Quickload pressure request for 308 load-- safety first!

[THR4L]

I am concerned about a load and would like to request someone with Quickload to run a pressure check for me before I shoot these out of my rifle.

.308 110 grain V-max
CCI 200 primer
49.7 grains Varget
Federal brass (178 grain)
18" barrel

I am interested in the respective pressures associated with the following COALs:
COAL: 2.705"
COAL: 2.750"
COAL: 2.810"

Thank you!

 

[interlock]

I use quickload. but i won't do this request unless you have carefully worked this load up in your rifle. quickload is not a safety checker

 

[THR4L]

Yes--I have loaded all the way through 50.0 grains with this load at COAL=2.750" and it is still safe IN MY RIFLE.

However, I have not shot 49.7 grains in the short COAL of 2.705" and before I do so wanted to make sure the shorter COAL won't create an unexpected pressure spike beyond what is safe. In fact, I'm curious as to how this lesser charge of 49.7g (but at shorter COAL) compares to the pressures at 50.0 and COAL of 2.750", as the latter has been safely worked up to already.

 

[kelbro]

2.705: 50,770psi
2.750: 48,983psi
2.810: 46,805psi

Well under the 60,191 max reported for that cartridge.

 

[THR4L]

Thank you so much for that data. I was a bit concerned about the shorter COAL spiking the pressure, but am relieved to see that it still shows WELL below max pressure.

BTW--do those pressure outputs take into account the lower case capacity of the Federal brass?

 

[kelbro]

No, they do not. QL uses the weight of a fireformed case full of distilled water to determine volume, not case weight. Even with one grain less capacity than their default of 56gr (which is quite a bit), your shortest COAL calculates out at ~53K. Two grains less is ~56K. Three grains less gets you near 58.5K.

QL is just a tool. To get a reasonably accurate prediction, as with any modeling software, you need good data going in.

With your COAL of 2.81, if your cases are trimmed to 2.000, you only have .110 of bullet in the neck. Hornady recommends 2.74. That's where I would be.

That's quite a compressed load and more neck holding the bullet in is a good thing.

Personally, I would switch powders. I like IMR4064 for 308 loads but I understand the component availability issues going on right now and that many have to shoot what they have.

 

[THR4L]

kelbro--thanks again.

I will double check water capacity before I shoot these, just to make sure the higher mass of the Fed brass isn't resulting in significantly less internal volume.

 

[THR4L]

Just as an update--my Fed brass is showing around 55grains of H20 capacity, so I should still be well under SAAMI specs for 308.