Very tight cases

[Mobuck]

"I should add that the reason I don't want the +P brass is that it holds about 10% less powder due to the heavier case"

That is not possible.

[pete2]

When I get a new rifle I order 100 or maybe 200 new cases to start with. Don't cost that much, you can even buy the same brand. Pretty simple and it eliminates potential problems.

[NHSHOOTER]

I have a Browning xbolt and when new no matter what shell I put in it it closed hard, after about 100 or so rounds is now closes as it should, I have had this discussion with other browning owners and they too had the same issue..I dont know how many rounds you have put thru yours...

[ShootistPRS]

The brass was cleaned, full length sized with the press camming over and the shell holder and die base in full and pressure contact. If I had turned the die in just 1/4 turn more it would not allow the press to cam over. The cases were trimmed to length, flash holes deburred, primer pockets cleaned and the mouth was chamfered inside and deburred outside. The cases were segregated by make. I eventually discovered that the +P brass had a 10% (approx) reduced volume so they are separated and not used. The Speer #13 shows loads for +P brass with maximum loads BELOW the starting loads for other brass.
After full preparations there are cases that will not chamber in my gun. The gun is a Browning A-bolt that is just over a year old and has been fired very little. The cartridge length from base to datum is .0035" under the SAAMI spec. The gun will chamber other cartridges with longer lengths. The problem I have is that the diameter of the case near the shoulder/body junction and the diameter at the pressure ring of the case (just forward of the solid brass base) are too large in diameter.
I only have this problem with a few of my cases and the rest load fine. The fatter cases will not allow the bolt to close.

The trimmed cartridge length is fine.
The base to datum length is fine. (shorter than the cartridges that do feed)
The die is set to cause as much interference between the ram and die as is possible while still taking advantage of the over-cam effect of my Rock Chucker press.
I have not found any small base dies available in this caliber.

At retail the 5 cartridges are worth about $7. I could throw them away and not worry about it and I may end up doing that but I have a problem that I would like to solve.

For those of you who believe there is no difference between the standard and +P brass - do yourself a favor and actually measure the capacity of the two cases. Using a +P load at maximum in a standard brass could cause secondary detonation and using a starting load for a standard case will cause an over pressure load in a +P case.

Thanks for the chat and all the questions. F.Guffey You have once again shown your innate ability to turn things into a test of superiority and have once again lost. You can't even answer an honest inquiry into the process you used to turn 3006 cases into 257 Roberts cases. I hope you see more when you look into the mirror than I perceive from your posts and comments.

[JeepHammer]

Brass or sizing die?
Stick a shim between brass & shell holder pushing brass up a little and see if this solves your issue.
Automotive feeler gauges allow you to measure how much you shim up the brass.

If this solves the issue, the shell holder isn't getting along with your die.

If the shim solves the problem, take a little off the top of the shell holder so the brass can get a little further up into the die.
The usual crap advise is to screw the die even further down, but shell holder hitting die is a hard stop, and further 'Over Camming' the press does nothing but deflect/bend the ram even more, and stresses the crap out of the press frame.

The usual instructions say to hit die on shell holder, then turn the die in 1/8 or 1/4 turn.
This is to take the slop out of linkages.
Knuckleheads think if 1/4 turn is good, another 1/4 turn must be great...
Often times it's simply the shell holder isn't getting along with the die and your particular brass.

Even though this has been pointed out over & over, thinking through the process often escapes some folks entirely...

[Unclenick]

ShootistPRS,

My first step in your shoes is to look at the SAAMI drawings and measure the case diameters as well as the head-to-shoulder to see what is off. It could prove useful to obtain a box of commercial ammunition, fire a few of them to get before and after measurements and to compare the fired ones to what is coming out of your sizing die.

It is sounding like you may need a small base die for the first resizing of the fat cases, but I don't recall seeing one in .257 Roberts. Still, they make them for a lot more chamberings than they used to, so you might find some, and, obviously, one could be special ordered. However, before going to that investment, it is also important to note that tolerances on a lot of sizing dies aren't very tight. RCBS once sent me information on their small base dies, and I was much surprised to find 0.002" diameter tolerances. I assume that goes for their standard size sizing dies as well, which means something as simple as trying a different sizing die may fix things. Maybe you can borrow one.

