Can I Modify My Bolt Carrier or Please Keep Me From Blowing Myself Up.

larphred · April 17, 2002, 22:57

I posted yesterday about a Century ejector block problem but got no replies. I needs help. On Century's new L1A1 receiver the portion of the ejector block that appears to be a bolt carrier forward stop keeps the bolt carrier from going into full battery. To me the obvious solution is to machine about .060" off of the lower rear tang of the bolt carrier to allow said carrier to go further forward but am unsure if it will alter other geometries. If you can understand what I am saying I would appreciate input.

Dave1 · April 18, 2002, 00:26

No, send it back. Sounds like the ejector block is installed incorrect. It should be flush with the bottom of the reciever. I wouldn't remove anything from the carrier. Even Century should stand behind that screw up

Dave

aleph_beth · April 18, 2002, 12:01

i dont think there should be a bolt carrier forward stop. this is not the first report of problems in this area. is your magazine well unusually tight? high, low,or canted to one side ejector blocks are showing up. some say it is the pin holes drilled incorrectly.

larphred · April 18, 2002, 22:43

aleph--the ejector block seems to be in the right place and straight. I compared it to a bare Imbel and a bare WAC receiver and they all have the same protrusion. Carefully viewing through the locking shoulder hole with a flashlight shows the tang on the rear of the bolt carrier contacting the protrusion--on all three receivers. The problem with the Century receiver is that the contact is made before the carrier goes into full battery.

Derby FALs · April 18, 2002, 23:57

Some IMBEL receivers have a burr that hits the top front of the bolt that will keep it from going into battery. There is no excuse for that being shipped like that if it is the problem.

ce · April 19, 2002, 08:13

Dude, I'm not sure the carrier goes into battery. The bolt does, but the carrier just rides the rails. I forgot to check my Century inch, but I also noticed that one carrier was short of flush on closing, so I swapped it for one that closed better.
Does the piston protrude into the breech?

larphred · April 19, 2002, 13:14

ce: I'm only using "battery" figuratively. What I meant was that the carrier lacks .060" from closing or there is a .060" gap when it is in the forward position. I looked at all my other FALs and there is only a very slight gap. I've tried several carriers on the 2 Century receivers I have and also the same carriers in other bare receivers. The Century receivers are the only ones with the problem. If the bolt cams over the LS and I get the proper headspace, is it safe to shoot with that .060" gap or not?
Thanks

ce · April 19, 2002, 13:40

I think so, Phred, I've not yet completed my Centurific enough for testing, the guages indicate proper headspace, etc.
The receiver was quirky enough to piss me off in several regards, the non-closing carrier was just one more thing.
I want to check a Cen-gun built by them to see if this condition is prevalent on all receivers or every now (yours) and then(mine)
For another 50 bucks, I coulda had an Imbel, but at least it's inch cut and all.
Shoot it.

larphred · April 19, 2002, 15:01

ce: I just spoke with Andy at Century. There are a couple of great guys there--John Price and Andy. I am sending him photos of the dilemma. His initial suggestion was along the same lines as mine, i.e., mill off .060" of the tang at the rear of the bolt, but he wants the tech folks to look at the photos. I'll keep you posted when I hear from them.
Thanks for the input.

aleph_beth · April 19, 2002, 15:24

is this a hesse made reciever? i have a hesse that functions well and the carrier exhibits the same gap near the face. i see the gap you mentioned. at first i thought it was the gas piston holding it open a bit, but with the piston out, the carrier still closes solidly leaving the gap. if the carrier can force the bolt into lockup, that is if the camming surfaces engage at the rear of the bolt. i would think the bolt is preventing the last bit of forward movement . if it is the ejector block stopping the carrier, the gap should still be there if you assemble without the bolt. in any case i have fired this setup 1000's of rounds and the only wear i am finding where it is apparent that metal hits metal is 1.the carrier pushing the bolt forward (inside rear face of carrier) 2. where the carrier cams the bolt into battery (top), and 3. where the carrier cams the bolt up out of battery(sides). the most wear being apparent on the side cams of the carrier. i have carrier contact with the reciever face( but not much) on the side opposite the ejection port.

larphred · April 20, 2002, 18:00

aleph--no it's not a Hesse. It's one of Century's new receivers. I know what's stopping the forward progress of the carrier--it's the rear trailing tab on the bolt carrier engaging the upper protrusion of the ejector housing (the protrusion opposite the ejector proper). I'm really close to machining the tab off of the bolt carrier because nobody on the files seems to know anything about it. I've e-mailed photos to Century asking their opinion, so as soon as I receive a reply, I'll let you know. It'd be a simple fix to the problem if it doesn't screw up some other clearances. I'll keep you posted.

