AR Bolt Catch Spring Plunger doesn't fit in the hole.

[J-Dog]

It seems that the bolt catch spring plunger doesn't fit in the hole in the lower reciever. The spring fits fine, and appears to be the correct size, and the plunger fits in the spring, but the plunger is just a hair too large and won't recess into the hole.

It's an ADCOR lower reciever and an RRA 2 stage lower parts kit. Other parts seem to fit nice and snug, and go together with minimal fuss, but the plunger seems to just not be cooperating.

Could this be due to:
An out of spec plunger? (I've ordered another from Midway, since it's cheap enough and I needed a castle nut wrench anyway so I'll check that when it arrives)

The finish on the lower is just thick enough to cause fitment issues? (If this is the case, whats the solution? I could very gently file away some of the finish from the inside of the hole with a tiny round file, but I don't know if that's advisable.)

I'm talking maybe a few hundreths of an inch here. Just barely enough so that if I force it, it will get stuck. But I don't want to do that since I don't think I'd ever be able to get it out. All the videos I've seen indicate that it should move pretty freely.

 

[jrumann59]

if it is the hole you could file away some of the finish, or see if you have drill bit that fits in the hole with little play and spin it by hand. I ran into this with a buffer detente couple of spins with a drillbit got rid of enough of the finish to make the detente move with little friction.

 

[J-Dog]

if it is the hole you could file away some of the finish, or see if you have drill bit that fits in the hole with little play and spin it by hand. I ran into this with a buffer detente couple of spins with a drillbit got rid of enough of the finish to make the detente move with little friction.

I didnt' think of hand spinning a drill bit. Thanks. Mght try that tonight.

Like I said, it's really, really close, but just enough so that the detent would get stuck and not move freely. Which leads me to believe that it's just the finish, but I thought I'd get some second opinions.

Thanks!

 

[navyis2]

I'd probably just take a fine grit sandpaper and roll the plunger against a surface to remove a small bit, then lubricate well.

 

[J-Dog]

I'd probably just take a fine grit sandpaper and roll the plunger against a surface to remove a small bit, then lubricate well.

Actually, I think I'll try this first.
If I mess it up, I've only ruined the plunger, and not the reciever.

If that doesn't work, I'll try the hand spinning drill bit thing.

Thanks!

 

[navyis2]

if you do think that it is just the plunger too big, let me know. I have dozens of them, if you aren't far from the DC area.

 

[Sticky]

If it was anodized, the finish should not be an issue, cerakoted, perhaps...a little fine sandpaper in the hole ID would probably cure that quickly. I did have a couple spots after cerakoting lowers where the mag release lever was hanging up on a bit of extra coating... a jewelers file and a little elbow grease and they work fine, no bare spots... lol

That hole should be 0.156 diameter, +/- 0.003", so you can always double check it with a 5/32 drill bit (.15625)

 

[J-Dog]

if you do think that it is just the plunger too big, let me know. I have dozens of them, if you aren't far from the DC area.

If the one coming in the mail doesn't work and I can't make it work myself, I might take you up on that. Thanks. I have a feeling it's just the finish though.

If it was anodized, the finish should not be an issue, cerakoted, perhaps...a little fine sandpaper in the hole ID would probably cure that quickly. I did have a couple spots after cerakoting lowers where the mag release lever was hanging up on a bit of extra coating... a jewelers file and a little elbow grease and they work fine, no bare spots... lol

That hole should be 0.156 diameter, +/- 0.003", so you can always double check it with a 5/32 drill bit (.15625)

Thanks for the info.

 

[Fox123]

5/32" drill bit, spin by hand.

 

[J-Dog]

Thankums.
Unfortunatly, due to cell phone drama, I didn't get to play with it last night. Tonight's not looking good either.

But I appreciate the help.

Hi Fox! When I get this thing done, we need to hit the range again.

 

[jrumann59]

As for anodizing the Headdown lower I bought on groupbuy had a crappy finish and the plunger hole for the buffer detente was all boogered up and I used a drill bit to clean it out it was leftover aluminum and anodizing that caused the problem.

 

[Fox123]

Thankums.
Unfortunatly, due to cell phone drama, I didn't get to play with it last night. Tonight's not looking good either.

But I appreciate the help.

Hi Fox! When I get this thing done, we need to hit the range again.

Yes sir, but not till end of June after I get back from Hawaii

 

[J-Dog]

Seems it was the plunger. New one cane today and dropped right in, no problem.
I even got to finish the rest of it.

 

[J-Dog]

Yes sir, but not till end of June after I get back from Hawaii

Right on. Holler when you get back.

 

[Sticky]

Excellent! Glad to hear you solved the problem!!

 

[J-Dog]

Excellent! Glad to hear you solved the problem!!

Thanks!
Now I just have to get it to the range and try it out.