Just purchased a 257 Roberts and looking for a starting load work up, any one have any ideas???

I am currently developing a load for my .257 Roberts using 100 grain Noslers and IMR 4064. So far accuracy is promising. While I am on the topic, please give the grand old cartridge and its developer the late Maj. Ned Roberts the respect it has earned. It is the .257 Roberts, NOT "the Bob".

The two best powders I have used in the 257 R is IMR 4831 and IMR 4350

If it's a rifle suitable for modern pressure, then one source outside of standard 257 data is 6mm Rem. data for the same weight/style of bullet.

H100V gave me best velocity and top accuracy.

Not the best for temp stability but one to try, working up a .257R load.

DF

Link:

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/10398672

Great info Dirtfarmer... Thanks

Glad you liked it.

I get a lot more than I give here on the Fire.

DF

You give a lot here.

Hodgdons H100V meters well (use a custom set of Lee type dippers) and I use a fair amount of it in various cartridges. Chuckle, have even done respectfully with it in .308 Win and you will not find any published load data for it....fellow range member ran Sierra's quick load for me as an experiment.

Its one of my favorite powders for the 7x57, the 257 Roberts big brother. Does well for me in my 257R rifles too.

RL22, Norma MRP, RL17 and Hornady Superformance all gave
much higher Velocities and equal or better Accuracy. I
mostly use Nosler 115gr Partitions and 110 Nosler Accubonds.

H4895; 41 grains with 100 grain BTs and Partitions or 38 grains with 110 grain ABs.

For light bullets 100grs or less IMR4064 works real good.
Most people usually start with IMR4350 or H4350, for
heavier Bullets. RL22 and Norma MRP gave substantially
more speed with 110gr and heavier bullets.

RL 19. I've used either the 117 hornady spbt, or the 115 ballistic tip with RL 19 for years and have no reason to switch.

H100V was inconsistent for me. Had some great groups, and then upon testing the same load couldn't duplicate the groups. Oh well.

I found a Ken Waters Pet Load that works well for me. 43.0 gr H4831SC over a CCI250 Magnum Primer and a Sierra 117 gr Game King BT or a Speer 120 gr Spitzer SP. I get approx 2750 to 2800 fps from a 24 inch ER Shaw barreled Rem 700 SA Both loaded to OAL 2.8 in. I have shot 5 round groups under an inch when I'm doing my part, which is getting harder to do these days.

I just got 200 blem 115 gr. NBT's from SPS, arrived today. I already loaded a batch with 44 gr. H-4350, which in my Brux/ LA 700, shoots sub inch. One three shot group was .36", with .04 jump and 2.9" COAL. Don't try that in a SA gun with 2.8" box mag.

This load is a real killer.

DF

Every load book ever made has Bob loads, nothing magical about the cartridge. The load below came from a book dedicated to those with double vision. Don't recall the bullet specifically, but it's one of those 87 grain pieces of odd.