Is there a 130gr bullet in .257 cal

[Paul Kronhardt]

Paul, In 2005 I began experimenting with the heavy 125, 130, 142 and 156 grain Wildcat bullets. I worked up and chronographed loads with those in my existing custom 25/06 AI, (Sako L61action, Shilen 24 inch 10 twist barrel) to see what velocities were achievable, although I knew that they would not stabilise. My chrono results were:

Note that AR 2217 is rebadged as H1000 in US, and AR 2225 is rebadged as H Retumbo in US.

Nosler 115 BT
61.0 Hodgdon 1000 3157 Normal Pressure,
62.0 " 3192 Near Maximum Pressure,
63.0 " 3271 Max Pressure, 99% loading density

61.0 Alliant Reloader 25 3218
62.0 " 3293 Max Pressure, about 98% loading density.

62.0 Vihtavouri N170 3165 Mild Pressure,
63.0 " 3202 Normal Pressure
64.0 " 3286 Near Max Pressure, slightly compressed load

Wildcat 125 grain ULD
58.0 ADI AR 2217 2961 Pressure Mild
59.0 " 2998 Pressure Normal
60.0 " 3105 Pressure Max. about 95% loading density

60.0 Alliant Reloader 25 3129 Pressure Normal
61.0 " 3183 Pressure Max about 98% load density

61.0 ADI AR 2225 3039 Pressure Mild
62.0 " " 3058 Pressure Mild
63.0 " " 3102 Pressure Near Max about 98% loading density

62.0 Vihtavouri N170 3019 Pressure Mild
63.0 " " 3103 Pressure Mild
64.0 " " 3139 Pressure Near Max, about 100% loading density

65.0 Hodgdon 870 3006 Pressure Mild
66.0 " " 3061 Pressure Mild, about 100% loading density
Note: The 10 twist struggled to stabilise this bullet.

Wildcat 130 grain Bonded Core Flat Base HP.
58.0 ADI AR2217 2960
59.0 " 2982
60.0 " 3019 Maximum Pressure, about 97% loading density.

58.0 Alliant Reloader 25 2978
59.0 " 3036
60.0 " 3091
61.0 " 3158 Maximum Pressure, about 99% loading density

58.0 Vihtavouri N170 2861
59.0 " 2855
60.0 " 2925
61.0 " 2969 Near Max Pressure, about 99% loading density.

65.0 Hodgdon 870 3038 Maximum Pressure, about 985 loading density

Note: Excellent accuracy was achieved with this bullet in the 1 in 10 twist barrel.


Wildcat 142 grain ULD
57.0 Alliant Reloader 25 2927 Normal Pressure
58.0 " 3011 Near Maximum Pressure
59.0 " 3042 Maximum Pressure, about 95% loading density.

60.0 ADI AR 2225 2914 Normal Pressure
61.0 " 2986 Near Maximum Pressure,
62.0 " 3039 Maximum Pressure, about 100% loading density

61.0 Vihtavouri N170 2928 Normal pressure
62.0 " 3020 Near Maximum Pressure
63.0 " 3096 Maximum Pressure, slightly compressed load

64.0 Hodgdon 870 2953 Near Maximum Pressure
65.0 " 3018 Maximum Pressure, about 99% loading density

Note: The 1 in 10 twist barrel did not stabilise the bullets, and all shots key-holed into the 100 yard target.

Wildcat 156 grain ULD
57.0 ADI AR 2225 2782 Near Maximum Pressure
58.0 " 2810 Maximum Pressure, about 95% loading density.

57.0 Vihtavouri N170 2700 Normal pressure
58.0 " 2773 Near Maximum Pressure
59.0 " 2820 Maximum Pressure, about 97% loading density.

60.0 Hodgdon 870 2705 Normal Pressure
61.0 " 2725 "
62.0 " 2771 Near Maximum Pressure
63.0 " 2832 Maximum Pressure, about 99% loading density

Note: The 1 in 10 twist barrel did not stabilise the bullets, and all shots key-holed into the 100 yard target.

On the basis of these results I built up a custom 257 Weatherby (no freebore), using Rem 700 action, and Krieger 26 inch 7 twist barrel. My chrono results using Norma 257W cases and Federal 215 primers were:

Nosler 115 grain BT
76.0 Hodgdon 870 3210
77.0 Hodgdon 870 3319
78.0 Hodgdon 870 3338 Maximum Pressure

77.0 ADI AR 2218 3150
78.0 ADI AR 2218 3237
79.0 ADI AR 2218 3291 Near Maximum Pressure

Wildcat 125 grain ULD
74.0 Hodgdon 870 3132
75.0 Hodgdon 870 3201
76.0 Hodgdon 870 3215 Pressure Maximum

