+ P Ammo Question

Someone more informed can chime in…but I’ve never heard of +P rifle ammo. Only pistol calibers

with a pretty modern gun in good condition you should not have any issues. The "+P" status started in the 70's so I would imagine most, if not all .257 Bob rifles made since then are safe to use with it.

No one is going to be able to tell you for a fact if it will or won’t be an issue for your gun if it doesn’t have +P stamped on the barrel.

That said, +P designates that it’s no more than 10% over SAAMI max and that is a relatively low number on .257 Roberts due to the actions it could have been loaded into. If your rifle was offered in 270 win, that configuration could handle 65,000 psi. You’ll have to draw your own conclusions from there.

Thanks for the responses. I'll try to get an answer from Browning and go from there. I'll let everyone know what I find out.

I shoot the +p Hornady Superformance SSt in my Robert’s . It’s a Ruger M77 built in 1982 according to the serial number. I’ve had no issues .
I bought the ammo so I could keep the brass for reloading but it shoots great in my rifle.

quote:

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+P stamped on the barrel.

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Yes should be stamped on your barrel if not your taking a risk.

They also have +p+ that is even more over powered.

If it's not stamped on the barrel I wouldn't use it and don't see the need for it also.

Me either !!!

Hornady Superformance ????

Hotter rifle ammo by 150 fps or so, in memory serves me

The + P ammo I was going to choose from included :
* Nosler Trophy Grade + P 110 gn Accu Bond
* Doubletap + P 110 gn Nosler Accubond
* Hornady Superformance + P 117 gn SST

I went ahead and ordered 1 box of each of the following to be safe for now:
* HSM Game King 117 gn Sierra Spritzer Boat Tails
* Norma American PH 100 gn SP

We'll see which ammo groups the best.

You do realize you will never notice the difference of only 150fps....right?

So, the tech at Browning couldn't tell me that I can shoot the + P ammo in my .257 Roberts but he didn't say I couldn't. When I asked him what the PSI allowance for an A-Bolt is, His answer was that that was proprietary company information and he couldn't disclose that psi information.
From what I can gather, most modern rifles can handled pressures between 60,000 and 65,000 PSI depending on the cartridge.
For my gun, the + P ammo pressure hits 58,000 psi compared to 54,000 psi for the non + P rounds.
I haven't made a decision on which way I'm going to go but I wanted to share what I found out. I might have to start reloading if I can't get regular factory loads.