Sometimes over thinking something can be worst than the potential damage

I have built many lowers in the past and always wrestled with the bolt catch roll pin and front take down pin.   The front take down pin is now easy and it takes me about 5 seconds to do that one, just a small needle nose to hold the detent in place and use the take down pin to compress and roll it into place.  


In preparation  for putting together a high end lower, I was worried about the bolt catch roll pin and it dawned on me, did not have a roll pin starter so I found a Craftsman pin punch the same diameter as the roll pin, and used electrical tape to tape the pin and punch together and two taps from the small ball peen hammer and the pin was started.  No pin stater, no fretting.  Worked perfectly

Bronc

I use a hammer and a needle nose plier.  I squeeze one end of the roll pin so it starts easier.  Might have to spring for a set of roll pin starters one day bu this works fine.

Knipex pliers. Works similar to an arbor press to install the roll pin. Also great for the trigger guard.

I tape the side of the lower with blue tape, use a roll pin starter to get the pin in the hole, don't go into the channel.
Then install the catch, spring and rod and drive the pin the rest of the way with a long punch.

I hold the pin with needle nose pliers while I press it in with vice grips, one I get it started I put down the needle nose and use that hand to hold the bolt catch in position. I press it in a little, give the adjustment screw on the vice grip about 2 turn, go again, repeat untill it's flush.

For the trigger guard and bolt catch roll pins, three hands, a tiny pair of hemostats and a punch.  Wife provided the 3rd and occasional 4th hand on last build.

For the front take down, I use a knife blade (has to be super thin, razor knife works well) or a piece of shim stock or a flat feeler gauge to push spring/detent in.  If you picked something thin enough, the pin will just slip right by....

All very good methods to install...I did use blue tape (blue tape is one of my favorite tools these days) to protect the lower.

After reading the replies, I went on Youtube and there are a number of ways to install the pins and catches, including the ones that are listed above, so all good methods.

For the trigger guard I use a Wheeler Engineering tool that makes the installation easy and also protects the small ears on the lower.  I use nothing but Magpul aluminum trigger guards these days on lowers that do not have a solid built in or enhanced trigger guard already.  The did purchase a Geissele trigger guard for one of my rifles, but find the Magpul is just as good (I think it was a Geissele, I need to verify)

Once your system and short cuts are set up, the rest is easy.

I have some more lowers to build up, purchased a stock pile way back when PSA had them for $29 and free shipping.  This one I was working on was a Larue that I got with a Larue Ultimate Upper kit.

Thanks and stay safe,

Bronc

Hammers are not necessary to build a lower.  Channel locks (I use Knipex) for roll pins and I made a tool for the front take down detent.  My last build was an SLR B30 lower.  Easiest one so far.  The trigger guard is integral and the bolt latch is held on with a set screw.

I bought the KAK (Walt's Tool) Bolt Catch Tool for $10 at Midway.  I used it exactly one time, and it worked as expected without marring the lower receiver.  I never used it again because all the lower receivers I bought since then were billet construction with the threaded bolt catch pin.  But I'll keep the tool handy as I expect I'll be using it again in the near future.  Everyone above has already given you legit options on how to install bolt catch roll pins, so this is just another.

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This.  I tape the jaws so it doesn't mar the lower then just press the pins in.  Best method I've found.

Tape up lower.

Polish one end of the pin with emory cloth.

Tape up vice grip jaws.

Start pin with tiny jaw closure.

Tighten vice grip and repeat.

Of course put the catch, pin and spring in at appropriate time.

Works great and no scratches.

I did the tape and channel lock (or vise grip) thing for years. Switched to an auto hammer a couple years ago. Uh-Mazing.

