257 Roberts brass question

[waco]

I just got a new to me 1983 Ruger M77 Bob. I had a member here make me some brass. He used FC 30-06 to form said brass. My Hornady manual says there is +P brass and STD brass and that all their loads are based on +P brass. How strong is my formed 30-06 brass? how much should I reduce loads if any?

For now I'm going to load Hornady 100gr Interlock bullets. I'll probably use R15, IMR4831, and Varget to start with.

Not sure if I'll run cast through this rifle or not. I know the brass wouldn't be an issue then.

It might be my new rock chuck/yote gun.

Thanks in advance for the help.

Waco

[GRUMPA]

Read this, it may help clear things up for you.

https://www.shootersforum.com/handloading-procedures-practices/49657-257-roberts-p-brass.html

[waco]

Read this, it may help clear things up for you.

https://www.shootersforum.com/handloading-procedures-practices/49657-257-roberts-p-brass.html


Awesome! Thanks again Matt. That's just what I needed.

[CLAYPOOL]

IMP 4350 is supposed to be the powder. I used IMR 4064 35.5 grains = Book load. for Serria (sp) 120 grain bullet. 36.0 grs. with Serria 120 Boat tail. I do mol;y coat . Lots of people don't like it, But I do....

[HangFireW8]

Fill formed versus factory with a suitable powder and weigh to help determine case volume differences.

Watch neck thicknesses and neck length to avoid pinching the bullet in place and raising pressures.

[waco]

I don't have any factory brass.

All the formed brass has had the necks reamed.

[runfiverun]

if you look closely many of the 2 types of loads out there are duplicates.
the plus-p loads are in plus-p marked brass, and the non plus-p are in normal cases, this tells me the plus-p brass is made with a thicker base.
this might seem odd but I use the plus-p brass to make 7x57 rounds from and normal cases to make the Bob rounds from.
27-2800 fps is a doable goal with most bullets and is where most of them do their best work anyway.
I like the hornady 120gr hollow-point and the 100gr interlock, both work at that velocity.
you can also just run 6mm rem brass through your size die and be fine, it is made to take whatever sane pressures the gun can handle.

[skeettx]

OK, it has been 10 whole days, how does the gun shoot??

[atr]

I find IMR 4350 the preferred powder for my Remington model 722....
my barrel twist may be different than yours, but I get really fine accuracy with 87 gr-J at 3200 fps
and also with 117gr RN at the 2700fps range

[HangFireW8]

I don't have any factory brass.

All the formed brass has had the necks reamed.

In that case, check for neck thickness uniformity with a tube micrometer.

[sniper]

The 257 Roberts and 6mm Remington are said to be derived from the same mother brass...7 X 57 Mauser. That being true, 6mm expanded to .257 or 7 X 57 necked down might be a solution.

[Littlewolf]

are you the one that reamed the necks, if so did you use the rcbs neck ream die and reamer?


I don't have any factory brass.

All the formed brass has had the necks reamed.

[GRUMPA]

are you the one that reamed the necks, if so did you use the rcbs neck ream die and reamer?

I'm the guy that made those for him....

[EDG]

>>>the plus-p loads are in plus-p marked brass, and the non plus-p are in normal cases, this tells me the plus-p brass is made with a thicker base.<<<

You cannot make that assumption. I think all you get are Plus P loads and the brass is so marked but it is the same old brass.
The hardness of the brass is more important than the head thickness.

The highest pressure loads in the .30-06 case head size are .270, .25-06 and 6mm Remington.

If you buy lots of these cases once fired you will find about 2% blown primers if you decap by hand with the 6mm Rem being the worst followed by the 25-06.
I get them from an indoor range so I know they are once fired.