I finally got everything together to start my lower build.  I started last night and was frustrated by how difficult it was to get the bolt-catch pin in.  Watching the videos and it appeared the pin should just tap right in without much effort.  I found myself hammering at it with the punch/hammer for a while before I was able to muscle it in.     Know it's an open ended question, but what was I doing wrong?  Is there anything I can do to make it easier?

 

You can take a pliers and crush the end of the roll pin slightly, that should give you enough of a taper too get it started easily. What LPK are you using? I never had an issue with a Daniel Defense parts kit.

http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/bolt-tools/dissassembly-tools/bolt-catch-pin-punch-prod26484.aspx

 

Makes the installation of that particular poll pin much easier. Just put a piece of masking tape on the lower under where the punch will slide so you don't mark the lower up.

If you intend to use just a hammer to insert the roll pin, getting it startrd is the key first step.

A roll pin starter punch has a hollow end to hold the pin while you tap the punch as far as it will allow you.

Then switch punches to the one with the dimple to finish the job.

 

The first lower I assembled (before I had roll pin punches) I used a pair of needle nose vise grip pliers to push the roll pin in a number of steps.

To get it started, I slightly closed one end of the pin so it was smaller than the body diameter of the rest of the pin.

Yes, I know I compromised the pin, but only 1/8" worth.

don't forget to wrap electrical tape around the jaws of the vise grips.

 

And use some painter's type tape on the lower so you don't scratch it up with either the punches or the vise grips.

You can always finish setting the pin the last fraction with a standard punch without buggering up the end of the pin.

Putting a drop of oil on the pin doesn't hurt either. 

I like to compress the pin a little as well as use some lube on both the lower and the pin.  

 

Earlier in the year, there was a rash of bad bolt catch roll pins that was released by one of the larger sources for this particular part.  While the OD was fine, the pin was too thick and wouldn't compress properly during installation resulting in exponentially higher amounts of force needed to install them

I invested on a set of roll pin starters and roll pin punches and it makes a HUGE difference. Absolutely worthy.

My preferred tool for starting the pin is a small plastic hammer and a pair of needle nose pliers.  Once the pin is in the hole and able to stand on it's own unsupported, I use the back end of a Geissele roll pin starter tool to finish installing the pin.  Works great.

I invested on a set of roll pin starters and roll pin punches and it makes a HUGE difference. Absolutely worthy.

That's the thing. I have the starters and punches and it still took quite a few whacks to get it in. That's why I think I was doing something wrong.

That's the thing. I have the starters and punches and it still took quite a few whacks to get it in. That's why I think I was doing something wrong.

Then it may have been a hard pin... Like others have said compressing the tip with pliers and a drop of oil helps a lot.

Sometimes the tolerances between the two work out that way. You can always try a different pin from a different manufacturer if you want, I just apply force, in a gentle way. 

I have found excessive coating build up in some lowers.  In my experience the pins are standard and OK.

Poly or forged/billet lower? I have built 2 poly lowers and both had out of spec holes. Even theag catch had to be dremeled on both to install the catch.

It was a PSA LPK w/Mega lower.  This is my first build and really first time working with pins/punches etc.  It took 45 minutes or so to get the pin in, which was frustrating after watching the videos where it seemed to glide in after 2-3 whacks..

 

How much difference does using the correct size punch make?  Does the punch have to be dead on with the pin/hole?

 

Will try oil and/or crimping on the next one to see if that helps.

If you use a punch too small, it'll actually slip inside the roll pin, and expand it, making it more difficult/impossible to get in.

Run a punch of the same size as the roll pin through the holes in the lower first. If it slides in easy your GTG. If not, a little tweeking of the holes maybe necessary.  Happen to me on a couple of builds I was helping a friend with.  After than worked out OK.  I also run a punch in from the opposite side to hold the catch in alignment while sending the roll pin home.

Run a punch of the same size as the roll pin through the holes in the lower first. If it slides in easy your GTG. If not, a little tweeking of the holes maybe necessary.  Happen to me on a couple of builds I was helping a friend with.  After than worked out OK.  I also run a punch in from the opposite side to hold the catch in alignment while sending the roll pin home.

 

T- You are obviously a man with a mechanical aptitude. The use of a slave pin is always the accepted practice when assembling anything that needs a pin fitted. Alignment of a tension pin is imperative. Roll pin holding punches make life and alignment much easier.  The use of vise grips to install a pin is frowned upon. Tension pins have the end beveled for insertion and "crunching" the end should not be necessary. I am VERY hesitant suggesting reaming the hole for the bolt catch but as I said before some are undersized from excessive coating material in the hole.

I even use slave pins then assembling hammers and triggers.

 

I am not saying that assembling a lower is difficult but based on some of the questions and problems that I see, not everyone should tackle it the first time alone.

Thanks all.

I had used a pun holder until the pin was most of the way through the first ear of the lower. That seemed to go pretty well. When I swapped the the punch I also had a slave pin on the other side. My hits weren't moving the pin but were knocking the slave out. I was also using a punch that was too big and a mallet so maybe that was one cause.

 

I'll fully admit in new and doing this alone. Hence the nOob questions.

May have had a bad roll pin. Wrong OA diameter, bad roll,  etc.  Micrometer would have proved this, but then I don't expect you to know, or do this.  When parts are delivered and put in the bins at the factory anything can happen.  When something doesn't go as easy as expected, then you have to question everything and eliminate the possibilities one at a time.  Even then sometimes it don't work.  I have gone out to the local hardware store to source a common part.  Cannot find it right now but there is a reference site that lists the specs on all the small parts. springs, pins, etc.

It was a PSA LPK w/Mega lower.  This is my first build and really first time working with pins/punches etc.  It took 45 minutes or so to get the pin in, which was frustrating after watching the videos where it seemed to glide in after 2-3 whacks..

 

How much difference does using the correct size punch make?  Does the punch have to be dead on with the pin/hole?

 

Will try oil and/or crimping on the next one to see if that helps.

Mega actually specifically advises against the use of PSA LPKs with their lowers.  

Mega actually specifically advises against the use of PSA LPKs with their lowers.  

 

I'm sure you have much more exposure to such information but why do they say that?

Tape off parts of the lower (electrical tape works great) tap it in slow and get it started, then use pliers or needle nose.

Like what everybody said, but

 

DO NOT HESITATE TO USE "YouTube" MAKE IT YOUR BEST FRIEND.

I'm sure you have much more exposure to such information but why do they say that?

I don't know why Mega advises against PSA LPKs.  If I were to speculate based on my own experiences and what I've heard from others in the industry, it's because the quality isn't all that great on their LPKs.  

I don't know why Mega advises against PSA LPKs. If I were to speculate based on my own experiences and what I've heard from others in the industry, it's because the quality isn't all that great on their LPKs.

I saw mention of a warning with their ambi lowers. Hadn't seen the same thing with their non-ambi ones.

Taper the tip of the roll pin with fine emery paper or better yet, run it along the flat edge of a spinning Dremel cutoff disk. With the taper, you'll easily get the pin started in the pivot block and now can tap it in with a punch and hammer. Personally, I use a set of slip jaw pliers (instead of hammer and punch) to press the pin in.