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under9
08-13-08, 08:56
I have a LMT lower and looking at LMT bolts. I was wondering which one to get the Semi auto or the Full auto? What are the pros and cons of having a Full auto bolt and Do I have to get a heavier buffer? I have a carbine buffer in it now.
Thanks
Josh

OldNavyGuy
08-13-08, 09:15
i presume you are referring to the FA CARRIER ??

as for the FA carrier, some of my AR-15s come with the FA carrier, all my active AR-15s have the full circle carrier, some collectibles have the "shaved" carrier.

i prefer the heavier carrier for the inertia factor, some folks say there is no difference, yet i have experienced some minor difficulties with the shaved carrier. (FTF, fail to feed)

markm
08-13-08, 09:24
To me the more important part is the shrouded firing pin area. It just so happens that all FA carriers have the shrouded firing pin so I go with FA.

I've seen some Colt Semi carriers with the shroud though. The weight isn't a significant issue to me. The buffer selection should be where that is addressed in my opinion.

under9
08-13-08, 09:38
Sorry for that. I do mean FA BCG. If I get a FA BCG would I need to get a H buffer?

C4IGrant
08-13-08, 09:40
Sorry for that. I do mean FA BCG. If I get a FA BCG would I need to get a H buffer?


If you have a carbine gas system, I would get one..


C4

under9
08-13-08, 09:42
It is LMT 16in barrel. What is the difference between h buffer and a h2 buffer?

wichaka
08-13-08, 10:03
Yep, I always look for the shrouded FP first.........

markm
08-13-08, 10:35
It is LMT 16in barrel. What is the difference between h buffer and a h2 buffer?

.9 oz. H is 3.8oz, and H2 is 4.7oz according to the list I have in front of me.

S.A.W. recommends and H buffer for 16 inch carbeans, H2 for 14.5 inch, and H3 for the short stuff..... take it or leave it. ;)

ARin
08-13-08, 11:45
more weight on the FA carrier. increased dwell, slows cyclic rate, lower "perceived" recoil, but some folks dont like the feeling of the extra reciprocating mass. makes the carbine less "snappy" and more "pushy".

regardless, an FA carrier and H or H2 buffer is the "correct" way to run a carbine gas system.

under9
08-13-08, 12:18
Thanks for the help! I am going to try the FA BCG with H buffer and how it feels if I dont like I will just buy a Semi BCG and use the FA BCG as a spare.:D

markm
08-13-08, 12:43
Thanks for the help! I am going to try the FA BCG with H buffer and how it feels if I dont like I will just buy a Semi BCG and use the FA BCG as a spare.:D

If you can feel the difference between a semi and FA carrier, you should have scientists study your extraordinary senses!

mike240
08-13-08, 16:33
I would be interested to hear if anyone has a letter from ATF you can put M16 carrier in their guns that came with semi carriers. According to my understanding and from SAW, the letter to Colt that was floating around is a letter that authorized Colt to it and those technical letters are manufacturer specific. So it only allowed Colt to do it in newly manufactured weapons.

Even though we all know that the full auto carrier will not make a semi gun fire auto, I would trust my sources on this though the odds of getting jammed for doing are slim to none. Most ATF field agents wouldn't know the difference anyways in my experience.

Using a heavier buffer would be the safest bet unless someone know otherwise.

C4IGrant
08-13-08, 16:38
I would be interested to hear if anyone has a letter from ATF you can put M16 carrier in their guns that came with semi carriers. According to my understanding and from SAW, the letter to Colt that was floating around is a letter that authorized Colt to it and those technical letters are manufacturer specific. So it only allowed Colt to do it in newly manufactured weapons.

Even though we all know that the full auto carrier will not make a semi gun fire auto, I would trust my sources on this though the odds of getting jammed for doing are slim to none. Most ATF field agents wouldn't know the difference anyways in my experience.

Using a heavier buffer would be the safest bet unless someone know otherwise.

http://www.gandrtactical.com/images/archive/M16%20BCG%20ATF%20Letter.jpg



C4

jlficken
08-13-08, 17:05
That last sentence seems to be the key. It doesn't seem to matter one way or another as long as the gun is not capable of firing more than ONE round with ONE pull of the trigger. I would be more concerned about a malfunction with my FCG making it go full-auto than having an M16 bolt carrier in it. Just remember the gun was designed to use an M16 bolt carrier from the beginning.

b_saan
08-13-08, 17:23
I would be interested to hear if anyone has a letter from ATF you can put M16 carrier in their guns that came with semi carriers. According to my understanding and from SAW, the letter to Colt that was floating around is a letter that authorized Colt to it and those technical letters are manufacturer specific. So it only allowed Colt to do it in newly manufactured weapons.

Even though we all know that the full auto carrier will not make a semi gun fire auto, I would trust my sources on this though the odds of getting jammed for doing are slim to none. Most ATF field agents wouldn't know the difference anyways in my experience.

