Gunsmithing Dye to identify wear points?

[upjeeper]

My new ptac bolt carrier group doesn't cycle cleanly. I forget who, but someone posted an ar bolt slick up how to, I think I'll give that a shot.
Aside for the obvious of looking for tooling marks and burrs what's a good way to identify what needs to be smoothed out? I was thinking of a very light misting of white spray paint, letting that dry, then cycling the rifle a couple hundred times to see where it's wearing. Or maybe layout dye?

Any suggestions?

 

[ZombieMonkey]

Define "does not cycle cleanly." Sure, you could use layout die if you rally were interested, but unless there's anything overly obvious why bother? And if it really is that bad, send the carrier back to the manufacturer.

 

[upjeeper]

Define "does not cycle cleanly." Sure, you could use layout die if you rally were interested, but unless there's anything overly obvious why bother? And if it really is that bad, send the carrier back to the manufacturer.

when charging it is not as smooth as i feel it should be. i know this is subjective but compared to other rifles it is just not as smooth.
i can't send the BCG back to the manufacturer, this is the one i had drilled and tapped for side charging. i didn't think i should have to function check a new mil spec BCG before sending it out for additional work

 

[scottyr44]

Dykem makes a hi spot bluing which i use to use for lapping and fitting while tool making might help.

Sent from my SCH-I605 using Tapatalk

 

[geodavis52]

Prussian Blue works, but a cheaper and less messy solution are different colored sharpies..red , blue and black all work great.

 

[Gunfighter14e2]

Prussian Blue works, but a cheaper and less messy solution are different colored sharpies..red , blue and black all work great.

Prussian Blue, via a Q-tip has been my favorite, when lapping anything.

 

[Elite_KG]

I've used a permanent marker. Color the entire area, reassemble, cycle and remove. Inspect for areas the marker has been rubbed off. May help you in a pinch.

 

[Bender]

Does anyone "candle" parts for fitting? Light covering of smoke from a candle is how old school gun makers fit parts....just an idea.

 

[pinsandpitons]

Silly question, could it have something to do with the drilling, taping and side-charging? The feel of it I mean? Perhaps a little binding where a normal charging handle pulls straight back?

 

[upjeeper]

Silly question, could it have something to do with the drilling, taping and side-charging? The feel of it I mean? Perhaps a little binding where a normal charging handle pulls straight back?

it does put a moment on the BCG. The smith who drilled and tapped the BCG did make a knob, but it's longer than i'd like. I'm going to either have a new one made or cut it down myself.
I've checked, and even with the standard charging handle it is not a smooth action

 

[finefire]

Does anyone "candle" parts for fitting? Light covering of smoke from a candle is how old school gun makers fit parts....just an idea.

Tried it...once. A real machinist told me "candling" is pre-dykem. I found it difficult to get consistent coverage with the smoke.

 

[bptactical]

Tried it...once. A real machinist told me "candling" is pre-dykem. I found it difficult to get consistent coverage with the smoke.

Dykem or Sharpie for metal to metal is hard to beat.
But it won't hold a candle to soot for inletting metal into wood. It is not greasy like inletting black, lipstick or Prussian blue so clean up is much easier and you don't stand the chance of staining a stock.
I will frequently soot metal part fitting though, the soot is quicker to apply and you don't have to worry about it getting everywhere
Cheap lamp candles from the surplus store work great for me.

 

[Manocles]

I found this customer review on the Palmetto State Armory site:

"stiff to put bolt in or out in carrier, but i polished it with my dremel tool and presto runs perfect. the finish wasnt the best but all in all id have to say the bolt is a well made piece. functions perfectly. such a good buy i bought 3

(Posted on 2/13/2014)"

 

[diverdon]

Dykem makes a hi spot bluing which i use to use for lapping and fitting while tool making might help.

The Dykem is a great product. You spray it on to the part like spray paint. It dries very quickly and is very thin and scrapes off easily thus you can see where anything touches. When done the part can be easily cleaned with alcohol.

Prussian Blue works, but a cheaper and less messy solution are different colored sharpies..red , blue and black all work great.

When I used it Prussian blue went on much thicker and never dried and was not easily removed. It would be harder for me to see where Prussian blue had been removed. I always used Prussian blue on the mating part and used red lead on the part I wanted to grind, then ground the blue marks off the red lead. For me it was a messy process I do not see how it could easily be used to identify rub marks on precision parts. While it is water soluble it is a pita to clean up.