Cotter Pins in a BCG

KnotRight

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I have one hell of a time trying to get the pin back into the BCG after cleaning it. No problems with a new pin. This there a trick to get the old pin back into the BCG? I tried turning it and it still will not go.

Also, does anybody have a place to order the pins in bulk?
 
If it’s not seating properly, I’ve helped them into place with a small punch from the middle/rear opening where the pin is visible. Sometimes they open up too much and you can’t get them back into place and you don’t have a spare on hand

That KNS pin looks like a good option for a BCG that keeps opening up cotter pins
 
That’s what she ...
lulz
as Pink_Vapor mentioned, it slips in easier if it's got a good taper at the tip
And if it's just bent, maybe you can look at having it straightened

I had one that had such an aggressively open tip that i had to jam something inside way back up to the base and crank on it until it was back into a shape i could work with.
 
I've found the trick for me is to not look down from the top of BCG while installing pin.

Instead, if I look at bolt face towards the back of BCG, I can see that I am canting pin down slightly and quickly line it up and it slides right in. This after many times of wanting to pound it in with a 5lb sledge! Saw this on a video and it helped me.

Give it a try. Maybe it will help.
 
make sure your firing pin isn't slightly back in the bcg also helps. It's also a .02 cent part if you buy 100 spares :D
 
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Take it in and out a half million times cleaning it and it’ll go in every time! That advice works for more than cotter keys! Jus sayin...
 
I took one of my ARs out today and this is the first firing of the gun since I installed the KNS pin and after 75ish rounds the pin was backing out and locking up the bolt. Has anybody had this problem?
 
I took one of my ARs out today and this is the first firing of the gun since I installed the KNS pin and after 75ish rounds the pin was backing out and locking up the bolt. Has anybody had this problem?

ONLY if it has been installed backwards which is usually the case with the first round fired
 
Personally, I’ve never had a problem sticking it in.







O.....M.....G...... this thread is KILLING ME!!
[emoji16][emoji16][emoji16]

To the OP, your post is legitimate, and I hope your questions are answered, but when you post a thread around here talking about sticking something in a hole....[emoji23]

“Try spitting on it”......shit!!![emoji1787]


Sent from my iPhone using Tapatalk
 
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Called KNS Precision today and they said that the pins were made for the Colt BCG and that others manufactures might have a larger pin hole which would let the pin lock up the bolt after firing. On that note I went by Grainier Parts and ordered some 3/4" cotter pins to see if they would work. 100 of them for around $3.75. They should be in on Tuesday.
https://www.grainger.com/product/5U...657acf431c32e0f0f8e0a63550f9f5a7fc877150e79ba
 
Called KNS Precision today and they said that the pins were made for the Colt BCG and that others manufactures might have a larger pin hole which would let the pin lock up the bolt after firing. On that note I went by Grainier Parts and ordered some 3/4" cotter pins to see if they would work. 100 of them for around $3.75. They should be in on Tuesday.
https://www.grainger.com/product/5U...657acf431c32e0f0f8e0a63550f9f5a7fc877150e79ba
That's make me :mad:
Their website says nothing about Colt BCG, "Replaces standard cotter pin found in the bolt carrier to retain the firing pin as in original Stoner rifles."
 
Called KNS Precision today and they said that the pins were made for the Colt BCG and that others manufactures might have a larger pin hole which would let the pin lock up the bolt after firing. On that note I went by Grainier Parts and ordered some 3/4" cotter pins to see if they would work. 100 of them for around $3.75. They should be in on Tuesday.
https://www.grainger.com/product/5U...657acf431c32e0f0f8e0a63550f9f5a7fc877150e79ba

Honest question: what makes these cotter pins better/easier than a cotter pin designed for a BCG?
 
The cotter pins that you get from Midway USA or Brownells are close to $2.00 each if I remember correctly and these were $3.76 for 100.

At that price I hope they work. The $9 pins did not work in all ARs.
 
