270 WSM: published maximum charges vs velocity

therifleman556

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Got a new toy to play with recently. Picked up a Browning A Bolt 2 composite stalker in 270 WSM. Came with dies, a fair share of brass, and a half decent Vortex 3-9x50.
Figured I'd give it a chance since I'm trying to go lead-free for deer (personal choice, not political), and I know how lead free designs like speed for optimum expansion. The fact that it fits in a tidy sub 8lb package is icing on the cake if it will shoot well.

Anyway; cut to the chase, right?

I picked up some 110 grain Barnes TTSX just to try out. Barnes' data lists 71 grains of RL19 as maximum in a Winchester case with a gold medal 215 primer @ 2.745 OAL producing 3552 fps in a 24" barrel.

I'm using Winchester cases with CCI 250s @ 2.820 OAL in a 23" barrel.

Started @ 69.0 grains, loaded half grain increments up to 71.0. Here's the breakdown...

69.0 - 3515
69.5 - 3546
70.0 - 3592
70.5 - 3612
71.0 - 3643

There were NO pressure indications until I hit 71 grains, and even then it was just a little more resistance on the bolt handle. The primers looked round and beautiful, with no signs of wanting to crawl into the firing pin hole or any of that nonsense.

Now, I understand that CCI primers are a bit on the hard side and not the most reliable indicator of excess pressure.

Which leads me to ask the experts: do you work up to book maximum and watch for signs, and then back down once you've reached them?

Or:

Do you work up and STOP when you've reached the maximum velocity that published data says you can reach?

All of the reading I've done prior to loading for this cartridge had lead me to believe that it was **** near impossible to obtain velocities that are published in manuals. But here I not only reached it, I blew it out of the water using their listed charge weights.

What gives?

BTW: here were the first two shots @ 100 yards, 69.0 and 69.5 grains
2500.jpeg
 

MagnumManiac

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Feb 25, 2008
Messages
3,150
I take published velocities and maximums with a grain of salt.
You have done exactly what I do, regardless if I exceed book velocities or not, I let my rifle tell me what maximum is.
I often get higher velocities than what’s published, but the opposite is also true.
If you have a tight chamber/bore you will get higher velocity at LESS powder than a loose chamber/bore combo. Also, if you have a long throat, you may get higher velocities and higher max charge weights over a short throated rifle.
There are so many variables that alter the outcome in rifle loading, hence the need to work up your loads.
Remember, loading manuals are a guide, not a recipe book.

Cheers.
:)
 

Mikecr

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Aug 10, 2003
Messages
5,597
Location
NC, oceanfront
Different finished barrels, different bullets, different lots of powder..
It's not a pressure problem until it's first a problem.
 

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