Use a small battery powered impact hammer and a pointed scribe/centerpunch to drive roll pins. Have you ever seen how an impact wrench can get off seized/stuck bolts versus a hand ratchet/wrench without snapping them? It's kind of like that, except it's an impact ham it taps lightly and very rapidly - so much so, the intertia of the lower itself is enough to drive against. Meaning you can do it in your lap and without ever chucking the lower up in a vise and marring the finish. No taping, vising, clamping, swinging, or squeezing anything. Hold the roll pin over the hole, hold the pointed punch on the roll pin, and then pleace the back of the punch in the autohammer head - apply light pressure with the hammer and the roll pin slides in. The pointed punch makes sure it doesn't pop off the roll pin. It's even gentle enough to install the trigger guard roll pin with no support without breaking the trigger guard pin ears off the lower.  It's pretty good at installing front sight taper pins too.  Plus it's handy for driving nails around the house and shop (what it was actually designed for).

I've done probably a dozen or more lowers and of all my AR assembly tools, it's right up there with my magpul armorers wrench and geissele reaction rod.  

Best Armorers Wrench: Magpul Wrench
Best barrel installatino acessory: Geissele Reaction Rod
Best roll pin installation tool:

Here is a tip nobody mentions.  When putting in the roll pin in the bolt catch, you don't need three hands, you just need to work smart, not hard.  Hold the bolt catch, plunger, and spring all in place with a takedown/pivot pin detent.  First start the roll pin, just barely, and if you're really smart, use the coiled roll pins, not the split one, they go in much easier, hold just as well, and are easier to remove later if need be, then assemble the bolt catch assembly and hold everything in place with the detent.  Then drive in the roll pin with a roll pin punch.  Tape up the receiver first just in case you slip, two or three layers of blue tap in the areas you are likely to slip/ hit, including the area where you are hitting the roll pin punch.  Be sure to put a finger on the back side of the roll pin hole so you don't send your detent to parts unknown as you drive in the roll pin.

Some labor intensive methods and special tools in here. All work, but I just strip a bit of wire insulation and slip it over the end of the punch. Leave some hanging off and that is where you put the pin to hold it in place for starting.

@tobycreek

Damn good, now got me thinking....wire shrink tubing, heat it up and no movement of the pin on the end of the punch

Thank you

Blaspheme

Somewhat true.  First time I built one with the help of a friend while at the range, used a big azz wrench.  

smooth jaw channel locks work well

$11 Irwin version

Here's another vote for the vise grips method, both for the bolt catch and the trigger guard.  I've done it on two lowers now, and it's worked great both times.  

Hope I didn't just jinx myself for #3...  

Just installed another one a few minutes ago.  Using the punch and tape method.  Also took a piece of coat hanger, cut a piece about 5 inches long, bent one end about 1/2", made an "L" and used this as an alignment pin for the bolt catch.  Punched the roll pin in and it pushed the alignment tool out.  Took all of 2 minutes

Bronc

I use a similar approach, but instead of a piece of coat hanger, I use a slightly smaller than the hole drill bit.  Lightly tape it in place, then roll pin starter punch, and then roll pin punch.  Frequently, Midway USA has their AR Stoner brand roll pin punches and starter punches set on sale for under $20.  It's money well spent, as you get starter punches for all of the AR roll pins, and the roll pin punches are decent - not as good as my snap-on set, but not as readily bent as the sets that are always less money.

I bought this some years ago and have used it with great success on a number of builds.

@AL_Safety
@Another-Bill

Thanks for the feedback

That is the one I was looking for, saw it in a video, but searching Brownells site did not turn anything up....

For the drill bit, I did see the diameter is .093" and the video I saw was using both a drill bit and some .093 welding wire.  

Thanks,

Getting the roll pin in is the easy part... removing it gets more interesting. I bought these to do both and also use blue tape.  
https://www.wheelertools.com/ar-tools/ar-bolt-catch-install-punch-kit/710906.html#start=1

This is the easiest tool for the bolt latch pin

Click me

@Nemsis

I am going to IM you my mailing address so you can send me $18 for the money you forced me to spend....

Don’t look at his gas block tool