Home Forums Reloading Big Game Rifles Your most accurate .257 Roberts load with 100 gr. Partitions?

No intention here to hijack the thread but, I read sometime back about using 6 mm Remington brass to form Roberts cases. And more recently there has been mention of that resulting in thicker case necks that may need turning.

I just recently obtained a few 100 gr. Partitions from a forum member and am looking forward to trying them again in my Ruger Hawkeye. The first attempt several years ago, and rounds down the tube, did not produce acceptable accuracy. I have a couple hundred cases that need annealing but I haven't tried that yet.

What's the story on the 6mm Rem. brass?

Hornady 117gr BTSP. For clarity, the velocity is 2765 fps avg.


Never shot any 100 NP from Bob, but they seem to work in the .250 Savage. Bottom target below...

I believe Hornady, among others, is selling 6mm brass.

beefan,

When you neck up brass, the necks get thinner, not thicker.

But they may have been referring to the "dreaded donut," the thicker ring of brass that often occurs at the base of the neck when necking up. This appears because the shoulder area is typically thicker than the neck.

The donut can be eliminated in a couple of ways. One is to run an inside reamer into the neck of fired cases. The other is to neck-up the smaller caliber case (in this instance the 6mm Remington) by pushing the neck over a .25 expander ball, but NOT running the 6mm case all the way into the .257 die. This pushes the thicker donut "out" around the base of the neck where it can be eliminated by outside-turning the neck into the top of the shoulder.

Prezackly.

Just physics, nothing personal...

DF

I don't shoot the 257 bob but I do shoot the 25-06 and found out that it loves RL-22. Not sure why but groups shrunk big time using it.

Seems to me part of reloading is physics, the rest is snake oil...

You just shoot and observe. Figuring it out is often futile.

BTW, MRP is reportedly the same as RL-22 or nearly so. I've heard it's made to highter standards, has less lot to lot variation. I shoot both, just not enough to tell a difference.

25-06 is a good one.

DF

I got some 110gn ELD X bullets averaging above 3,100fps with 47gn H4350. There was no pressure signs, but it was the first firing of new brass. I'm getting a bit over 2,800fps with Hornady 117gn SST's and 48gn H4831sc, also no signs of pressure. The 10 twist seems to favour the heavier bullets, and with a 200 yard zero I'm just under 2" high at 100. Working up the loads to get to 48gn I was getting 3 shot groups around an inch for the most part. The groups opened up to 2.5inches at 200, but that's still minute of deer.

Try primer changes, seating depth changes. Don't dismiss a magnum primer as an option.

I haven't run 100gn Partitions on any of my Roberts' for a long time but used 48gn of H4831sc when I did. These days I load around 46/47gn H4350 with various 100gn bullets so would probably try that powder first.

Loaded 100gr Barnes TTSX yesterday using RL16. First time load in 257 Roberts. But works real well in 270 Win.

H-4350 is my second favorite Roberts powder, behind H100V.

DF

DF: other than temp sensitivity, can you tell any difference between IMR4350 and H4350?

Not much. I see occasional reports of slight better accuracy with IMR, but not IME.

I just like the Hodgdon version. Works for me.

DF

thanks

I've pretty much given up on loading 100 to 110gn bullets for my Roberts. I definitely prefers the heavier 117gn bullets and so far 48.9gn H4831sc is the business. I can't see any point shooting the lighter bullets, I have a 243 for that.

I tried a load JB recommended of 100 gr.partition and 46 gr of H4350 and it shot into 3/4 inch out of my mauser.

Just started loading RL16 in the new Roberts. with 100gr. Barnes TTS"X. They shoot great next step is the chrono. Per this thread will also bump the load up a bit. Using the manual load. Kimber 84M Less than 1/2" groups. I also want to see if I can Partitions 100gr. shooting well.