April 17, 2002, 22:57	#1
larphred Registered FALaholic #: 1555 Join Date: Nov 2000 Location: Sandy, Ut. Posts: 3,098	Can I Modify My Bolt Carrier or Please Keep Me From Blowing Myself Up. I posted yesterday about a Century ejector block problem but got no replies. I needs help. On Century's new L1A1 receiver the portion of the ejector block that appears to be a bolt carrier forward stop keeps the bolt carrier from going into full battery. To me the obvious solution is to machine about .060" off of the lower rear tang of the bolt carrier to allow said carrier to go further forward but am unsure if it will alter other geometries. If you can understand what I am saying I would appreciate input. __________________ Michael O'Sullivan was my great friend. But I don't ever remember telling him that. The words that are spoken at a funeral are spoken too late for the man who is dead. What a wonderful thing it would be to visit your own funeral. To sit at the front and hear what was said, maybe say a few things yourself. Michael and I grew old together. But at times, when we laughed, we grew young. If he was here now, if he could hear what I say, I'd congratulate him on being a great man, and thank him for being a friend. -------------------------------------------------------------------------------- --the forty-four spoke and it sent lead and smoke, and seventeen inches of flame. ----Marty Robbins

April 18, 2002, 00:26	#2
Dave1 Registered FALaholic #: 156 Join Date: Jul 2000 Location: First left past nowhere in MN Posts: 1,184	No, send it back. Sounds like the ejector block is installed incorrect. It should be flush with the bottom of the reciever. I wouldn't remove anything from the carrier. Even Century should stand behind that screw up Dave __________________ Barack Obama, the best gun salesman since Bill Clinton NRA Life Member, SAF Defender Club, Life Member

April 18, 2002, 12:01	#3
aleph_beth Registered FALaholic #: 4660 Join Date: Nov 2001 Location: pa.usa Posts: 85	i dont think there should be a bolt carrier forward stop. this is not the first report of problems in this area. is your magazine well unusually tight? high, low,or canted to one side ejector blocks are showing up. some say it is the pin holes drilled incorrectly. __________________ bb

April 18, 2002, 22:43	#4
larphred Registered FALaholic #: 1555 Join Date: Nov 2000 Location: Sandy, Ut. Posts: 3,098	aleph--the ejector block seems to be in the right place and straight. I compared it to a bare Imbel and a bare WAC receiver and they all have the same protrusion. Carefully viewing through the locking shoulder hole with a flashlight shows the tang on the rear of the bolt carrier contacting the protrusion--on all three receivers. The problem with the Century receiver is that the contact is made before the carrier goes into full battery. __________________ Michael O'Sullivan was my great friend. But I don't ever remember telling him that. The words that are spoken at a funeral are spoken too late for the man who is dead. What a wonderful thing it would be to visit your own funeral. To sit at the front and hear what was said, maybe say a few things yourself. Michael and I grew old together. But at times, when we laughed, we grew young. If he was here now, if he could hear what I say, I'd congratulate him on being a great man, and thank him for being a friend. -------------------------------------------------------------------------------- --the forty-four spoke and it sent lead and smoke, and seventeen inches of flame. ----Marty Robbins

April 18, 2002, 23:57	#5
Derby FALs Supreme Leader FALaholic #: 2361 Join Date: Jan 2001 Location: Louisville, Kentucky Posts: 2,610	Some IMBEL receivers have a burr that hits the top front of the bolt that will keep it from going into battery. There is no excuse for that being shipped like that if it is the problem. __________________ “Rightful liberty is unobstructed action according to our will within limits drawn around us by the equal rights of others. I do not add "within the limits of the law" because law is often but the tyrant's will, and always so when it violates the rights of the individual.” - Thomas Jefferson Salami, salami, baloney... :bow: http://www.derbyfals.com/home.htm

April 19, 2002, 08:13	#6
ce Registered FALaholic #: 373 Join Date: Jul 2000 Location: New Mexico Posts: 5,903	Dude, I'm not sure the carrier goes into battery. The bolt does, but the carrier just rides the rails. I forgot to check my Century inch, but I also noticed that one carrier was short of flush on closing, so I swapped it for one that closed better. Does the piston protrude into the breech?

