1430 fpe 0.622 sec 66.94 in 18.19 in 17.04 in
550 yds -48.62 in 2108 fps 1382 fpe 0.657 sec 74.35 in 20.38 in 18.85 in
575 yds -55.25 in 2072 fps 1335 fpe 0.693 sec 82.23 in 22.73 in 20.75 in
600 yds -62.36 in 2036 fps 1288 fpe 0.729 sec 90.57 in 25.24 in 22.74 in

This is still a winner for me. I don't know how old your data is. We may have some powder that will help in this case. For example, using Retumbo in the 25-06 helps it quite a bit. I would assume that our slower powders today would work well in the 6.5 Gibbs too.

That was my point about the 257 WM. I bought a closeout Vanguard (old model) at Sportsman's Warehouse not long ago for about the price of a new barrel blank, and it shoots 1/2" groups all day. I also agree that a 300 Win or Weatherby magnum would fill the bill. Wildcats are fun (I own a bunch) but they are really just expensive toys in today's market. You have to really look to find any kind of niche, given all the botique guns and calibers which now exist.

The discussion about the Gibb's cartridges is illustrative of what keeps wildcats going. The data of these look great, and they are generally safe, but no manufacturer has ever loaded ammo to the level these are normally loaded. There is nothing magic about interior ballistics, and a cartridge of one bore diameter and throating with a given case volume will give the same performance as another with the same parameters. Some faets of cartridge design may be slightly more consistent and produce better accuracy on the average, but it takes a full bench rest approach to realize it.

I suspect that if you stuffed enough powder in you 25-06 to run it at the same pressure as the Gibb's cartridges have always been loaded and used the same length barrel, you would wonder if a rebarrel/rechamber is worth it.

quote:

The data of these look great, and they are generally safe, but no manufacturer has ever loaded ammo to the level these are normally loaded. There is nothing magic about interior ballistics, and a cartridge of one bore diameter and throating with a given case volume will give the same performance as another with the same parameters. Some faets of cartridge design may be slightly more consistent and produce better accuracy on the average, but it takes a full bench rest approach to realize it.

Some are also more efficient. At equal pressure normally capacity wins. I shoot my own PDKs kind of a Gibbs+ I've found I can match the normal factory magnum of the same caliber. Normally my hand loaded magnums win out. I normally try and load in the 63-65,000 range. If I can't get 6-7 reloads plus the forming load then I deem it to hot.

Looking at the Gibbs data I stole from the article it doesn't look too me like the load number are correct. Other max loads in the article for the 270Gibbs & 7mmGibbs calculate in the 65-70,000psi range and really darn close to the claimed velocity. The 6.5 data looks strange. Velocities too high and calculated pressure too low.

Only thing a Gibbs will do vs say the 264Wmag is burn a touch less powder and do it with a .473 bolt face. But don't listen to me I love to be different.

Last thought good luck finding a 6.5Gibbs reamer to rent. 270Gibbs no issue.

If you calculate ballistics for a 6.5x284 with a Berger 140 vld bullet at 3000fps. The drop is 58 inches with a 100yard zero versus your 62 with a 200 yard zero at 600yards. The velocity is 2500 versus 2000 fps. Energy is 2000 versus 1288. Bergers nock elk dead. Its a no brainer to me for a 6.5x284 Norma Match and a 26 inch tube. But hey thats just me.

7x64

I have a 257Imp at my gunsmiths for sale,,if it is still there after I'm done in Bristol Bay it's going to get a 6.5 Gibbs barrel! Maybe mid-season if things are going good.

Isn't the 7x64 basically a 280 Rem? They are pretty close from what I understand.

I've been looking a bit more and the 25 Gibbs might not be a bad idea. I was looking for more bullet weight so the 6.5 and 7mm options are more attractive, but the 25 Gibbs does add lots of speed to the 117 and 120 gr .257 loads. The bigger bullets just carry more energy for more distance. We'll have to see if the 25-06 sells...

quote:

Originally posted by waterrat:
I have a 257Imp at my gunsmiths for sale,,if it is still there after I'm done in Bristol Bay it's going to get a 6.5 Gibbs barrel! Maybe mid-season if things are going good.

waterrat - definitely get back to us if you go with the 6.5 Gibbs! I'd love to hear how it works out.

quote:

Originally posted by the_captain:
Isn't the 7x64 basically a 280 Rem? They are pretty close from what I understand.

yes, the 280 rem is basically a 7x64 . FIFTY years after the 7x64, but larger case capacity and faster twist that allows for using higher BC/longer bullets

and its way cool

Without going through the hassle of reading a bunch of ballistic tables,I think the OP would be hard pressed to beat a 280AI with something like a 162 Amax,or 150 Swift SS II,and maybe others.

If it does get beat,it will be by fractions likely undiscernable afield.For the game mentioned,I can't think of anything much better on a .473 bolt face.

My choice for a new build is the 284 Win.

I sure don't want to rain on anyones parade. If a guy wants a new rifle and/or wildcat then he should go for it. Just running some of the number from loads I have in the 257-284 range. I have a 24" 25-06, had both a 250 & 6.5 PDK Gibbs design plus a few grains and a 280PDK. Using 130& 140s in the 6.5 115 silver tips in the 25-06 and 150 in the 280. MY point blank ranges varied from 343 to 352 yds 25-06 the high 280 the low. 400yd energy 1844 down to 1646. 280 the high and the 130 6.5 the low.

I've shot a lot and I can't see the difference in a 9yd point blank range difference and the animal won't feel the 11% difference in energy.

Heck with some of the velocties the guys are reading in their 338-06 with RL 17 maybe that is the way to go.

Seriously. In all the suggested option you won't get enough difference to worry about. So build what you want to shoot.

I'd be happy to share some of my 6.5PDK as well as others 6.5gibbs results if interested PM me.

Just sent in a action for rebarreling this weekend. 264 Win Mag it is.

quote:

Just sent in a action for rebarreling this weekend. 264 Win Mag it is

Man I hate that I have 264Wmag dies and brass and no rifle. One of these days I'll get around to it.

Gents any reason nobody has mention the RUM's isnt this what they were designed for ?

reg S&F

Well, in my particular case, I need something to fit a standard length action with a .473" bolt face. The RUMs are too long and too wide for this action. Other than that, a 300 RUM or 7mm RUM would really be a long range whacker.

A 6.5-284 was going to be my input.

Or a 6-284. 115 Bergers at 3300 fps shoot mighty flat and will kill deer more than fine.

6.5 X 54 M/S 160G. was always my favorite.A classic cal. + be sides;check your ballistics,has the most SD + bore per calibre in that grain,even though we do not get super velocity.Yeah,yeah,the 7x57 is still my queen.I'm sorry Tyler;got off the subject. Build a 30/416 AI.your best results per our author.....A bit of feed back from Ross.More in the next couple of days.(Tyler,you can form your brass by by using .416 Rigby cases.Your call.