Why no rifle rounds in +P

C

ckpj99

New member
So, I have a sort of dumb question. There seems to be +P versions of pretty much every type of handgun round. Though, I've noticed that there's no such variation in rifle rounds.

I'm pretty new to rifles. I've only really gotten into them in the last couple years, and I've only been reloading about a year.

So what's the deal with rifle round pressures. I have a hard time believe that no one has even said, "man, this round would be better with a hotter powder."

My only theory is that this has happened, but the new loading is just called something new.

That being said, it seems like there's such a wide variety of rifle rounds that pressure would be more of a concern.

I'll be purchasing a .30-30 soon, and I've seen all sorts of rounds. Buffalo Bore has a 190 grain load that travels as fast as some 150 grain bullets. It has to be generating a lot more pressure. If normal guns can handle that much pressure, why aren't there 150 grain loadings that go much faster?

I'm just a bit confused. Can someone explain to me why I don't see +P rounds? Why is there such different in commercial loadings for a lot of rifles (especially hunting rounds)?
 
I'm wondering too, the 45/70 comes to mind, 280 Rem vs. 7 mm Remington Express, 244 Rem vs. 6 mm Remington, and the 223 Rem vs. 5.56 mm NATO.

Of course then, what would we have to complain about, while on the internet?
 
The only one that comes to my mind is the .257 Roberts +P. When it was first introduced, it was loaded to a tad bit lighter pressure & velocity. My only guess is they wanted to keep the diffrence apparent for folks with older semi autos or otherwise possible weaker actions that were designed for lower pressured ammo.

I'm guessing they could have made the 6.8 Rem SPC into a +P when it was boosted up to the SPC II specs. Why not? I dunno, as far as I know- the only way to tell which pressured round you have is by looking at the box.

That's a good question though. And by that line of thinking, just about any .30-06 that isn't Garand approved ought to be .30-06 SPRG +P, huh?
 
As noted there are some +P loads out there, mainly for older rounds that have found their way into newer, stronger actions.

You get more out of a pistol round by going from 25 to 27k PSI than you do from a rifle going from 55 to 57k PSI.

So that is why you generally see +P loads for older, lower pressure rounds and pistol cartridges.

Jimro
 
Leaving out the souped up versions of older cartridges in modern rifles, our common rifle cartridges are already loaded to an industry standard of known, safe pressures. And, generally, there is no perceived need.

The Federal Premium High Energy and other equivalents might be considered as +P in velocity, but are said by the manufacturer to not be loaded to higher pressures. I assume the same is true for Hornady.
 
+P denotes increased pressure, not necessarily more bullet speed. Even with handgun rounds +P does not always mean more performance. There are lots of non +P loads that are often faster than some +P loads.

There are lots of rifle factory and handloads available that will improve bullet speed without exceeding normal pressure limits. Some companies market them under various names. The discontinued Hornady "Light "Magnum" loads and their current "Superformance" loads are 2 that come to mind. They improve bullet speed by 100-200 fps, but since they do it without exceeding max chamber pressures, they are not called +p.

Handloaders often work "off the books" and work up loads that exceed listed pressures. This probably should be considered +P.
 
In the 1890s or early 1900s ammo companies brought out a series of cartridges, including .32-20, .38-40, .44-40, and .45-70 (possibly others) that were designed specifically to give higher velocities in the Browning-designed Model 1886 and Model 1892 rifles.

I suppose those could be considered to be the first +P rifle rounds...
 
It depends on how you define +p if you go by SAAMI standards then there are really only a few handguns with a +p designation. If you go by what manufactures like Buffalobore market then there are plenty of +p rifle and handgun rounds but cavet emptor as they don't adhere to SAAMI standards.
 
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There are +P rifle rounds. The reason there aren't more is probably because most rifle rounds run upwards of 60,000PSI already, and increasing that pressure further causes more barrel wear, without much gain in performance.
Saami max for the 30-06 family (.270 win 280 rem, etc) are all around 65K psi, which is about the same for most 'magnum' cartridges. The .308 family has a max pressure of around 62K PSI, so again not much room for +P without getting into 'proof load' territory. There's not much gain in pushing those cartridges past their limits. Now in the case of .257 Roberts or 7x57 the max SAAMI is only around 51K PSI, so there is more to be gained.
 
Can someone explain to me why I don't see +P rounds?
Click to expand...

I don't know if I can, but I'll give it a shot! or at least some points to think about..

First off, compared to rifle rounds, pistol rounds are low power and low pressure (exceptions are some of the "hand cannon" rounds above .44 Mag)

SAAMI specs are agreed upon, not mandated. A +p rating usually indicates about a 10% increase in pressure. A 10% increase in an 18K psi round is a different matter than a 10% increase in a 55K psi round.

Another thing is that pistol rounds are much more limited in their possible size than rifle rounds. Want more from a pistol, you have to increase the pressure. Want more from a rifle, you can use a bigger case, burn more powder, and keep the same pressure, essentially.

In other words, if you want more than a .30-30 gives you, you don't jack up the .30-30 pressure, you go to a .300 Savage, .308 Win, .30-06, etc.,

I'd say the ease of just going to a larger rifle round is the main reason you don't see +p rifle rounds, no demand from the market.
 
So I guess the general consensus is:
1) there are a couple "+P" rifle rounds that are designated for new actions built to handle the increased pressure.
2) Hotter versions of rifle rounds are invented and developed, but they are usually renamed and possibly changed a bit in dimension. A pumped up .30-30 becomes .308 Marlin, and stuff like that.
3) Rifle loads are pretty much near max pressure for normal rifle construction, so increasing the pressure a bit would increase barrel wear without producing much more velocity.

These all sound like very reasonable explanations. Thanks for explaining all of it. There's a great wealth of knowledge here!
 
In addition to the reasons mentioned above I recall a number of top notch shooters and reloaders-Elmer Keith, e.g. have found that maximum loads are often not that accurate. My modest amount of experience with +P handgun loads led me to conclude they do nothing for me, as we have discussed many times regarding use of minor calibers or "mouse guns" for self defense, hits with minor calibers hurt worse than misses with majors. I am not much of a rifleman or a hunter (nor do I play one on the Internet) but it seems the same consideration applies whether at the range or in the field.
 
I think the main reason for modern high-pressure cartridges would be runaway combustion. You'll increase the maximum pressure rapidly without gaining any more performance; you want to keep the pressure at a given max for longer in a rifle to get more speed. Unlike a hand gun that has a limited barrel to accelerate the bullet.
 
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