Reverse engineering

[apache12]

Can you pull bullets form factory ammo and try to figure their load?

 

I have a buddy in Tucson and he has a new 257 wby. Saw mine last year and liked the shoot

 

I know all rifles shoot differnt but I sent him some loads that work for me and they were less them impressive. Nothing to even work with

 

Then. He bought the cheapest weatherby factory ammo and they shot decent. At least as starting point

 

Looks like 100 grain spittzer bullet and I thought I'd call weatherby and ask what they use for powder

 

Am chasing ghost?

[lancetkenyon]

Brass, easy.

Bullets, not too hard, since they are usually listed on the box.

Primers, depends a lot of brand.

Powder, charge weight is easy. Powder type is something else.

 

I doubt Weatherby will tell you a recipe. Some others might know however. I think Weatherby uses Norma powder. Maybe MRP-2?

[apache12]

Yea up against it. Our hunt is in a couple weeks. We started the process to late to find a good load for him

[Hoss50]

My 257 shoots really well with berger 115gr VLD over 61.0gr of h1000.

 

It shoots 117gr hornady interlock well over the same charge. I shoot formed 7mm Rem mag brass though so your pressure will be a little lower than mine.

 

If it shoots the cheap 100 gr weatherby ammo decent then shoot that if you are really too close to the hunt.

[apache12]

Yea I think he'll shoot factory

 

I been using rl 25 wih hdy 117 and imr 4831 with Barnes ttsx 100. And they work great for me.

I may try H1000 after the season just to play with some new loads. Maybe accubond 110

[roninflag]

my mark v .257 is still a mystery. tried a lot of different loads. I would try a lot of 7828 and a 100 grain bullet. factory ammo for sure the primers are 215 fed, powder either mrp or re-22.

[L Cazador]

Great post, yeah what shoot's great in one rifle isn't always going to shoot great in another rifle! This is why you should only use a friend's recipe as a reference point. Weatherby uses a proprietary powder which I'm sure they won't reveal. Norma MRP2, H1000, and RL-22 are all great powders for the 257WBY with 100-110g bullets. They worked great for me with Barnes TTSX 100g. Oh by the way use only magnum primers for consistent ignition. Don't get too crazy experimenting with loads or you'll burn the bore out before you find one, lol!

[apache12]

How many rounds on 257 down the pipe before burn the bore on average

[firstcoueswas80]

Mines looking like it needs replaced right at 675.

[Hoss50]

I am sure I have more than that down mine and it n is still going fine. I don't push my loads super fast though. I am probably shooting loads that are more like a hot 25-06 or mild 257 weatherby.

 

I found a super accurate load, and I shoot that load. I don't care how fast they are, they are accurate. I have shot probably about .75 MOA at 500 yards with this load.

[Hoss50]

Some of my loads are very low powered though too because I make my brass from 7mm Rem mag brass or 264 win mag brass. The first loads on every case are mild 2506 roughly to fire form them. Then I push them higher. That accounts for probably 120 rds of the roughly 700-800 I would estimate I have shot.