Another thing you can try is to run a case into the sizing die, leave it in there for a count of five at the top of the stroke to let the spring relax a little, withdraw it and rotate it about 1/3 turn and repeating the resizing and pausing twice. I've taken -0.003" off the length of a .30-06 case doing that. I never measured what it did to the diameter, though.

The other thing is Mr. Guffey's trick of using an automotive feeler gauge slid between the case head and the bottom of its slot in the shell holder. Usually, there is room to raise it up to about 0.005" that way, so sizing will go that much further. Any way you make your cases go deeper into the sizing die, whether by feeler gauge or by reducing the shell holder deck or by grinding the die mouth back, the shoulders will come out set back more than you want. But after you fire them from that size once, you should be OK sizing them normally with the die set to produce your preferred shoulder setback specification thereafter. The trick is to get them loose-fitting once, then fire them. Tight cases don't normally cease being tight after firing, unfortunately, or you could just jam and shoot.

Though unusual, there are a few instances in which +P cases are made with thicker brass than standard cases are. Starline's .45 Auto +P, for example. I didn't realize the .257 Roberts was another, but then I learn something new every day.

The cases that wouldn't fit your shell holder may have experienced excess pressure. Did you look to see if the primer pockets were loose?

The head of the .257 Roberts is the same as the .30-06 and other stepchildren of the .30-03, so you should be able to form brass from .30-06. RCBS forming die set #58118 makes 6.5mm-257 Roberts from either .257 Roberts or .30-06. You could first form 6.5 mm-257 Robers from .30-06 with that, then neck it down with bushings. You'll need to inside-ream or outside turn the necks to remove the extra neck brass thickness that will result.

Originally Posted by Nathan

Redding makes shellholders meant to push the case in further...

It's the other way around. Their competition shell holders have taller decks in 0.002" increments to keep the case from going in as far as normal and pushing the shoulder back too far. This is to allow you to just set the shoulder back slightly but still make solid contact between the die and shell holder for consistency.

[30Cal]

I would just call Redding. You may need to get a tighter die.

Just measured the only unmolested 257 Roberts brass I can find. This is one measurement each of a single case of both flavors:
New Rem 257 brass - 53.0grs water
Once fired Hornady 257+P - 53.5grs of water

I shoot Hornady 257+P and 6mm Rem brass in a 257 AI chamber. I get identical velocities out of either. For whatever that's worth...

Weird that your experience is much different.

[JeepHammer]

Same old wives tale...
Don't think the process through, just tell the guy to screw die in further!

When the shell holder impacts die/press frame, and the slop is taken out of the linkage (the reason for 1/8-1/4 turn past contact in the directions) you are excessively loading press frame, ram & linkages.
It's hard metal on metal contact, in the machine world calls it a 'Hard Stop'.

Since the shell holder is solidly against the die, the brass has stopped moving, it's just along for the ride in an airspace pocket in the die.

Now, simply shim the case up in the shell holder.
Shim between case head & shell holder floor. Nothing more to it.
This pushes the case up a little further in the die and it's slightly resized a little more.

I recommend automotive feeler gauges since they are marked for thickness and will tell you how much needs to be taken off the top of the shell holder for a properly sized brass.
Once you know how much to take off, it's simple to measure the thickness of the shell holder with a caliper.
Flip the shell holder over on a sheet of Emery cloth, keep it flat, and take off what's needed.
Use your calipers to keep track of how much is coming off...

Shell holder are the CHEAPEST parts to modify in the event you use the same die with other rifles, a 'Factory' shell holder purchase puts you right back to making brass for that rifle, assuming the factory parts worked for that rifle...

Now you have a shell holder that matches YOUR dies, and produces brass for YOUR rifle.
Keep the shell holder with the dies for that particular rifle.

After Hounddawg posted about color coding, my dies & shell holders are getting coats of paint.
Kills rust & makes for easy identification.