Lefever H 12 Gauge Questions

[Cold Spring]

Woohoo, bonus points!!!! An ejector gun.

All three of my H Lefevers and one I'd sold have nominal 2-5/8" chambers but you'll want to check yours with a good chamber length gauge. Also, a strong suggestion to get the bores and wall thicknesses measured full length and do some consultations before shooting her with anything. Bad things have been done to many shotguns over 100+ years.

[Michael D Hankinson]

Have shot the gun with RST 1oz Spreader loads with 1150 Velocity, Gun weighs 7.25# and with those shells has a very low recoil. This weekend I purchased a box of ELY Grand Prix Paper shells with 1 1/16th oz #6 Shot 2 1/2". The box indicates for guns with a service pressure of 3 Tons, or European proof pressure of 850 kg per sq cm. From what I understand these are lower pressure than the RST.
Are these shooters or collector rounds?