Home Forums Reloading Big Game Rifles Is my Load to hot???

I am using a 140 grain Sierra game king in a 7 mm Remington Magnum CCI 250 magnum primer and federal Brass My only concern is I am thinking about using 67 grains of IMR 4831 that is one grain over max give or take than what most manuals say But what I was thinking is I have not set my bullet as deep as I once was. I was setting my bullet to the depth that the Sierra manual said to set it at but I have checked where the bullet touches the lands of the rifling and I have found that I was jumping it Just over a tenth of an inch So now I am wanting to jump it 20 thousandths of an inch so I would have more capacity in the case now so I figured it would equal less pressure so I was thinking about trying one grain more of powder than what the load data says. Is this dangerous? Give me your thoughts? Thanks

Putting the bullet closer to the lands will raise pressure.

^^^^This

OK I thought this was true mostly with harder bullets like solid copper bullets or sirocco/A-frame?

True with all bullets.

OK I’ll agree with you But I thought the more case capacity the less the pressure and the less the case capacity with the same powder charge & bullet weight caused more pressure

Internal ballistics is a fair bit more complicated than that.

Yes Your right but I’m just wondering if it’s going to explode on me?

With one grain over present day "MAX"....

Check and older manual and I'm sure it is higher than they are publishing nowadays....

and there is no real records of massive deaths....

Trust common sense, unless ya don't have it, over what some lawyer approved manual is telling you to do...
They are a reference, not a Bible...

What does your chronograph say? If you don't have one, stick to what the manuals say. And why do you want one more grain of powder anyway? If you don't have enough velocity, buy a RUM.

One good reason to use a chronograph.

The SAAMI pressure spec for the 7mmRM isn't near the top of "safe" pressures in modern bolt guns. As others have said, seating the bullet closer to the lands will boost pressures more. You could even back off further, and reduce pressure a bit more. Eventually, the pressure curve goes the other way as you decrease case capacity.

You are likely nowhere near dangerous territory, but I have to ask: what do you hope to gain by running even more powder? Sierra 140 Game Kings aren't very stout bullets, and thus don't benefit from more velocity. You'd be better off to slow them down than to speed them up. Or, if what you've got so far shoots well, don't mess with it.

As stated above, getting closer to the lands increases pressure.

You also didn't move the bullet out of the case enough to change capacity in any meaningful way.

If the loads you had before shot well I would leave well enough alone.

Also, If you want to tinker with your loads, a chronograph is your best friend

Loads from the manuals have changed over the years and I wonder if the early manuals were pressure tested, if they were, they were tested by copper crushing method.

My Sierra #1 manual suggests 67.5 gr 4831 is max (H4831, I'm sure.)

My Hornady #7 manual says 65 grans of H4831 is max

Ken Waters in January 1981 said 68 grains of H4831 was a "good all-around" load for the 7mm RM with 140 grain Nosler Partition and 65 gr IMR4831 was max

Lyman manual #45 & #46 says 67.5 gr 4831 (H4831) is max

Nosler manual #2 & #7 says 66 grains of IMR 4831 is maximum

Speer manual #11 says 63 gr of 4831 (H4831) for their 145 grain bullet is max

Hodgdon manual #23 says 64 grains of 4831 (H4831) is max behind 140 gr bullet

If I were to find the max in my rifle, I'd run a few rounds past my chronograph. I think I'd stop at 3,100 fps unless there were pressure signs with less powder. I shoot 7mm RM's and in my notes, I either used RE 22 and RE 26 . I didn't find a record in my 7mm RM's of either 4831's, which is odd because I like both powders.

I would forget about playing with "max" loads and strive for the most accurate load.

Anyone who works up loads properly and doesn't just dump powder into the case should never have to worry about that.

As it applies to cases as the variable, it's true.

Historically, on average in hunting rifles chamberings, Winchester brass was thinner then Remington. So in an .06 sized cartridge you could stuff in another grain of powder with equal pressure signs and a bit more velocity. So it's a good rule of thumb as it applies to the case itself, but as previously mentioned, when you introduce additional variable it can get more complicated.

Sierra, Hornady, Nosler, and Spear bullets, all with different bearing surfaces. Weight is only one bullet specific variable.

Yep. For some rifle/brass combos, one grain above max is no big deal, for others it is.

Velocity = pressure.