The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: Semi-automatics

Reply
 
Thread Tools
Old June 5, 2013, 01:08 AM   #1
American Red Neck
Junior member
 
Join Date: May 8, 2013
Posts: 81
Found BCM Bolt!!

Found a bcm bolt on gun broker. not exactly cheap but hey i found one/bought it. I also bought a field gauge from brownells. this should be the only gauge i need right? anyways if i put this bolt in my gun now and decide to change the barrel 5000 rounds down the road can i use this same bolt?
American Red Neck is offline  
Old June 5, 2013, 04:24 AM   #2
Palmetto-Pride
Senior Member
 
Join Date: May 31, 2009
Location: Charleston, SC
Posts: 1,824
If it were me I would try to get a new bolt with a new barrel, but yes you could use it. Just to clarify I am talking about the bolt only not the bolt carrier also.
__________________
“The problem with socialism is that you eventually run out of other people's money.”

-Margaret Thatcher-
Palmetto-Pride is offline  
Old June 5, 2013, 06:41 AM   #3
BillyJack3
Senior Member
 
Join Date: May 2, 2012
Posts: 392
Why would you want to take your spare bolt and use it now? From your other thread, it doesn't look like you have any problems with your current bolt.

If you use your new bolt for 5,000 rounds, it becomes a used bolt. Add a new barrel later and you are essentially matching a used bolt to a new barrel. That's not recommended as they wear together. Anytime I get a new upper, I get a new bolt to "match" it.
BillyJack3 is offline  
Old June 5, 2013, 07:16 AM   #4
sailskidrive
Senior Member
 
Join Date: October 26, 2008
Posts: 725
I would function test the new bolt, clean it and put it away away as a spare.

I'm really not sure while so many folks are hung up on BCM parts in general. I have two of their bolts and while they are well made so are 90% of the other mil-spec parts available from various manufacturers.
__________________
SailSkiDrive
Hk USP 45 Expert, USP 40, USP 9, SIG P226, S&W M&P9, Hk 4, Makarov, Desert Eagle 40, Beretta FS92 Centurion, Kimber TLEII 1911A1, Glock 22, SIG P225, 1943 Rem Rand 1911A1, S&W mod 64, Walther PPQ, SIG P229, Browning BDA 45 (SIG P220), Hk45, SIG P230
sailskidrive is offline  
Old June 5, 2013, 09:20 AM   #5
Fishbed77
Senior Member
 
Join Date: November 23, 2010
Posts: 2,421
Bolt carrier groups have become much easier to find as of late without resorting to Gunbroker.

PSA has them in stock now. They are, for all practical purposes, identical to the BCM BCGs, aside from the markings. They likely come from the exact same supplier as the BCM-marked versions. The price is still about $60 higher than pre-election prices, but at least they are out there.

http://palmettostatearmory.com/index...ier-group.html
Fishbed77 is offline  
Old June 5, 2013, 04:47 PM   #6
American Red Neck
Junior member
 
Join Date: May 8, 2013
Posts: 81
So should i just save my spare bolt and use it when i get a new barrel?
It looks to be some hair line cracks in my current bolt lug close to the extractor due to a jam i had a while ago. the lug smashed on a rock completely turning it to dust (the rock) and i am probobly being paranoid but i think there are some hairline cracks on the lug now. The current barrel i have now is the stock sig one with only about 700 to 800 rounds on it. So using the bcm bolt would be no good? Should i change the bolt when i change the barrel. I was gonna check headspace on my new bolt and if it checked out, use it and save the sig as a spare. but i dont want excellerated wear on the semi used 800 round barrel i have.
American Red Neck is offline  
Old June 5, 2013, 08:42 PM   #7
Metal god
Senior Member
 
Join Date: April 10, 2012
Location: San Diego CA
Posts: 1,664
Quote:
So should i just save my spare bolt and use it when i get a new barrel?
Short answer - Yes

Quote:
It looks to be some hair line cracks in my current bolt lug close to the extractor due to a jam i had a while ago
If correct , that would be a reasonable reason to change bolts now.

Quote:
The current barrel i have now is the stock sig one with only about 700 to 800 rounds on it. So using the bcm bolt would be no good?
General rule is
new bolt new barrel OK
new bolt old barrel OK
new barrel old bolt NOT OK ,
old barrel old bolt from different gun NOT OK

The rest of your questions are more of a choice then a need so what ever you want is what you want .
__________________
If you have a problem with everybody .

It's not everybody that has the problem
Metal god is online now  
Old June 5, 2013, 09:40 PM   #8
American Red Neck
Junior member
 
Join Date: May 8, 2013
Posts: 81
thanks for the help. I got a magnifying glass today to look at the lugs a little closer but i cant tell if there are scratches or tiny cracks. i dont want to be shooting and have a lug break and have headspace change then damage even more of my gun or even my self..and i dont have a camera for pictures. if there were cracks the bolt lug couldnt last long could it. this jam happened when i first got the gun and i have fired at least 500 to 600 rounds since then and i dont notice anything getting worse i just notice the lugs polishing more from wear. thats it. dont know what to do but i have a brand new bcm bolt.
American Red Neck is offline  
Old June 6, 2013, 12:13 AM   #9
Quentin2
Senior Member
 
Join Date: June 18, 2009
Location: NorthWest USA
Posts: 1,590
BCM is about as good as it gets for BCGs so you did well. I have two and a Daniel Defense which is good.

