PDA

View Full Version : Bolt Carrier forge markings.



-=Jeff=-
06-26-07, 23:20
I just joined the forum and have really enjoyed reading all the technical info. I have found some great info by "gotm4" reguarding forge markings on uppers on a sticky. (Thanks gotm4!) Does anyone know who manufactures a Bolt Carrier with a "J" forge marking?

Thanks,
Jeff

Robb Jensen
06-27-07, 07:31
I've never seen one with that marking. Is the bore of it chrome lined? Got any pics?

-=Jeff=-
06-27-07, 10:24
Thank you for looking at these. The rifle it is from is a frankenrifle, a friend built it using a Colt 16" 1/12 barrel. The lower is a Bushmaster with the L prefix on the serial number. The upper is a Bushmaster A1 with a "K" forge marking (Kaiser Aluminum IIRC) and has the purple haze look to the finish. Sorry about the crappy pic. Time for a new camera.

Thanks,
Jeff

http://i196.photobucket.com/albums/aa55/atcsjeff/P1010029.jpg

Ekie
07-27-07, 21:20
J carriers are a USGI replacement part that are are commonly found on rebuilt USGI M16A1 rifles. They were made by Smith Enterprise for JC manufacturing in the mid 1980's. Good stuff.

glklvr
07-27-07, 23:05
Is "A" for Armalite or someone else?

MASP7
07-27-07, 23:47
Is "A" for Armalite or someone else?

Advanced Ordnance Corp (CAGE 077H9)
USGI replacement carrier.

glklvr
07-28-07, 08:26
Ahhh. Thanks!

AR15barrels
07-28-07, 22:38
The stampings on the sides of carriers are "manufacturer's markings", not forge markings.

There is no need for forgings to be used to make a carrier when simple bar stock (billets) would suffice.

C4IGrant
07-29-07, 15:49
Advanced Ordnance Corp (CAGE 077H9)
USGI replacement carrier.


AO holds the current DoD contract for small replacement parts and is where we get our BCG's and upper receivers. Fantastic quality at a fair price.



C4

glklvr
07-29-07, 22:28
AO holds the current DoD contract for small replacement parts and is where we get our BCG's and upper receivers. Fantastic quality at a fair price.



C4

Well now I feel better about running one in my BM upper.

bradb55
07-29-07, 22:40
I was looking over my Bolt Carrier and notice it didn't have any markings on it. Does it mean its a P.O.S. bolt carrier or is it common not to have factory markings?

AR15barrels
07-30-07, 01:32
I was looking over my Bolt Carrier and notice it didn't have any markings on it. Does it mean its a P.O.S. bolt carrier or is it common not to have factory markings?

The presence or lack of markings is not enough to decide if a carrier is good or not.
For example, LMT carriers don't have markings, but DPMS do.
Which would you rather have?
If the carrier is well machined and the bolt moves smoothly in the chrome lined bolt recess, then it's most likely an acceptable part.
It should have a chrome lined gas key with good staking on the gas key so that the screws can't come loose with use.
Ideally it would have a shrouded firing pin such as the "AR15 enhanced" and "M16" carriers below.

http://ar15barrels.com/tech/ar15carriers.jpg

-=Jeff=-
07-30-07, 10:27
Ekie, thanks you for ID'ing this BCG. I can now go to sleep at night without the last thought in my head being, "Who makes that damn J"

Randall and Grant, thank ya'll for for the added information and education. I kept seeing "forge markings" so I thought it applied to BCGs as well. Thats why I think this is the best AR site, if you are not careful, you just might learn something! :D

bradb55
07-30-07, 21:10
The presence or lack of markings is not enough to decide if a carrier is good or not.
For example, LMT carriers don't have markings, but DPMS do.
Which would you rather have?
If the carrier is well machined and the bolt moves smoothly in the chrome lined bolt recess, then it's most likely an acceptable part.
It should have a chrome lined gas key with good staking on the gas key so that the screws can't come loose with use.
Ideally it would have a shrouded firing pin such as the "AR15 enhanced" and "M16" carriers below.

http://ar15barrels.com/tech/ar15carriers.jpg
Thanks.

Razorhunter
07-30-07, 22:07
How does everyone here feel about the LMT "Enhanced Carriers"?
I'm not sure if that "Enhanced" carrier pictured by Randall up above is an LMT "Enhanced" carrier or not? Doesn't look like it, as I thought the LMT Enhanced carriers had that special coating (shiny) on them.
Regardless, I have had one respectable guy tell me he does not like the LMT Enhanced design, as it apparently has an extra gas vent/port hole in it?
Not sure of the scientific reasoning behind the Enhanced LMT carriers, but I'd like to know what you guys think about them.

