Author Topic: Bren 805 loose rear pin  (Read 920 times)

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Offline GRJY

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Bren 805 loose rear pin
« on: November 05, 2017, 12:15:11 PM »
So I had my 805 s1 out the other day. Shot great. When I took it apart for cleaning I noticed the rear pin isn’t very tight in the receiver when engaged. When it it is pushed through both the lower and upper and the spring engaged on the other side, it is just floating there. If the spring wasn’t there it would fall right out. I don’t think the rear retains much other than help align the stock. Should this pin fit more snug like the front pin? 

I measured the holes on the lower receiver in the front. They measured the same as the rear on the upper receiver. The hole on the bottom rail on the front receiver is about .009 smaller. I am assuming that is why it fits more snug. Can you all please look at the rear pin and see if it is snug or loose?  Like I said, It would literally slide right out if that clip wasn’t on the end of the pin.

ETA what purpose does rear pin serve? Is it jus there to keep the stock from sliding down just Incase the stock retention button is pushed? If that is the case the snugness of the pin shouldn’t really matter, correct?

Also, there is a slight rocking back and forth between lower and upper. Is this normal for this rifle? I have ARs that do this. Just wondering if this is normal for this rifle. Thanks
« Last Edit: November 05, 2017, 02:48:34 PM by GRJY »

Offline GRJY

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Re: Bren 805 loose rear pin
« Reply #1 on: November 05, 2017, 08:42:08 PM »
Anybody care to take a look at their rifle for me. It would be much appreciated.

Offline das boots

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Re: Bren 805 loose rear pin
« Reply #2 on: November 05, 2017, 10:02:19 PM »
I have replaced my Takedown Pins with KNS.  Not a fan of the stock pin. 

Yes, they are very snug.  Hope this answers your inquiry.

"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed." - 2nd Amendment

Offline GeeMan

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Re: Bren 805 loose rear pin
« Reply #3 on: November 05, 2017, 10:54:57 PM »
I also run KNS push-button pins in both of my 805's in place of the OEM's...  no play or slop in them...  quite snug actually...  and I also don't notice any discernible movement between uppers & lowers...  hope you get it sorted out...

Offline wyoung

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Re: Bren 805 loose rear pin
« Reply #4 on: November 06, 2017, 11:14:20 AM »
The factory pins are fine on both of my Brens.

Offline Manticore_Arms

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Re: Bren 805 loose rear pin
« Reply #5 on: November 06, 2017, 12:41:50 PM »
Some pins are snug, some are a bit looser.

The rear stock block is actually held in place by two "fingers" on the back of the recoil spring assembly.  The crosspin is just a "belt and suspenders" in case the stock takes a direct, very hard downward blow to protect the fingers from breaking off- the pin will take the load and transfer it to the receiver.

Pressing the button on the back of the stock block pushes those "fingers" out of the stock block so you can slide it down and off the gun.

You can run a gun without the rear pin installed (not recommened, but you can do it) and the gun won't fall apart and everything will be fine.

Sven
Manticore Arms

Offline GRJY

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Re: Bren 805 loose rear pin
« Reply #6 on: November 06, 2017, 03:18:14 PM »
I got off the phone with cz. They said it sounds fine. The rear pin doesn’t really hold the anything I place. Basically there as a secondary measure to keep the stock from being forced down in case the main latch disengages. The gunsmith said there may or may not be a wobble in the receivers. It shouldnt be as bad as some ARs but it can be there.  The wobble is more in the rear by the grip and less side to side and but more up and down ( it is slight but just enough to make an knock sound if you try and wobble it. Judging by what he said it sounds like my rifle is good to go. Thanks for the replies everyone.
« Last Edit: November 06, 2017, 03:49:17 PM by GRJY »

Offline Czech-m8

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Re: Bren 805 loose rear pin
« Reply #7 on: January 23, 2018, 05:43:14 PM »
I have a slight wiggle in the lower receiver and the upper. It is only noticeable when the bolt is forward. When bolt is locked to the rear the lower tightens up. I believe this is a slight manufacturing defect in the lower that needs to be shimmed. You can correct this by buying a new lower or just putting a small piece of tape on the very back of the lower so that it will hold everything tight.  I haven't done this myself but it would work. Yours seems too loose if it is allowing the pin to come loose. If you want to get a new lower try here: https://shop.cz-usa.com/ProductDetail/370000106560_Pistol-Grip-805 it's only 35 bucks but it's not fde :-(
I did also buy the KNS pins and that dis not correct the wiggle. Just some nicer pins.

Offline armoredman

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Re: Bren 805 loose rear pin
« Reply #8 on: January 23, 2018, 05:50:10 PM »
I checked mine, loose as a goose and not worried. :)

Offline Czech-m8

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Re: Bren 805 loose rear pin
« Reply #9 on: January 23, 2018, 06:31:29 PM »
I'm going to tighten up my goose with some of this tape:

https://www.amazon.com/gp/aw/d/B01N0FC2LO/ref=mp_s_a_1_6?ie=UTF8&qid=1516749811&sr=8-6&pi=AC_SX236_SY340_QL65&keywords=thick+tape+2mm&dpPl=1&dpID=41HzUqQ%2BCOL&ref=plSrch

A small strip on the back of the lower should do it or maybe a small strip on the bottom/inside of the rear stock block

Offline armoredman

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Re: Bren 805 loose rear pin
« Reply #10 on: January 23, 2018, 10:48:57 PM »
Not a bad idea at all.

Offline Czech-m8

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Re: Bren 805 loose rear pin
« Reply #11 on: January 26, 2018, 08:20:41 PM »
Update: using the neoprene tape worked out excellent.  You can trim it and double stack it which I did.. two strips on the stock block and one 2 mil strip on the back of the lower.

6mil of neoprene total and it is as tight as a steel drum. Lots of extra tape left over.

Offline armoredman

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Re: Bren 805 loose rear pin
« Reply #12 on: January 26, 2018, 09:22:05 PM »
Good tip, thank you!