300WSM - 190 ABLR - Winner

[MagnumManiac]

Some believe compressed loads can break down the extruded kernels "possibly" affecting ES and SD. I just don't like it for personal reasons.

Many believe this...simply isn't true.
There is no way powder kernels can crush other powder kernels unless extreme pressure were used. More kernels get damaged by the powder measure drum while charging than from a compressed load.
I try to avoid them simply because the bullet can back out after seating...have witnessed this using Retumbo in a 300WM with 200gr AB's and a short OAL that lead to a .050" back out over night, on average.
Had to increase neck tension AND reduce the load to get it stable, in the end it wasn't worth the trouble, couldn't get those ragged one hole groups again with the tweaked cartridge, so I abandoned the whole episode.
If the powder fits now, I will use slightly compressed loads, but if it's too much compression I will try a different powder that takes up less room.

Cheers.

 

[nksmfamjp]

There is no way powder kernels can crush other powder kernels unless extreme pressure were used.

That's an interesting thought. Has it been tested or observed?

I try to avoid them simply because the bullet can back out after seating

Completely agree. I have seen this in my 458 Lott loads. I backed off.

 

[MagnumManiac]

That's an interesting thought. Has it been tested or observed?




Completely agree. I have seen this in my 458 Lott loads. I backed off.

Yep, I compressed a load so hard that the case bulged, pulled the bullet and tipped the powder out, which was H1000, and not a single kernel showed any damage.
Have tested this with ball powder as well, all that happens is the ball powder sticks together and forms a solid mass for about 1/2-3/4 of an inch. It burns just like normal.
It's difficult getting the powder out though, had to use an Awl to pick at it.

Cheers.

 

[Muddyboots]

MagnumManiac: I also don't like heavily compressed loads due to the potential deformation of the bullet secant/ogive area from seating which in my book is good enough reason for me. Even with a right stem there is a lot of pressure. A lightly compressed load is whole different animal from one that you can hear "crunches" the powder where you are putting a lot pressure on the bullet. Another good thought for monos! I wonder if anyone gets to that anymore with seating bullets close to lands thus increasing case capacity?

 

[308ghost]

It may be the powder of choice that is the possibility of avoiding compressed loads. I am sold on RL16 for the 300WSM and it takes far less to get velocity that most. I am using only 62.5 grains of RL16 with the 190 which is far less than most powders. I bet if I used RL26 it would definitely be a compressed load since it is with the 190 Impact. I then switched to RL16 and better load density etc. without compression. I do not like compressed loads so I adjust my powders to avoid them. Unless it is a ball powder than maybe depending upon caliber.

Disclaimer: This is a safe load in my rifle so I have to remind anyone you have to follow proper loading steps to establish a load and not copy anyone else's.

I have a similar load @61.9gr. RL16 with the 190 gr nosler ablrs and nosler brass with 210's. Clocks at 2900 21" barrel. Also shoots the nosler 168 ablrs really well. Possibly even better.