Loading manuals are designed to be a safe load in most all modern firearms. None of the data is intended nor should it be considered as an absolute. This is why it is always desirable to work up loads rather than starting with the max published load.



Every chamber and every bore is slightly different. Accordingly, chamber pressures deviate from rifle to rifle. Therefore, what is considered well above max pressure in one chamber can be safe in another. I have only seen a few guns which achieved max safe pressure before the max load as listed in loading manuals. This is because most manuals err on the side of safety - thanks to product liability awards.



When loading, I work up to max published charge weights and monitor velocity and accuracy. Only in a few rifles do I find maximum accuracy at maximum pressure. Since accuracy is far more important to me than velocity, I stop when I find my best group. Generally, this is within 1% to 3% of max charge weight.



I do have two rifles which achieve safe pressure and accuracy at slightly hotter than the max published load. Remember, chamber failure can occur from metal fatigue. Metal fatigue is accumulative - lean on it too many times and bad things can happen quickly.



I do not blindly trust loading manuals. There are an excellent point of reference, however, there are too many uncontrollable variables to consider them absolutes.

I tend to start about 2 grains below what a manual says and work up to pressure signs and back off a grain or two.

What do you all consider max loads? Is it when pressure signs show up and then you back off a grain or two like me, or is it what a book/manual says is max? Also why is it that 270's are shown in most manuals loaded to higher pressures than say a 30-06 or better yet a 280?

If no pressures signs show them selves when I get about 10% over published max am I at "max" yet?

In my experience w/ 270 win, You cant hardly overload the cartridge w/ a 150 grn bullet and a slow burner like 4831 or R22 etc. The capacity is not enough to be dangerous w/ those powders but, that is not to say that it would not be dangerous w/ faster powders because IT IS! W/ the load you mention I get 3015fps w/ 150 grn Hdy ILSPs out of a 22" barrel.

Magnums is usually where the slow burners get dangerous.

Good Luck!

Reloader

The book is a tool, that's all. I load to a attain the vel./accuracy comb I want & stay below pressure signs. If that means running @ the top end, then that's the way it goes. I used to have a .220 swift that shot sub 3/8" groups all day w/ one load but if you exceeded the load by much more than 1/2gr on hot days, blown primers. I load for several wildcats so a book isn't even an option.

"Also why is it that 270's are shown in most manuals loaded to higher pressures than say a 30-06 or better yet a 280?"
My thoughts --
The commercial 270win is considrably younger than the 06 and was standardized to a higher pressure level. I believe the the 280 originally was chambered in the Remington auto and pump and hence the lower pressure level. There is no good reason why a modern bolt action 30-06 or 280 cannot be loaded to the 270 preassure level. BTW I get 2915fps with my 270 and a 150 partition, RL 22 at Noslers published max, in a 24" barrel and my brass last a long time. For hunting - when I get an accurate load near published max I stop. I don't load until the bolt sticks or primer pockets get loose. Not worth the risk. If I wanted 3100+ with 150 .277, I would have 270 WSM or 270 Whby.

Max always seems to work out for me to be something less than max to others. If you study ballistics to any degree you would find that the miniscule trajectory improvements you get from a normal max load are hardly worth the risk of overloading.
I know my .300 WM never made the 3000 fps mark with 180 gr bullets.
I know my .260 Rem makes right at 2650 fps with 140 gr. bullets.
The rest seem to just follow that conservative loading pattern.
I'm all about value, safety and teaching my son the safe way is the right way.

I tend to go over MAX,with straight walled cases like the 45/70Gov and 444Marlin.When I see the primer starting to flaten,that is the load I keep.With the necked cases 222,30-30,and 308,I look for the primer to start to flaten,then I back off some.I put the bullet on the lands,with the 222 and 308.

I dont see why people dont think the 270 win will not go over 3000 w/ a 150grn bullet. There are several factory rounds (fed HEs) that will do 3000 and you know that a factory load is going to be safe, Believe me they do alot more testing than we do. I have several manuals that show a 270 win breaking 3000 w/ a 150grn bullet.

My mod. 700 rem 270win loves Hdy 150s @ 3015fps, I can get .5" groups at 100 w/ them. And I belive that I could get another 50 fps easy but, what is the need. These loads are slightly compressed but, that helps in some cases.

Reloader

There are several loading manuals that show 3000 fps or a wee bit better is possible with a .270 Win & 24" barrel, which I'm guessing is right at 65K psi. Most manuals list 2900-2950 fps tops. I suspect if someone is getting 3000 fps out of a 22" barrel (which I have seen over my chrony w/ no pressure signs), things are probably slightly over, but maybe right at max pressures. I think it's been discussed a ton of times here that just because you see no pressure signs, does not mean you are not well over established limits.