AR15barrels
07-31-07, 02:18
How does everyone here feel about the LMT "Enhanced Carriers"?
I'm not sure if that "Enhanced" carrier pictured by Randall up above is an LMT "Enhanced" carrier or not? Doesn't look like it, as I thought the LMT Enhanced carriers had that special coating (shiny) on them.
Regardless, I have had one respectable guy tell me he does not like the LMT Enhanced design, as it apparently has an extra gas vent/port hole in it?
Not sure of the scientific reasoning behind the Enhanced LMT carriers, but I'd like to know what you guys think about them.

The picture above is still a regular style carrier, not an LMT "enhanced" carrier.
The LMT's should really be called "advanded" carriers because they have several distinct changes, all aimed at correcting over-gassed carbine barrels.

First, they have extended the cam pin slot which delays the unlocking of the bolt.
This required the front end of the carrier to extend slightly and you can see that this extension actually fits slightly into the chamfer on the barrel extension.
Second, they added the extra exhaust port to let the pressure bleed off quicker inside the carrier when the gas rings pass the exhast port during unlocking.
Then there is an extra exhaust port to relieve whatever gas gets past the tail of the bolt.
Then there is the reliefs on the bearing points where the carrier contacts the receiver.

The LMT enhanced carriers are good in 14.5" and 16" carbine barrels.
You don't NEED one in a mid-length barrel because mid-length barrels are not as over-gassed and run at reduced pressures already.
You don't WANT one in a 10.5" or 11.5" barrel as they will actually cause problems due to the lack of gas system dwell time on short barrels.

LMT enhanced CARRIERS don't have a different finish.
LMT enhanced BOLTS are electroless nickel plated.

dsmithla
08-07-07, 11:34
Would the Enhanced Carrier provide ANY benefit in a mid length (since the pressure is still somewhat higher than a rifle length system?

Tx.

Dave



The picture above is still a regular style carrier, not an LMT "enhanced" carrier.
The LMT's should really be called "advanded" carriers because they have several distinct changes, all aimed at correcting over-gassed carbine barrels.

First, they have extended the cam pin slot which delays the unlocking of the bolt.
This required the front end of the carrier to extend slightly and you can see that this extension actually fits slightly into the chamfer on the barrel extension.
Second, they added the extra exhaust port to let the pressure bleed off quicker inside the carrier when the gas rings pass the exhast port during unlocking.
Then there is an extra exhaust port to relieve whatever gas gets past the tail of the bolt.
Then there is the reliefs on the bearing points where the carrier contacts the receiver.

The LMT enhanced carriers are good in 14.5" and 16" carbine barrels.
You don't NEED one in a mid-length barrel because mid-length barrels are not as over-gassed and run at reduced pressures already.
You don't WANT one in a 10.5" or 11.5" barrel as they will actually cause problems due to the lack of gas system dwell time on short barrels.

LMT enhanced CARRIERS don't have a different finish.
LMT enhanced BOLTS are electroless nickel plated.

AR15barrels
08-07-07, 12:52
Would the Enhanced Carrier provide ANY benefit in a mid length (since the pressure is still somewhat higher than a rifle length system?

No.
In fact, Robb has even seen it to cause short stroking in one case.

Mid-length barrels don't have the issue of pre-mature extraction.
THAT is what most of the carbine gas system "patches" are trying to solve for.

Lexington
11-20-07, 17:06
Here is another photo of the J.C. Manufacturing M16 bolt carrier:

http://i209.photobucket.com/albums/bb118/Lexington449/137-3742_IMG.jpg
http://i209.photobucket.com/albums/bb118/Lexington449/137-3745_IMG.jpg

Jim D
11-21-07, 02:43
Sorry for the Hijack....BUT...

Is there anything really desirable about the SP1 carrier? Aside from collecting, or to make a rifle "authentic"?

I have a friend who had a custom rig built w/ one of these carriers in there..and he gets doubles with his 2# trigger occasionally....I'm thinking a shrouded carrier would help eliminate this problem...yes?

So, is there any reason why someone would want a SP1 carrier in their gun?

Thanks

Robb Jensen
11-21-07, 05:54
Doubles typically mean the the hammer and/or trigger need replacing. I replace these as a set along with a new disconnector and all new springs.

recce556
04-30-08, 22:26
So did Advanced Ordnance ever make Bolts or were they just carriers?

C4IGrant
05-01-08, 09:24
So did Advanced Ordnance ever make Bolts or were they just carriers?


They make both.


C4

black6
12-27-11, 21:02
Any idea what the market value of a "C" marked stripped M16 bolt carrier is?

lamarbrog
12-27-11, 21:38
Any idea what the market value of a "C" marked stripped M16 bolt carrier is?

A brand new stripped carrier is only about $50.

Since that one is used... I'd not give more than $30 or so for it.

Tweak
12-27-11, 23:15
his 2# trigger

standard FCG and 2#?

markm
12-28-11, 09:11
standard FCG and 2#?

This thread was started on the Mayflower. Most of the original posters are pushing up daisies at this point. :rolleyes:

Tweak
12-28-11, 19:48
I got time ;)