Hey, this isn't super AR-15 specific, since it applies to all guns, but does anyone have a good video on how to NOT mess up a roll pin?

What kind of punch are you using? Get a Grace set that has the nub on the front that fits in the roll pin hole. This prevents the "mushrooming" effect. Lubrication also helps.

Yeah, I got that. I was working on a roll pin and I started with the cup starter, moved to a roll pin like you mention, and squished it.

Gun oiled it and the hole. Still squished.

Wrong size pin, hole out of spec ?  Just thinking out loud.

I leave the cupped starter on for as long as it'll fit (until just before it comes in contact with the weapon) before I swap to the roll pin punch.
I always use a slightly smaller diameter punch in from the other side keeping the parts lined up, and let the pin drive it out.

As you mentioned - lubed up pin.

Don't spend your time tapping it in lightly, use a few well planned/aimed whacks.

Two things will generally lead to a mushroom:
Tapping it over and over will help induce the mushroomed end.  
Naturally - the holes MUST be lined up, or whacking it into parts where the holes aren't lined up will be the issue, which is why you want the properly sized punch inserted from the back side.

Chuck in drill. Sandpaper the first quarter inch. Oil. Good roll pin starter punch. No mar pliers. (Knipex)

Maybe I have not had enough coffee... but what pin on an AR is over 1/4 inch long?

Trigger Guard Roll Pin, Forward Assist Roll Pin, etc.

Squeeze them in with channel locks is the easiest. I did have one lower that too much anodizing in the trigger guard hole... I used a file on the roll pin (the end I used to start the pin) and managed to get it home.

Replace with coiled stainless roll pin.

Use a starter punch and correct sized roll pin punch.

Attached File

I use a vice to push all the pins in. All of em.

This! The first time I tried. Wow! That was way to easy.

+1, this is the proper method. You should also take the appropriate size numbered drill bit and run it through the hole by hand or using a pin vise. That will clear any finishing materials out of the hole. If the bit tries to bite in, stop, you're a size too large. You can also spin, by hand, a small counter sink bit just to relieve the edges slightly.

I have been putting my roll pins in a vise and lightly clamping them down with the open edge side pointing up so it's visual, not that it would matter much either way.  Then I take a light file and go around it quickly just enough to get the finish off it, then take some 100 grit or whatever sandpaper and go around it a couple times and then a lighter grain sandpaper or steel wool around it a couple times.  Only takes about a minute or two and then your roll pin will go in very easy with just a little bit of lube on it.

I used to put them in without doing this first and sometimes it was a real pain in the ass, other times not so bad.  After I started doing this I decided to keep doing it on all of them going forward since it makes it so much easier to install.

I may have to try the channel locks out as well in the future since some members are recommending them.  Any specific size or type?

I use these:

Lowes compound self adjusting pliers

The pliers method is the best, just use leather, tape or whatever you have to protect the anodizing.

And just for clarification, the pins you guys are calling "coil pins" are actual roll pins; the split pins we use most of the time just wound up being called roll pins in common use as well.

There are a couple lowers on the market that have negated the need to use roll pins at all. They use threaded pins and with a dab of purple loctite, you lose the need to work about mushrooming anything. Just a thought. But all the advice given is solid and all works. Sometimes you just get a tough one.

I tape around the lower to avoid marking it with the hammer then use a brass hammer to tap the pin flush with the hole flush I tap it the rest of the way with a roll pin punch no more mushroomed roll pins.

Here's a size chart for ya

01) A1 Rear Sight Wheel Retaining..........................................1/16x1/4
02) Forward Assist Pawl(round)..............................................1/16x1/4
03) Trigger Guard Detent..........................................................1/16x1/4
04) Forward Assist Pawl(teardrop)..........................................1/16x5/16
05) A2 Rear Sight Windage Drum.............................................1/16x3/8
06) Ejector..................................................................................1/16x3/8
07) Charging Handle Latch........................................................5/64x5/16
08) Gas Tube..............................................................................5/64x5/16
09) Unknown Type Sling Swivel.................................................3/32x3/8
10) Bolt Catch.............................................................................3/32x1/2
11) Forward Assist Pawl............................................................3/32x1/2
12) A2 Rear Sight Elevation Housing.........................................3/32x5/8
13) Forward Assist Retaining.....................................................3/32x5/8
14) 601/XM16E1 Buffer Pin Retaining Pin Retainer.................3/32x7/8
15) Type A-D Stock Swivel Retaining..........................................1/8x7/16
16) 601/602 Front Sight Base Sling Swivel Pin..........................1/8x1/2
17) Trigger Guard Pivot................................................................1/8x5/8
18) Buffer Pad Retaining..............................................................1/8x3/4
19) Type A-D Stock Swivel Bracket Retaining.............................1/8x7/8
20) Unknown Type Sling Swivel...................................................5/32x5/8

I believe he is referring to the bolt catch roll pin and the trigger guard roll pin.  I use calipers or a micrometer to measure the roll pin, then squeeze the pin in a vise to press in down a few hundreds of an inch  (3 to 5) before trying to insert (the roll pins are spring steel and will return to full diameter in short order).  I also use clp or other lube on the pin and in the hole to make installation smoother.

ymmv

Of all the methods I've seen over the years, the drill chuck and turn method works the best for me.

I use a file that I rake over the spinning pin at the angle I want to get it started.

Use long strokes with the file in the direction that the teeth cut.

It's very fast to get pins started that way.

The pliers and vice methods are very likely to damage the anodized or Cerakoted finish on the lower.

Another relatively unknown method is the snap tool spring-loaded punches.

I've been messing with these things since the 1980s, picking the minds of older guys who were old back then through the present.

It's always interesting to see different approaches from different people, but this aspect of assembly isn't rocket science.

Never damaged a lower with the right set of plies, the ones I use, I dipped the ends of the jaws in liquid electrical tape and they have held up real well.

I did however use a punch and hammer a few months ago and broke a trigger guard ear off.

Ouch......

I've never had much trouble with roll pins, I have a punch set and a pair channellock pliers seems to work a hell of a lot easier with no mushrooming.