Federal primers?

[okie man]

I just broke into a brick of federal gmm lrp and in both Peterson and lapua 6.5 prc brass. They seat fine in star line 6.5 creedmoor brass. cci benchrest fit fine.but the federal won't fully seat. They will muffin top before they seat. Measured them at.2105 and .1275.

 

[QuietTexan]

The primer cup deforms trying to seat into the pocket?

0.1275" is cup height, or does that include anvil protrusion? Doesn't seem out of spec if that's 0.0045 anvil over a 0.123 cup height.

 

[Critter Picker]

They seat fine in my starline 308 brass, and Lapua. 243 brass. The only problem that I've had in 40 years is finding them the last 2.

 

[okie man]

Yeah, the top of the primer muffin tops out if you try to force it into primer cup. .1275 is total when measured in calipers

 

[GLTaylor]

No problem with Lapua, ADG, Petersen or Rem brass?

 

[okie man]

good thing I have a good supply of both.

 

[Varmint Hunter]

I just broke into a brick of federal gmm lrp and in both Peterson and lapua 6.5 prc brass. They seat fine in star line 6.5 creedmoor brass. cci benchrest fit fine.but the federal won't fully seat. They will muffin top before they seat. Measured them at.2105 and .1275.

I've noticed a particularly tight fit with my Fed primers too. Most of my cases have had the pockets uniformed with the Sinclair carbide tool so I doubt that it's the pockets.