Below is a pic I took at the prop shop I work at (35years). The reason this was sent in was because the prop was sluggish in operation. The reason for being sluggish is that the fork that connects the pitch change rod to each blade pin, is not designed to go through all that grease in the center of the hub. There should be an airspace in the center of the hub, not all that grease in the picture.
See Hartzell Owners manual 115N and click on the link and go to page 6-7. All the instruction for prop lubrication, of a Hartzell "Compact" propeller, you need is there on the web for your enjoyment.
https://hartzellprop.com/MANUALS/115N-0000-A.pdf
A few things here. A propeller is a giant centrifuge that tends to separate grease back into the stuff it is made from. Mainly a waxy type thickener and oil. I like the old Aeroshell #5 that we used for decades in props. I do not like #6 that has been the factory prop fill for a while. Over the years I have seen many props with Aeroshell #6 in them that have the grease separate during operation. The blade seals are designed to hold grease, not oil. Then typically the oil from the grease tends to leave the prop (through the blade seals) and leave the waxy thickener behind. So the thickener is not a good lubricant by itself and with little or no oil in the mix tends to make for corroded blade bearings ($$$). This is just my observation over the years. Hartzell now uses a factory fill with Nyco GN3058 grease, which in theory will be even better than the #6 and #5. I'm sure Harzell has tested the Nyco. I like that they are willing to go to a potentially better grease. Jury is still out on the Nyco as I've not seen one come apart yet. I do like that the Nyco is an anti corrosion grease we have used on other static propeller applications as an anti corrosive grease (Good stuff). The USN has even gone to great lengths to come up with a spec. for corrosion inhibiting grease (MIL-PRF-32014A).
When pumping in the grease, poke out the wax thickener that has most likely plugged the opposite zerk hole that you have removed (either the zerk or plug as the case may be). Use a piece of safety wire or something similar.
Insert/apply grease to each Zerk until grease comes out the other side,
or until you have pumped approximately 1oz of grease (Approx 6 pumps/strokes on most grease guns). If you are unsure of how much 1 oz of grease is, or looks like, pump some out onto a paper towel on a cheap scale and count the strokes needed for 1oz.
Aeroshell #5 and #6 can be intermixed, per Hartzell. You are supposed to placard the aircraft restricting operation below -40°F if there is any Aeroshell #5 in the prop. I have to be honest, I've never seen that placard on any aircraft and there are thousands of Harztell props that have been lubricated with Aeroshell #5 over the decades.
This is what happens when you just keep pumping grease into the hub: