.243 Win. load question

[rdl65]

I have been testing some loads for .243 with 95gr NBT and Varget. My best load was 3gr. over recommended max load. 35gr. is max load in the reloading manual and I am using 38gr.

I know reloading manuals are conservative because of liability issues. There are no signs of too much pressure that I can tell. The primers on factory loads are more flattened out than the ones with this heavy load. I haven't run this load over the chronograph yet but will next trip to the range.

Am I using a load that may eventually cause trouble? What do some of You reloading experts think about this?

 

[DRAM40A1]

Re: .243 Win. load question

I'm 2.5 grn over max for 105 amax according to Hornady. It all depends on your barrel, your brass, and your chamber. As long as you are comfortable......rock on. I'm pushing 105 amax to 3015 in RP brass with H4350.

 

[EagleI79]

Re: .243 Win. load question

If you use molly coated bullets you can get by with more pressure.

 

[Clark]

Re: .243 Win. load question

If I am loading for someone else, pressure matters.
If I am loading for myself in a strong rifle, brass life matters [the effect of pressure, but who cares how much it took?].

The 243 with larger Boxer primer pockets is going to start getting a loose primer pocket too soon somewhere above 65,000 psi.
The 243 is registered with SAAMI at 60,000 psi max average pressure.

No matter what capricious pressure was registered with SAAMI, the Mauser case head with large Boxer primer pocket has the same strength in any of it's applications; 22-250, 243, 6mm Rem, 250 Savage, 257 Roberts, 25-06, 260 Rem, 6.5x55 [US brass], 270, 7mm-08, 7x57mm, 280, 300Sav, 308, 7.62x51mm, 30-06, 8x57mm, 338F, 358, and 35W.
The strong rifle is several times stronger than that, so the primer pocket is the weak link.

Rather than wait for primers to fall out, and then change my loads, I measure the extractor groove with dial calipers before and after firing. I do this in a work up. The max load is a safety margin below the first measured increase.

If I am finding a load for myself in just one rifle, that safety margin will be a grain or two.
If I were writing a load book with a lawyer editor, the safety margin will be 5 or 6 grains.

What does it all mean?
The load book is a one size fits all recipe, designed to not make the primer pocket get loose with too few firings in a million different guns.
But the advanced handloader can fine tune a load for his gun, get some more performance, and still not let the primers get loose with too few firings.