.257Wby range test

[boomer68]

Jerry,

Are you suggesting Retumbo and H1000? The weather up here can definately change quickly, thats for sure!

 

[Jerry 919]

I am totally happy with Retumbo. Start low and watch for pressure signs. You should find what you want around 74, 75, maybe 76'ish. Mine loves 76.5 out of a 26" heavy barrel. I could not get enough H1000 in the case to get the velocity to the 3600 FPS level. I could only get up to 3500 FPS with H1000. I knew the caliber was capable of more.

I get .5 inch groups with H1000 in my 7mm Rem. Mag. and 160 Accubonds and right at 3100 FPS. My son and I both took 6x6 bull elk this last fall with that loading.

Good luck and dress warm. Flopping a coyote at 300-500 yards helps warm you up.

Jerry

 

[FOTIS]

Here is some Retumbo data.

Cartridge : .257 Weath. Mag
Bullet : .257, 110, BER
Cartridge O.A.L. L6: 3.170 inch or 80.52 mm
Barrel Length : 26.0 inch or 660.4 mm
Powder : Hodgdon Retumbo

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 81 58.40 2770 1874 30672 11989 97.1 1.615
-18.0 83 59.86 2842 1973 32866 12299 98.1 1.574
-16.0 85 61.32 2914 2074 35224 12575 98.9 1.533
-14.0 87 62.78 2985 2177 37761 12812 99.5 1.491
-12.0 89 64.24 3056 2282 40489 13010 99.9 1.442
-10.0 91 65.70 3126 2387 43425 13165 100.0 1.395
-08.0 93 67.16 3196 2494 46589 13292 100.0 1.350
-06.0 96 68.62 3264 2602 50001 13415 100.0 1.307
-04.0 98 70.08 3331 2710 53680 13534 100.0 1.266
-02.0 100 71.54 3397 2819 57654 13648 100.0 1.226 ! Near Maximum !
+00.0 102 73.00 3463 2928 61937 13759 100.0 1.187 ! Near Maximum !
+02.0 104 74.46 3527 3039 66513 13865 100.0 1.150 !DANGEROUS LOAD-DO NOT USE!
+04.0 106 75.92 3592 3151 71422 13967 100.0 1.115 !DANGEROUS LOAD-DO NOT USE!
+06.0 108 77.38 3656 3264 76694 14064 100.0 1.081 !DANGEROUS LOAD-DO NOT USE!
+08.0 110 78.84 3719 3378 82362 14156 100.0 1.048 !DANGEROUS LOAD-DO NOT USE!
+10.0 112 80.30 3782 3494 88463 14243 100.0 1.016 !DANGEROUS LOAD-DO NOT USE!

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 102 73.00 3594 3155 76418 13301 100.0 1.091 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 102 73.00 3261 2597 48573 14370 99.7 1.316

 

[Jerry 919]

Pop,

Just wanted to take a moment and thank you and the others for policing this site. It seems to be a full time job lately. Eventually they will grow tired and move on. It must be frustrating.

That aside it is remarkable how much good information is condensed on this sight. Some items have saved me hours, effort, and money.

The table data that you post is not totally clear to me. I do not understand the first column. Most of the rest I get. Can you give a simple "Readers Digest" explanation?

Thanks,

Jerry Lowery
Bend, Oregon
(Non-Socialist side of the state)

 

[FOTIS]

No sweat. This is home to me!

As far as the tables I post basically it is self explanatory is you read above the #'s.

step-- deviation of percentage of specific charge
fill-- percentage of case capacity filled with powder

velocity, energy and pressure max is easy.

propellant burnt---% of burnt powder
muzzle pressure
b_time is burntime in milliseconds

 

[Jerry 919]

Thanks,

What generates this data for you? Does the program consider elevation and or temperature?

Jerry

 

[FOTIS]

yes you can change a whole bunch of variables. Again it is to be used as a reference. It is bot a panacea.

 

[boomer68]

Great info guys. Will have to try some Retumbo as well. Looks promising.

Seems some of my problems could have been related to seating depth. Is Retumbo along the same burning rate as the discontinued H870? That was my favourite powder in my 7mm RM years ago. Used a 162gr Hornady BTSP, and would cluster 3 shots into .75" all day at 100yds. Rifle was a Browning A-Bolt Stalker.

