+P brass versus 'regular' brass

[Nevada Mike]

I am loading some .257 Roberts ammo (Hybrid 110 and 100 grain Nosler BTs) in WW+P brass. I also have a lot of RP brass not marked +P. When my load is developed I would like to test the same load in the RP (non +P) brass.

What is the actual difference (if any) between +P and regular brass? Is it safe to develop a load in +P brass and then tune it for use in the regular brass?

ALSO - - why is it that no one offers +P loads for the 7X57?

 

[Alistair]

Don't quote me, but I believe that the brass itself is the same, it's just loaded differently and labelled so you can distinguish them.

Thing's you might do to validate this assumption are:

Weigh the brass - is there more material there?
Establish the internal case capacity - is there any difference (weigh, fill with water, weigh again to confirm how much (1cm3 = 1gram), convert accordingly.)
See if the oiginal primers they're loaded with are different - the +P may (or may not) be using a thicker cup primer to better handle the higher pressure.

I don't think the metallurgy would vary, but I'm not sure how you'd easily find out at home either.

As mentioned, my suspicion is that theyll be indistinguishable, but at least this way you'll know.

Please lt us know if you do find anything, I'd be curious to find out!

 

[Joker12]

The headstamp is the only difference. I am using Winchester standard brass for +p loads in my 257Roberts with no problems. I have also used brass stamped +p and found no difference.

 

[Nevada Mike]

Thank you both for your comments... I'll do some checking.

 

[Bob Nelson 35Whelen]

I am loading some .257 Roberts ammo (Hybrid 110 and 100 grain Nosler BTs) in WW+P brass. I also have a lot of RP brass not marked +P. When my load is developed I would like to test the same load in the RP (non +P) brass.

What is the actual difference (if any) between +P and regular brass? Is it safe to develop a load in +P brass and then tune it for use in the regular brass?

ALSO - - why is it that no one offers +P loads for the 7X57?

@Nevada Mike
From what I know there is no difference in the brass. The +P brass just signifies it is loaded to higher velocities and pressures.
Even these so called +P loads for the Roberts are still not at the full potential. The Roberts is SAFE and comfortable with 100 grainers at over 3,200fps and 117grainers at 2,900fps
The old 38 special +P loads also just signified higher velocities and pressures and advised using caution in older or light framed weapons.
Hope this helps
Bob

 

[Scrumbag]

Hi @Nevada Mike I shoot a 257 Roberts with +P data and have done so since 2014. No issues to report. RP brass starting to look a little tired after 6 reloads but nothing out of the ordinary.

Scrummy

 

[Nevada Mike]

@Nevada Mike
From what I know there is no difference in the brass. The +P brass just signifies it is loaded to higher velocities and pressures.
Even these so called +P loads for the Roberts are still not at the full potential. The Roberts is SAFE and comfortable with 100 grainers at over 3,200fps and 117grainers at 2,900fps
The old 38 special +P loads also just signified higher velocities and pressures and advised using caution in older or light framed weapons.
Hope this helps
Bob

Come to think of it, the only +P .257 brass I have seen was LOADED ammo. All the brass bought new has no +P legend

Hi @Nevada Mike I shoot a 257 Roberts with +P data and have done so since 2014. No issues to report. RP brass starting to look a little tired after 6 reloads but nothing out of the ordinary.

Scrummy

I have a bunch of new R-P brass plus half a dozen Hornady and Nosler ammo. Plus some once (or more) fired brass collected over the past few years. Need to shoot some up.

 

[deewayne2003]

I believe the previous comments about .257Rob regular vs +p brass are correct; and I have seen no difference in the actual brass.

Where the difference in brass (regular vs +P) comes into play is handgun ammo. Some +p ammo for handguns is loaded to higher pressure by a couple of different methods.

1. slightly larger powder charge

2. Some +P cases(handgun)have smaller internal dimensions to give +P velocity with standard powder charge