PSA is a good source but stay away from their 8620 steel bolt. Right now their Premium PSA logo BCG with HP/MPI bolt is in stock for $189. It should compare to the BCM but I'd go with BCM anyway unless you want the PSA logo on a PSA upper.
Quentin2 is offline  
Old June 6, 2013, 07:15 AM   #10
BillyJack3
Senior Member
 
Join Date: May 2, 2012
Posts: 392
If your current bolt worries you that much, then swap it out. When you get a new barrel, get another bolt. They go for about $60. Since you are shooting 10 - 15 thousand rounds a year, this is pennies.
BillyJack3 is offline  
Old June 6, 2013, 02:14 PM   #11
American Red Neck
Junior member
 
Join Date: May 8, 2013
Posts: 81
I wish there was some way to clarify if i have a crack in my bolt lug or not. i use a magnifying glass and see marks where the lug jammed on a rock but thats about it. i think its just a scratch but im told if i have any doubt in my mind about this bolt i should swap it out. i only have a field gauge, i dont have the go or no-go. is a field gauge sufficient to tell me im good or not?
and if the bolt was cracked from the jam 600 rounds ago wouldnt it have failed by now?
American Red Neck is offline  
Old June 6, 2013, 02:56 PM   #12
Quentin2
Senior Member
 
Join Date: June 18, 2009
Location: NorthWest USA
Posts: 1,590
The field gauge can't tell you if a lug is cracked. If something's wrong it (they) will shear off as your round count goes up. Often there's no warning until a lug comes off.

You really should find a way to post high quality pictures here, as it is now you have it in hand while we can only speculate. Speculating, I'd say nothing's wrong.
Quentin2 is offline  
Old June 6, 2013, 03:32 PM   #13
slim9300
Member
 
Join Date: January 7, 2013
Posts: 72
Found BCM Bolt!!

Quote:
Originally Posted by American Red Neck View Post
I wish there was some way to clarify if i have a crack in my bolt lug or not. i use a magnifying glass and see marks where the lug jammed on a rock but thats about it. i think its just a scratch but im told if i have any doubt in my mind about this bolt i should swap it out. i only have a field gauge, i dont have the go or no-go. is a field gauge sufficient to tell me im good or not?
and if the bolt was cracked from the jam 600 rounds ago wouldnt it have failed by now?
Get a UV dye penetrant kit and do a quick test. You will know right away.
slim9300 is offline  
Old June 6, 2013, 06:48 PM   #14
American Red Neck
Junior member
 
Join Date: May 8, 2013
Posts: 81
dye test results were good no crack. guess i will save the bcm bolt.
American Red Neck is offline  
Old June 6, 2013, 07:10 PM   #15
Metal god
Senior Member
 
Join Date: April 10, 2012
Location: San Diego CA
Posts: 1,664
That's good to hear . Now that all is good I have to ask . How the heck did you jam your bolt on a rock . Did you drop the BCG on a rock or did a rock some how get in the action ?
Metal god is online now  
Old June 6, 2013, 07:43 PM   #16
American Red Neck
Junior member
 
Join Date: May 8, 2013
Posts: 81
so this is what happened. i was practicing reloading fast and dropping mags in the sand at the river bar (a place i shoot). when i picked up that mag and loaded it there must have been a tiny rock in the mag and it climbed to the top with the shells and the bolt slammed forward on a round trying to load it but the lug next to the extractor slammed on a tiny rock up against the chamber face. it completely smashed the tiny rock into dust and i have been concerned about it ever since. on that same shooting trip i took a bottle of water with a squirt top on it and squirted all the sand and rock particles out of the gun and shot 200 more rounds and all was well. i have shot a total of at least 500 rounds maybe 600 since the jam. you would think if that jam caused a small crack, it would have sheared off by now with that many rounds through it. these bolts are freakin' tough man. i am tempted to put this beautiful piece of art of a bolt (bcm bolt) in though, very tempted. I think i might just to be sure im good to go. i plan on getting a bcm upper in the near future so i can just buy a new bcg with that upper when i do and run the new bolt now. tempted.
American Red Neck is offline  
Old June 6, 2013, 08:59 PM   #17
slim9300
Member
 
Join Date: January 7, 2013
Posts: 72
Found BCM Bolt!!

Quote:
Originally Posted by American Red Neck View Post
dye test results were good no crack. guess i will save the bcm bolt.
Good deal!
slim9300 is offline  
Old June 8, 2013, 08:48 AM   #18
Quentin2
Senior Member
 
Join Date: June 18, 2009
Location: NorthWest USA
Posts: 1,590
You got the BRD bad, Red! Yeah, start a second AR and BCM is a great place to shop.
Quentin2 is offline  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:24 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2013 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.10058 seconds with 9 queries