Ian

 

[Jerry 919]

According to my chart H870 was slightly slower than Retumbo. I had a pound of it and loaded a few rounds and it shot pretty well. Did not want to proceed with and obsolete powder so tried AA8700. Not bad but did not deliver the data that I desired.

Jerry

 

[RRIES]

I am glad to see another post on one of my fav cartridges. I am stating what is already being said but the 3 257 Wbys I own can group from 2.5 inches to wonderful little clover leaf pattern and all I do is change the seating depth
I am curious I use IMR 4831 not the slowest burning by far but it has worked well for me. Where can I find info on what powders are more temp sensitive than others? Thanks for the help.

 

[boomer68]

Just loaded up some more RL25 and 7828ssc, this time with a OAL of 3.17" and starting at 69.5grs working up to 70.5grs. Will post my results.

 

[boomer68]

Sorry to open an old thread, but got out to the range and things are looking a bit better. The squares are 1" in size. I got the load data from Barnes for the X bullet. It is 1gr below max.

 

[JD338]

Nice shooting.
Do you know what your MV is?

JD338

 

[boomer68]

Unfortunately no. I keep forgetting to take my Chrony
The group circled in black is from a different load. I also had some 100gr BT and used RL25 and 7828ssc. I am quite pleased with RL22 and next time I am going to load up some 110gr AB, 100gr BT and the TSX with this powder and see what happens.
I also have some 115gr BT and 115gr Part on their way, so will see how they perform.

I am quite pleased with the rifle so far :grin:

 

[TBASTIAN]

Headed out to the range today to do a second test on a pet load for my .257 WBY - 115 Nosler Partitions, 64.0 grains IMR 4831, 100 yards, 58 degrees, 3 shot group. I will definitely be using this as my deer load for this coming fall!

 

[JD338]

Nice shootinig. Looks like you have the load for 115 gr PT's.
Have you tried the 110 gr AB?

JD338

 

[TBASTIAN]

I have. The 110 AccuBond is shooting right at an inch, but none of the bullets touch. I'm also pushing them with 72.5 grains of IMR 7828 which is more than the maximum loading recommended by the folks in Bend.

I was also able to visit the factory a couple of weeks back and discussed both the 110 AccuBond and 115 Partition. I am planning to use this load on Western Oregon Blacktails and Idaho Whitetails, between 100-500 yards. With these yardages the folks at Shooter's Pro-Shop suggested the Partition over the AccuBond at WBY velocities and close range. They said that it would penetrate farther at the close range and keep more of its integrity.
-TB

 

[JD338]

I was also able to visit the factory a couple of weeks back and discussed both the 110 AccuBond and 115 Partition. I am planning to use this load on Western Oregon Blacktails and Idaho Whitetails, between 100-500 yards. With these yardages the folks at Shooter's Pro-Shop suggested the Partition over the AccuBond at WBY velocities and close range. They said that it would penetrate farther at the close range and keep more of its integrity.
-TB

The AB is designed to expand from impact velocities of 3100fps down to 1800 fps. You would be better off with the PT for close shots.

JD338

 

[lazyered]

You're reloader 25 loads seem way to whimpy to me. With a 110 AccuBond I'd say start at 73 gr and work up to 74 or maybe more if your gun is anything like mine. A very accurate load in my gun is 70 gr 7828ssc with a 115 Btip aol 3.250. My brother just got a knew vanguard with a wood stock and we havn't tried that bullet in it yet but it shoots under half an inch with 117 gr sst bullets with 70 gr 7828ssc and I'm pretty sure Btips would do every bit as good. Velocity with the 24 inch barrel was just under 3300. I don't see how the test target doesn't have a better group (just over an inch) when randem reloads beat that without hardly trying.

 

[boomer68]

You're reloader 25 loads seem way to whimpy to me. With a 110 AccuBond I'd say start at 73 gr and work up to 74 or maybe more if your gun is anything like mine. A very accurate load in my gun is 70 gr 7828ssc with a 115 Btip aol 3.250. My brother just got a knew vanguard with a wood stock and we havn't tried that bullet in it yet but it shoots under half an inch with 117 gr sst bullets with 70 gr 7828ssc and I'm pretty sure Btips would do every bit as good. Velocity with the 24 inch barrel was just under 3300. I don't see how the test target doesn't have a better group (just over an inch) when randem reloads beat that without hardly trying.

Sorry, but was that directed at me? :grin: