A Question of Shoulder Angles

[jonsidneyb]

I am trying to get a good understanding of the various shoulder angles that are used.

Here is what I think I know so far.

Some shoulder angles are changed in order to get more powder capacity, some should angles are for better feeding, others are for the flow of brass???

Can some one set me straight? I am guessing there is no best shoulder angle but it is all compromises.

What the pros and cons of the verious shoulder angles used in cartridges?

 

[NeilNE]

Shoulder of 30 degrees or less, work best in repeaters, over 30, for single shoot. You are right about brass flow, the sharper the angle the less brass flow.

I personally believe that 40 degree shoulder give better burning rates. In other words, if you have two cases that hold the same amount of powder but one has a 40 and the other has a 20 degree shoulder, the 40 will shoot faster.

 

[jonsidneyb]

6.5/308 Win. Improved,24 deg.)
6.5/308 Win. Improved,28 deg.)
6.5/308 Win. Improved,30 deg.)
6.5/308 Win. Improved,40 deg.)

It was seeing things like this that got me thinking on it and I started noticing how many differet shoulder angles I see. I am going to guess that the angle affect powder capacity as well.

I wonder if the 24 degree angle is for autoloaders.

 

[NeilNE]

I am going to guess that the angle affect powder capacity as well.
**Your are right

I wonder if the 24 degree angle is for autoloaders.
**For autoloader, I think you could go to 28 degree for
reliable feeding. Just a guess.