I have shot the Small Rifle Primer CCI 400 (cup thickness .020") and the Small Rifle Magnum Primer CCI 450 (cup thickness .025") out of my NEF with the .25 ACP conversion with no problems. I do know the Large Rifle Primer CCI 200 and Large Rifle Magnum Primer CCI 250 both have a cup thickness of .027". Keep in mind this is also a larger diameter cup so I would hope there would be no problems with the larger firing pin of the SB1 frame.
The slightly thicker cup may possibly cause some primer issues. I have read that large primer pockets for the pistol cases are .118"-.122" deep and the large rifle primer pockets are .128"-.132" deep. My concern was using a Large Rifle Magnum Primer in a pistol case, but the LRP CCI 400 and LRMP CCI 450 are both .118" in height and are they the same diameter as the Large Pistol Primers? Does anyone know if there would be a problem seating the LRMP in a pistol case that accepts the LPMP?
Ultimate Muzzleloading seats the LRMP in the .45 Win Mag case, but I don't know if the primer pockets have been modified or not?
