I was using the appropriate tools, Brownell's roll pin holder and pin punch, yet the end of the pin is now chipped and refuses to go in any further. What are my options at this point?

Shitty iPhone pic is all I have:

Drive out from the other side and replace......or if the bolt catch functions....just trim the end and dab with a little air dry cerakote and no one will ever know....

Drive it out form the other direction with a correctly sized punch. Never use one smaller than the pin. Install a new one from back to front. I have never tried to install one from the direction you did. Roll pin starters are ok for starting the pin but I use a bigger punch than the pin to drive it in up until the very last portion. Thne I swap to the 3/32" punch.

I've done this on three so far and no problems with it.  Just take it easy as you go.

What size pin punch would be best to drive it out? I don't have a set so it's something I'll have to order.

This is the punch I bought:

https://www.adcofirearms.com/itemdetails.cfm?inventorynumber=63

But Brownell's and I imagine just about everyone selling AR tools will have it or something similar.

Drive it in from the back side next time, so if you need to take it out you can buy and use this to remove it if needed. You could probably drive it in with this as well, from the front but I didn't.
http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/bolt-tools/dissassembly-tools/bolt-catch-pin-punch-prod26484.aspx
3/32 is what you are looking for btw, just make sure its long enough to clear the receiver.

That's the one I used.

I know Brownell's sells everything I would need, but I'm not ordering from them. The reason I put the bolt catch on today is because I finally received the roll pin holder after waiting for over a month.

 +1 to this.  You can insert this particular roll pin with an ordinary punch, but to remove one you need the special flat-sided punch.  In the OP's case, the best approach is to remove the dinged up pin and install a new one.  Apply a little grease to ease it into place. - CW

The hole is probably undersized. It happened to me on my last Noveske lower. I drove the pin in from the other side, so removing it is not going to be a huge issue.



You could have an over-sized pin too; is it DPMS by any chance?



To remove mine, I'm going to put some lube in the pin hole and use a heat gun to gently expand the Alu before I drive out the old pin.  In theory it should work b/c Alu expands under heating at a lower temp than steel.



And I'm going to use some alumablack to touch up the scratches b/c that will act like a cold blue and give you a chemically converted surface finish instead of the cerakote, which is obviously a painted finish.



Don't try to just dremel off the extra hanging bit of the pin, though. It will look terrible and you won't be able to live with it.



Go ahead, ask me how I know.  



Upshot is, around here the scratched Noveskes are considered even more tacticool-tools.



FWIW: I'm cerakoting mine at a future date.

I'm thinking the hole is undersized. It's a chainsaw lower I backordered during the panic and I'm just now getting around to building it out. The pin came from a DD LPK, but I ordered a couple DPMS pins from MidWay last night since that was all I could find in stock. Thankfully I'm painting this AR so I'm not too concerned about dinging it up.

Ha. Good call on the paint.



I ordered two different roll pins from Brownells, one DMPS and one High Standard. I'm going to take a caliper to each and the one I remove from the lower (provided she breaks free). It should give me a better sense of what the issue was to begin with.



I'm probably going to use the smaller of the two pins. I may compress the one I choose to use only slightly. And I'm going to try to heat up the receiver again and  drive the pin in when the hole is still nice and warm, using plenty of lube of course.



but the question remains, why couldn't it just be the damn screw you used in the first place, mr stoner!?!







 

This is the method I use, as well. I will say PSA roll pins are always a PITA for me (not sure which pins your using). I've found that RRA pins go in much easier.

drive it in like this