For the .270 & .280, I've always thought 2900 (+/- 50) or so was reasonable max velocity with a 22" barrel & 2950 (+/- 50) is reasonable in a 24" barrel. This is not based on pressure data, just my own reloading experience as to where I've seen pressure signs with both calibers in different rifles in the past & the tons and tons of literature I've read over the years.

Of course, new powders in recent years may be changing old assumptions. Magpro literature shows slightly over 3200 fps with 130 grain bullets in the .270 & 24" barrel, and my own chronographed results confirmed the velocity. Originally bought Magpro for my .270 WSM, but couldn't help trying it in my .270 Win.

Velocity & hot-loading always confuses me. It's not relegated to the light bullet, high velocity guys either. Even some of the medium bore guys will brag about how they can load their Whelen w/ 250s to 2600 fps or their .338s with 250s to 2900 fps when most loading data shows 2400-2500 fps & 2700-2800 fps respectively.

On the other hand, I don't have a problem with hot loading either. Just don't tell me it's not too hot when 99% of other resources say it's too hot.

-Lou

Look if you must go over 2900fps with a 270,you must go to the Weatherby.The Weatherby 270 MAG,will hit 2300fps with 72.2gr of RL-22.Can you cram that much powder,in a 270 Winchester case?

I agree that sure is one hot 270 Win.
That is about the same velocity i get out of 7 mm Rem mag, at very close to max pressure.

And that out of a 22" Barrel is damn near amazing , I would suggest you either back off a bit on the charge , or have your chronograph checked out .

I have almost never seen good accuracy come from very hot loads , and do not push for that last bit of velocity , if you want a faster gun ....... Buy a faster gun..... There is just another excuse to buy one more

Rudie

The most accurate load in nearly every rifle I ever loaded for was right on the edge.

I guess every one of my shooting buddies needs to get new chronies and new data manuals. We ought to just throw out our sub 1" loads, I guess we will just start over from scratch.

Oh! I forgot to mention that I get 3215 fps w/ 130 SSTs.

Come on guys, we can get these velocities any day and the pressure isn't too high. It is definitely on the verge but, why not get the most out of your equipment. I dont mean be dangerous but, the companies that publish hot loads have done far more testing than any of us.

Oh yea, I bet you would really freak out if I said 3400 fps was possible in a 7mm Rem mag. w/ 140 grain bullets.

I would not recomend anyone who is new to reloading to experiment w/ max+ loads but, if you are experienced and love "Wild Cat" loads, go ahead. Some rifles will shoot great w/ hot loads.

Good Luck!

Reloader

Dont 'hot' loads cause considerably more wear to your gun? If they do I guess I would rather shoot a few hundred fps slower and not have to replace the barrel prematurely. If they dont im all for them I guess.

SKB & Stinkers, put me in your corner. I dislike running any machine at the top end as a given thing. And when the excessive demand causes them to fail, they will do so at the most embarassing moment. It is ever so much harder on them than say 90-95% of top. In truth, as posted, other than the "boy howdy, look what I can do" factor, the gains are mostly smoke and mirrors.
That does not mean that I don't agree that many modern, bolt action rifles can be taken "over the book". And still be within the parameters I mentioned above. Doing so however must be done with circumspection and knowledge as each rifle is a rule unto itself and must be treated as such. There is NO "how far over the book can I go and still be safe' information of a generic nature available.
This is one of the places that a chrony can be very useful. Often, as you approach or exceed the book max, you will see your velocity curve flatten out. You are not getting pressure signs but you're not making any gains velocity wise. You're merely burning more powder. So, to continue adding powder until you get pressure signs is pointless and gaining you very little or nothing.

Yes, they are a little harder on your gun but, not enough that the average shooter would even come close to wearing it out. If you shot 100s of rounds a week through your weapon, you might be concerned w/ hot loads but, most shooters dont put a hundred rounds through a rifle in a year especially a hunting rifle. I dont load hot charges just to go shoot all day, I load hot charges to hunt w/ so that I can get the best perfromance from my weapon. If I just go to shoot for good groups, I wouldn't load hot rounds.

Some rifles do not like hot rounds and some do. I can get sub. 1" groups w/ hot loads out of several of my hunting rifles but, on others I shoot pretty tame loads.

Reloader

I know what you mean on the Short Mags. I can barely beat my 30-06 w/ my 300WSM. They are so close I really dont see the need for the larger except, it has been far more accurate for me. I believe that is mainly due to the short fat case (ensures proper powder burns when the primer is ignited).

Reloader