April 19, 2002, 13:14	#7
larphred Registered FALaholic #: 1555 Join Date: Nov 2000 Location: Sandy, Ut. Posts: 3,098	ce: I'm only using "battery" figuratively. What I meant was that the carrier lacks .060" from closing or there is a .060" gap when it is in the forward position. I looked at all my other FALs and there is only a very slight gap. I've tried several carriers on the 2 Century receivers I have and also the same carriers in other bare receivers. The Century receivers are the only ones with the problem. If the bolt cams over the LS and I get the proper headspace, is it safe to shoot with that .060" gap or not? Thanks __________________ Michael O'Sullivan was my great friend. But I don't ever remember telling him that. The words that are spoken at a funeral are spoken too late for the man who is dead. What a wonderful thing it would be to visit your own funeral. To sit at the front and hear what was said, maybe say a few things yourself. Michael and I grew old together. But at times, when we laughed, we grew young. If he was here now, if he could hear what I say, I'd congratulate him on being a great man, and thank him for being a friend. -------------------------------------------------------------------------------- --the forty-four spoke and it sent lead and smoke, and seventeen inches of flame. ----Marty Robbins

April 19, 2002, 13:40	#8
ce Registered FALaholic #: 373 Join Date: Jul 2000 Location: New Mexico Posts: 5,903	I think so, Phred, I've not yet completed my Centurific enough for testing, the guages indicate proper headspace, etc. The receiver was quirky enough to piss me off in several regards, the non-closing carrier was just one more thing. I want to check a Cen-gun built by them to see if this condition is prevalent on all receivers or every now (yours) and then(mine) For another 50 bucks, I coulda had an Imbel, but at least it's inch cut and all. Shoot it.

April 19, 2002, 15:01	#9
larphred Registered FALaholic #: 1555 Join Date: Nov 2000 Location: Sandy, Ut. Posts: 3,098	ce: I just spoke with Andy at Century. There are a couple of great guys there--John Price and Andy. I am sending him photos of the dilemma. His initial suggestion was along the same lines as mine, i.e., mill off .060" of the tang at the rear of the bolt, but he wants the tech folks to look at the photos. I'll keep you posted when I hear from them. Thanks for the input. __________________ Michael O'Sullivan was my great friend. But I don't ever remember telling him that. The words that are spoken at a funeral are spoken too late for the man who is dead. What a wonderful thing it would be to visit your own funeral. To sit at the front and hear what was said, maybe say a few things yourself. Michael and I grew old together. But at times, when we laughed, we grew young. If he was here now, if he could hear what I say, I'd congratulate him on being a great man, and thank him for being a friend. -------------------------------------------------------------------------------- --the forty-four spoke and it sent lead and smoke, and seventeen inches of flame. ----Marty Robbins

April 19, 2002, 15:24	#10
aleph_beth Registered FALaholic #: 4660 Join Date: Nov 2001 Location: pa.usa Posts: 85	is this a hesse made reciever? i have a hesse that functions well and the carrier exhibits the same gap near the face. i see the gap you mentioned. at first i thought it was the gas piston holding it open a bit, but with the piston out, the carrier still closes solidly leaving the gap. if the carrier can force the bolt into lockup, that is if the camming surfaces engage at the rear of the bolt. i would think the bolt is preventing the last bit of forward movement . if it is the ejector block stopping the carrier, the gap should still be there if you assemble without the bolt. in any case i have fired this setup 1000's of rounds and the only wear i am finding where it is apparent that metal hits metal is 1.the carrier pushing the bolt forward (inside rear face of carrier) 2. where the carrier cams the bolt into battery (top), and 3. where the carrier cams the bolt up out of battery(sides). the most wear being apparent on the side cams of the carrier. i have carrier contact with the reciever face( but not much) on the side opposite the ejection port. __________________ bb

April 20, 2002, 18:00	#11
larphred Registered FALaholic #: 1555 Join Date: Nov 2000 Location: Sandy, Ut. Posts: 3,098	aleph--no it's not a Hesse. It's one of Century's new receivers. I know what's stopping the forward progress of the carrier--it's the rear trailing tab on the bolt carrier engaging the upper protrusion of the ejector housing (the protrusion opposite the ejector proper). I'm really close to machining the tab off of the bolt carrier because nobody on the files seems to know anything about it. I've e-mailed photos to Century asking their opinion, so as soon as I receive a reply, I'll let you know. It'd be a simple fix to the problem if it doesn't screw up some other clearances. I'll keep you posted. __________________ Michael O'Sullivan was my great friend. But I don't ever remember telling him that. The words that are spoken at a funeral are spoken too late for the man who is dead. What a wonderful thing it would be to visit your own funeral. To sit at the front and hear what was said, maybe say a few things yourself. Michael and I grew old together. But at times, when we laughed, we grew young. If he was here now, if he could hear what I say, I'd congratulate him on being a great man, and thank him for being a friend. -------------------------------------------------------------------------------- --the forty-four spoke and it sent lead and smoke, and seventeen inches of flame. ----Marty Robbins

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