Is this a cratered primer?

[earthquake]

The web is 0.468" before firing, and 0.471" after.

 

[4O6shootist]

The web is 0.468" before firing, and 0.471" after.

I'd say your chamber is highly oversized at the base. Most Dasher reamers are 0.471 at 200 line. If your ocd brass is coming out that size, there's issues with chamber fit. All my fired Alpha BRA and GT is below 0.470 at base measuring fired case.

 

[earthquake]

Well I loaded up 39 rounds with 31.4-gr Varget and went to the range yesterday. I had zero issues with hard bolt lift. First round hits out to 950-yds.
MV Ave 2,850-fps
ES - 15 fps
SD - 4.5 fps

Not bad for an 18" barrel!

Damn thing shot lights-out. I give up.

 

[lash]

Well I loaded up 39 rounds with 31.4-gr Varget and went to the range yesterday. I had zero issues with hard bolt lift. First round hits out to 950-yds.
MV Ave 2,850-fps
ES - 15 fps
SD - 4.5 fps

Not bad for an 18" barrel!

Damn thing shot lights-out. I give up.

View attachment 8144167

31.4-31.6 are gold at 2850 in my book.

 

[David Lepley]

When you chopped the barrel you lowered the pressure threshold on your charge weight curve, all other things equal. Whatever charge weight you were using (32g) was within acceptable pressures at 26” but is now excessive at 18”. Back off 1.5g or so then work back up in .2 or .3g increments.

Can someone explain the physics here? At some point before the bullet reaches the 18” mark Pmax from 0”-18” has occurred, what ever happens after that is irrelevant, otherwise 26” would be worse not better than 18”…

Or is this a joke and I’m the fool?

-Dave

 

[msgriff]

Can someone explain the physics here? At some point before the bullet reaches the 18” mark Pmax from 0”-18” has occurred, what ever happens after that is irrelevant, otherwise 26” would be worse not better than 18”…

Or is this a joke and I’m the fool?

-Dave

The person that made the claim never explained his reasoning or provided any data/proof.