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Good call on the Grainger pins. FWIW, alot of folks will argue that the cotter pins aren't 'hardened' for firearms use. Seriously. It's a steel pin. It's only job is to retain the firing pin.
You should be inspecting your BCG in your rifle occasionally when you clean it. I do it every time I clean mine. If it looks like it's 'wearing out' then replace it.
 
Called KNS Precision today and they said that the pins were made for the Colt BCG and that others manufactures might have a larger pin hole which would let the pin lock up the bolt after firing. On that note I went by Grainier Parts and ordered some 3/4" cotter pins to see if they would work. 100 of them for around $3.75. They should be in on Tuesday.
https://www.grainger.com/product/5U...657acf431c32e0f0f8e0a63550f9f5a7fc877150e79ba
I don’t need them as far as I know, but I’m tempted to order some just because. I get a discount at work and it includes free next day shipping. I can have those 100 here tomorrow for $3.10 + tax. :eek:
 
The new pins are a little longer which can be trimmed but the are not a thick. Not sure if that matters.
20200225_131710.jpg
 
I wouldn’t trust that thin pin, it might break, or it’s thin enough that the pin might slip out past it. Both scenarios may lock up or damage the receiver.
How much is an OEM pin? I’ve never had an issue with one.
 
I wouldn’t trust that thin pin, it might break, or it’s thin enough that the pin might slip out past it. Both scenarios may lock up or damage the receiver.
How much is an OEM pin? I’ve never had an issue with one.

Pink_Vapor I do not have a problem usually with OEM cotter pins but when I clean the BCG sometimes I can not get the cotter pin back into the BCG. I would like to have a few around the reloading room and a few in the range bag. The KNS pins that I bought were about $7-9 each. Also, over the past 2 range trips, I have seen 2 extractors brake. They were ARs but not in 223 caliber. That got me thinking about having an extractor or 2 in the range bag too. Those are about $21 each.
 
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Pink_Vapor I do not have a problem usually with OEM cotter pins but when I clean the BCG sometimes I can not get the cotter pin back into the BCG. I would like to have a few around the reloading room and a few in the range bag. The KNS pins that I bought were about $7-9 each. Also, over the past 2 range trips, I have seen 2 extractors brake. They were ARs but not in 223 caliber. That got me thinking about having an extractor or 2 in the range bag too. Those are about $21 each.
What caliber are you breaking extractors with?
I haven’t seen that either. I’ve been shooting the same 6.5G 300BLK & 5.56 for 12+ years.
 
What caliber are you breaking extractors with?
I haven’t seen that either. I’ve been shooting the same 6.5G 300BLK & 5.56 for 12+ years.

Russian 45x39 (I think) and 5.7
First time I have ever seen those calibers in an AR platform.
 
@JBoyette if the pin that I bought from KNS (flared on one end) fall out or lock up the bolt how does the cut paper clip stay in the BCG?
Thanks,

So a few things.
The only way a firing pin retaining pin affects the operation of a rifle is in three ways.
1. its installed before the firing pin
2. its too long and protrudes through to hinder the installation of the BCG in the upper.
3. Its not captured on the left side and falls through and out the ejection port when the bolt and carrier is in battery.

For point 1.
I have seen many a person install the bolt, cam pin, FIRINGPIN RETAINER PIN, then the firing pin. This is the WRONG sequence. Its such a big deal DOE had it mandated all Nuclear Security officers under the supervision of a ARMOR perform this test.

1. Place the bolt in the unlocked position.
2. Grab the BCG with the bot facing upwards
3. Tap the rear (buffer side) of the BCG on a table
3a. Did the firing pin fall out?
IF YES you installed the firing pin retaining pin too early remove, install firing pin, install firing pin retaining pin and go to step 1.
IF NO
4. place the bolt in the locked position
5. Place your index finger inside the hammer track and press on the rear of the firing pin.
6. Observe the firing pin protruding out of the bolt

You are complete.


To your question, clip the paperclip at a curve 1/2 way, then trim to lenght not to extend past the body of the BCG.
 
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