Wildcat 130 grain Bonded Core Flat Base HP
73.0 ADI AR 2218 3120 Mild Pressure
74.0 ADI AR 2218 3151
75.0 ADI AR 2218 3182 Near Maximum Pressure

Wildcat 142 grain ULD
70.0 ADI AR 2218 3050
71.0 ADI AR 2218 3069
72.0 ADI AR 2218 3119 Near Maximum Pressure

69.0 Hodgdon 870 3092
70.0 Hodgdon 870 3110
71.0 Hodgdon 870 3150 Maximum Pressure

Note: Some of the projectiles would not reach 100 yard target, in some instances just fragments would reach, and several others reached intact. It appears that the 7 twist barrel and the 310,000 – 320,000 rpm generated at 3,000 – 3150 fps, are too much for the Wildcat 142 ULD.

Wildcat 156 grain ULD
63.0 ADI AR 2225 2783
64.0 ADI AR 2225 2831 Max Pressure
65.0 ADI AR 2225 2855 Above Max/Maximum Pressure?

63.0 Vihtavouri N170 2791
64.0 Vihtavouri N170 2841 Maximum Pressure

65.0 Hodgdon 870 2693
66.0 Hodgdon 870 2776
67.0 Hodgdon 870 2818
68.0 Hodgdon 870 2849
69.0 Hodgdon 870 2881 Maximum Pressure

66.0 ADI AR 2218 2678
67.0 ADI AR 2218 2743
68.0 ADI AR 2218 2776
69.0 ADI AR 2218 2831
70.0 ADI AR 2218 2872 Maximum Pressure

70.0 Vihtavouri 20N29 3026 Pierced primer, above Maximum Pressure due to powder bridging

Note: Excellent accuracy was achieved with this bullet.

On the suspicion that the Norma 257W brass was a soft, I formed some cases using Remington 300Winchester Magnum cases. (capacity about 3.8 grains less than 257W cases)

Wildcat 156 grain ULD
67.0 ADI AR 2218 2842
68.0 ADI AR 2218 2926
69.0 ADI AR 2218 2962 Pressure Maximum

Unfortunately I was not able to do further testing, as the 257W, 25/06 AI, and the Wildcat bullets were stolen in 2009.

Hope that the above is of some interest. Brian

Thank you very much Brian looks very interesting. do you think we will ever get Wildcat Bullets back. And if you remember off the top of your head what were the ballistic coefficients of them wildcats for 25 cal

 

[brianwinzor]

Paul, I am in the dark as to whether Wildcat bullets will be available again, and I just noticed that their website is still under development.

Richard Graves the original owner of Wildcat bullets never had the time to do any specific testing to ascertain the ballistic coefficient of his bullets.

I remember Kirby Allen after performing drop tests at various ranges, estimated that the bc of the 257 cal 156 grain uld was about .810. I only tried this bullet on a target out to 450 yards, and didn't perform a similar test, but this bullet when fired in my 257 Weatherby was definitely the best performer in the wind that I have ever used in the field. This bullet is 1.545 inches in length, so a bc of .750 and above would not surprise me.

I have listed the lengths of the various 257 cal bullets that I used to give you a comparison.

100 grain Nosler BT - 1.115 inches
115 grain Nosler BT - 1.204 inches
125 grain Wildcat Uld- 1.268 inches
130 grain Wildcat BCFBHP - 1.220 inches
142 grain Wildcat ULD - 1.365 inches
156 grain Wildcat ULD - 1.545 inches.

What did I learn from my .257 Weatherby with 7 twist barrel experiment?
(1) If heavy bullets of similar weight (125 - 156 grains) became available again, I doubt whether I would use the .257 Weatherby case, especially if I was plannning to mainly use the 156 grain bullet for my field loads.

The main problem with the 257W case is that there are not any powders slow enough currently available when using the 156 grain bullet to give the loading density that I prefer. (at least 90%) A maximum load of 69.0 grains of H870 with this bullet only achieves a load density of 81%, which leaves a lot of air space in a large case.

The comparison with 25/06AI highlights the difference when using the 156 grain bullet.
The 257 W with a 26 inch barrel used 69 grains H870 to produce 2,881 fps (load density 81%)
The 25/06AI with 24 inch barrel used 63 grains H870 to produce 2,832 fps (load density close to 100%.

If the 25/06 AI had a 26 inch barrel the velocity difference would be neglible. So next time I would either use this case or look at using a slightly larger case with the a capacity of about 75 - 80 grains.

(2) I also learnt that the 7 twist barrel needed to stabilise the long 156 grain bullet, put too much stress on the Wildcat 125 and 142 grain ULDs, and their j4 jackets where shredded causing the bullets to fragment. Consequently, these 125 and 142 bullets probably could only be used in a 8 or 9 twist barrel

Surprisingly, both the 100 and 115 grain Nosler Ballistic Tips withstood the incredible rotational stress and held together when fired in the 7 twist barrel. They must be very stout bullets.

