Maybe I'm looking for something that I can't find with the limitations of the gun/caliber but I'm running out of ideas. How would you develope a load?
Gun: New Mark V Weatherby .257 Weatherby mag - Factory barrel, Swarovski 6-18 x 50 scope, Burris Signature Rings with offset inserts. Harris bipod, scope level, PK Brake.
Criteria: Develope a load that is accurate enough for deer and pronghorns out to 1,000fpe at impact with either of the 2 bullets listed below.
What are the steps (and in what order) do I take to find an accurate LR load for this gun? I really, really want to get either the Wildcat RBBT 130 gr bullets or the Berger 115g VLD's to work in this gun. 1:10 twist. But, I have other bullets sitting on the shelf if the gun won't shoot with either of those.
The limitations are:
One, or at the most 2 brass suppliers (Norma and Weatherby, but I think Norma makes the brass for Weatherby), and it's a factory gun.
Supplies on hand:
Primers: Federal GM215M, GM210, Federal 210, Win WLR
Powder: H-1000, Retumbo, Ramshot Magnum, H-4198, IMR-4198,
H-4831, IMR-4831, H-4831SC, IMR-7828, RL-22, RL-25
Bullets: Berger 115g VLD's, Wildcat 130g RBBT ULD HP,
Sierra 100g, 117g Gameking BT, 100g Matchking,
100g, 117g Pro Hunter, Barnes 100g TSX,
Nosler 110g Accubond, and 115g Ballistic Tips
Brass: 200 New Norma cases
200 New Weatherby cases
Other reloading stuff: Electronic scales, Concentricity gauge, Redding bushing neck sizer, RCBS FL die set, VLD Chamfer tool, Rockchucker Supreme press, Chrony chronograph, and other usual loading stuff.
I can shoot behind the house out to 350 Yds every day after work, and I also can drive an hour one way to a 1,000 range.
Has the barrel been broke in? I would have a good accuracy minded smith inspect the rifle before I messed around with loads. Check bedding/float, bore scope the crown, throat and rifling. I would do this because your pressed for time and a $50 dollar inspection might save a $100 headache. Not to mention wasted components.
Have you checked this site and the net for common accurate loads? If so start there.
Start with the bullet you hope to use. Prime and load with a sutable powder. Shoot at 100 yards to see if the bullets cut a round hole. If they do try them at 200 if your getting nice round holes the stabillity is there. Check the speed and read the pressure. Now work on the accuracy.
Seat to max oal of the mag, load 5 with said powder, increase .5 grains and load 5 more, ect ect, don't exceed book max.. Shoot for groups at 100. If you see somthing that looks good try at 300.
If after 25 rounds it looks dismall switch powder. Repeat.
If that looks dismall try it as a single shot and get close as possible to the lands, If this dosen't work switch bullets and repeat.
Once the brass has one firing, neck size and try again, this could make all the difference. I've had 1.5" loads turn into .5" loads just by using once fired neck sized brass.
On the same token I've had guns that prefered fls brass.
don't think you'll get the 130's to fly in a 10 twist, but you never know, try a close to max load of re22, 115 berger, fed 215. see how it does. you won't get close to the lands with anything anyway, next I'd try the 110 accubonds.
So far, the 130's are poking round holes at 100 and 200 Yds, the only problem is that it's more of a shotgun pattern.:( I've got some loaded with Retumbo and with Ramshot Magnum (both the 130's and the VLD's) to check velocity/pressure tomorrow. After that it's off to RL-22.
If I start out at SAMMI OAL, and want to move the bullet out towards the lands/grooves, what incremental moves should be made? From testing in another .257, I have found that the closer to the rifling, the higher the pressure, so I will have to watch that if they get moved.
CoyBoy, thanks. You are close to where I attended college, UWSP. The gun is new to me, but when I got it it had 57 rounds thru it. It looks like it'll shoot, just have to do some quick dialing-in. I have a .257 Wby Vanguard that will shoot <1/2 moa, but it's with 100g TSX's and it's over a pound heavier than the Mark V. This one is easier to pack, and with the longer barrel I should be getting more velocity vs. the Vanguard. All I need to do is get to shoot.
I was there when they were building the Sentry building, and they dug the lake for the fisheries dept. in return for the fill. I ain't saying the year!;)
We had to keep the guns in the armory, but I did hang a real nice 10 point buck from the tree in front of the dorm.
I measured the distance from the base of the case to the lands. 4.050" I can't get close to the lands without barely keeping the bullet in the case with 125g FB HP Wildcats, let alone anything of a lighter weight.
In my experience, I have only seen one 25 cal rifle that shot any bullet heavier then 100 grains really well. By that I mean close to 1/2 moa. That was a 257 Roberts in a Ruger M77 if you can believe it with the Hornady 117 gr.
I have yet to see any 25-06 or 257 Wby that will consistantly shoot a heavy 25 cal bullet under 1 moa all the time. Now 100 gr bullets, thats a different story, many will shoot a 100 gr bullet very close to 1/2 moa with the right loads if there are no mechanical issues with the rifle.
I have also noticed that the 25 cals tend to be as finicky as any when it comes to bullet designs, at least in factory rifles. I have developed loads for several 25-06 and 257 rifles that would shoot the 100 gr Flat Base bullets great and shoot the 100 gr boattails terribly!!!
As far as accuracy goes. If a bullet shoots well at 100-200 yards but goes to heck at longer ranges, its likely a stability issue. Even if your seeing round bullet holes. If you are seeing nose tears on the paper, you have severe instability. There are many variations of instability. Some so minor that you can only tell by poor groups at long range or dramatically lower BC then there should be with that bullet.
I have given you some tips already for your rifle.
For me, powder choice means very little with accuracy. By that I mean, if you are getting very poor accuracy with one powder, changing the powder will most likely not improve accuracy to the point it will save the day.
If you have a good load but think the rifle will get you a bit better accuracy, then testing other powders to tweak your load may improve groups but thats only when starting with a bullet that your rifle likes. If your rifle does not like a bullet, does not matter what you put behind it, it will not shoot, period.
Again, I would load up increasing powder charge a grain at a time until you topped out in pressure, then back off a grain or two to a safe comfortable top working load and test at long range. I would shoot at 350 yards, if they do not group well at this range the rifle does not like them.
I have also found that with a finicky rifle, generally, a soft bullet will shoot better then a hard bullet..... By soft I mean a conventional cup jacketed, lead core bullet design. By hard bullet I mean an solid or partitioned bullet. A Ballistic tip or accubond is what I would call a semi hard bullet because of their very thick base which will not bump up under pressure.
If I load up a bullet and shoot at longer range and it does not shoot, I pass on that bullet because if your using an appropriate burn rate powder to start with, changing the powder will likely not make alot of difference down range as far as accuracy goes.
Hate to say it, but if the 130 gr bullets are not getting you the accuracy you want, go to a lighter bullet, I would say try the 100 gr bullets. I know you want to be able to shoot to longer ranges but if a rifle will not shoot the long range bullets, it really does not matter what your shooting out of it. A 100 gr bullet will give you 500 yards easily on pronghorns and most likely on mule deer as well.
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