Overall, I believe the testing confirmed that if heavier bullets with the appropriate construction in the 125 - 150 grain range were available again, then the 257 calibre could easily become a viable long range alternative.

Hope the above is of some help. Brian

 

[Lefty7mmstw]

The main problem with the 257W case is that there are not any powders slow enough currently available when using the 156 grain bullet to give the loading density that I prefer. (at least 90%) A maximum load of 69.0 grains of H870 with this bullet only achieves a load density of 81%, which leaves a lot of air space in a large case.

If you use a 50bmg stick powder your load density will be a lot better. We've had good luck with rl50 and I 5010 in 7 ultra's and 300 ultra's with heavy pills. Very high velocities and good(sometimes slightly too good and rather compressed) loading density. I'm liking rl50 quite a bit lately with 225's in my 300 ultra. My I 5010 became fertilizer last year as it went bad.

 

[brianwinzor]

I used AR 2218 (H50BMG in US) and Viht 20N29 (both stick powders) with the 156 grain ULD in my 257W with vastly different results.

A maximum load of 70.0 grains AR 2218 produced 2872 fps and a loading density of 85%, which was a little better than the 81% with H870, but still way under what I prefer. This load gave excellent accuracy, and I used it successfuly for about 300 shots as my field load with the 156 grain bullet.

I acquired some Viht 20N29 (long cut extruded powder) as research seemed to indicate that its burning rate was a little slower that AR 2218. However, in my 257W, it produced my first experience with "powder bridging", as a 70.0 grain load, and then after unloading the rest, and then reloading a 67.0 grain load, it also produced a pierced primer.

Subsequent testing about 2 years later of both AR 2218 and Viht 20N29 with the Hornady 208 grain Amax and Sierra 240 grain HPBT in my 300 RUM indicated that the burning rate of both powders was very similar. My chrono results are listed below:

Hornday 208 grain Amax
99.0 ADI AR2218 2776 Mild Pressure
100.0 " 2845 "
101.0 " 2881
102.0 " 2905
103.0 " 2963 Near Maximum Pressure

99.0 Viht 20N29 2661
100.0 " 2763
101.0 " 2882
102.0 " 2890 Near Maximum Pressure
103.0 " 2901 Max Pressure
104.0 " 2930 Above Max (slight ejector mark)

Sierra 240 grain HPBT
98.0 ADI AR2218 2818 Near Maximum Pressure
99.0 " 2857 Maximum Pressure

98.0 Viht 20N29 2781
99.0 " 2835
100.0 " 2888 Maximum Pressure

Your comments about Rl 50 in your 300 RUM interested me, as I contacted the Australian distributor about 6 months ago, when I heard that it had been released in the US, as I am keen to try it. However, at that stage the distributor had not even heard of it, let alone import it.

The data on the Alliant website on Rl 50 with the 650, 750 and 800 grain bullets seemed to indicate that the powder has a slower burning rate than AR 2218 (H50BMG) with the same bullets. Have you found that to be the case? I certainly would be interested in any data you have on it in your 300 RUM (and 7 RUM)

Regards, Brian

 

[Lefty7mmstw]

Well, I haven't used much 50 browning powder that isn't mil-surp, so I don't know if 50 bmg is faster than rl50. I do know that 98.0 rl50 with the 225 hornady hpbt in the 300 rum is right at 2870 fps with mild pressure. 102.0 grain rl50 with the 225 hornady hpbt will net 3000 fps with normal pressure, but the powder compression is a bit heavy. I suspect a drop tube or a bit of vibration would help, but my brother loaded the 102 grain loads after I stopped at 98 so I din't have a chance to see for myself. Both charges were sub moa in a 9# sporter off sandbags with no brake.

 

[brianwinzor]

Based on your experience of RL 50 in the 300 RUM with the 225 gn Hornady it appears to be a little slower burning than the AR 2218 that I am using. However, until you fire both in the same rifle with same bullet you can never be sure.

I will contact the Australian dealer and see if he will procure some RL 50 (and RL 33) to be included in his next batch of powder that he imports to Oz.

I understand the problems you had in trying to get over 100+ grains of extruded powder in the 300 RUM case. I used a 6 inch drop tube and seated the projectiles .020 short of the lands giving an overall length of 3.800 inches, which required single shot loading. If I was to load to .3660 which is the maximum if I run through the REM 700 magazine, I would be restricted to about 98 grains with the long 240 grain bullet.

My 300 RUM is a standard REM 700 SPS, and when topped with Leupold mounts and Bushnell 6500 2.5 -16 x42 comes out at 8lbs 8 ounces.