Using a heavier buffer would be the safest bet unless someone know otherwise.

Please, let's not start in on that old chestnut again...

wichaka
08-13-08, 19:31
ATF finally gave in and decided the BC was not part of the auto group in person, but they won't tell you that in written form.

Robb Jensen
08-13-08, 20:19
Lets break this down to American english terms:

If your rifle shoots more than one round per trigger press. It's ruled by BATF to be a machinegun REGARDLESS of whether or not it has an AUTO or a SEMI carrier.........OR if your side-by-side or over-and-under shotgun fires both barrels at the same time, IT TOO is a machinegun.....

Or to redneck terms:

If ur gun shoots more then 1 'bullet' with 1 trigger pull, it's a dern macheene
gun....full-audo carryer or not.

McQ68
08-13-08, 21:00
I didn't know you could speak redneck, you must be from around here.:cool:

Blankwaffe
08-14-08, 00:06
Hay wach tha redneck jokes...sumofus mit giter fellins hert.

McQ68
08-14-08, 00:33
The scary part is, that I understand you, you any kin to Jeff Foxworthy or Tater?;)

wichaka
08-14-08, 02:05
Got sum far wood fer sale.

mike240
08-14-08, 06:20
Lets break this down to American english terms:

If your rifle shoots more than one round per trigger press. It's ruled by BATF to be a machinegun REGARDLESS of whether or not it has an AUTO or a SEMI carrier.........OR if your side-by-side or over-and-under shotgun fires both barrels at the same time, IT TOO is a machinegun.....

Or to redneck terms:

If ur gun shoots more then 1 'bullet' with 1 trigger pull, it's a dern macheene
gun....full-audo carryer or not.

Yea, I got it and you get it, but we are talking about the ATF. I ve been present when they come and do inspections at shops and send the "wine cops" of the ATF. They can cause a guy a lot of trouble for years despite being found innocent later. I just think people should be aware of the possible chances taken in these matters. I ve had to work details and task forces with these guys.....

Dorsai
08-15-08, 22:56
Just to add something different here, I tried an FA bolt carrier in my 16" midlength. It functioned great with a standard carrier but wouldn't run with the FA carrier. Standard buffer. Go figure.

28_days
08-15-08, 23:14
Just to add something different here, I tried an FA bolt carrier in my 16" midlength. It functioned great with a standard carrier but wouldn't run with the FA carrier. Standard buffer. Go figure.

With a carbine buffer? Really? Many people use a FA/H buffer combo in their 16" mid-lengths with no problems. What manufacturer? Or at least what upper?

under9
08-16-08, 00:16
It is LMT 16in barrel. I want to get a FA BCG and was wondering if I need to get a H buffer with it.

acerman
08-16-08, 00:48
Would someone mind explaining what an H buffer is and does? what is a carrier also? To a rookie like myself.

ARin
08-16-08, 01:25
Just to add something different here, I tried an FA bolt carrier in my 16" midlength. It functioned great with a standard carrier but wouldn't run with the FA carrier. Standard buffer. Go figure.

if it is a good quality bbl, then the gas port will be correct size, rather than the "commercial" large size that companies like RRA, DPMS, BM et al use.

midlength gas pulse from a small gas port might not have enough "umph" to push the extra weight of a FA carrier, regardless of how light the buffer weight.

Ill copy and paste what i have posted elsewhere, in reply to the question of heavier buffers.


Not all carbines will run them.

depends on a lot of factors. BCG drag, buffer spring rate and age, barrel quality/gas seal, gas port size, FSB fit and gas seal, etc etc...

any one of those, or a combination of those things may preclude the use of a heavy buffer.

TO determine the buffer your carbine SHOULD be running, do the following.

dont clean your carbine for at least 500 rds.
take one of each weight buffer to the range, carbine, H, H1, H2, H3, 9mm
Load single rounds of WOLF in mags, and test with at LEAST 20 rounds for each buffer. just one round per mag, testing to see that the carbine locks back after that shot every time.

Whatever the HEAVIEST buffer is, that will STILL Reliably lock back on an empty mag, in a dirty carbine, shooting underpowered ammo........

is the buffer you want.

a good majority of quality carbines will stop at an H2 buffer. "commercial" type AR's may need a heavier buffer due to large (non spec) gas port size.

and i will add this.

do yourself even one better, and fully load several mags. take one shot, then top off. do that over and over to also add in the factor of carrier drag on the stiff top round of a fully loaded mag.

wichaka
08-16-08, 07:07
Would someone mind explaining what an H buffer is and does? what is a carrier also? To a rookie like myself.

In the buffer is either steel or tunsten inserts. Tungsten being heavier than steel, one can get more weight in the same amount of room.

There is H, 2H, and 3H buffers. H has one peice of tungsten and 2 steel, 2H has two tungsten and 1 steel, and so on..........

This is based on a carbine buffer, not a rifle..............they are much different.

C4IGrant
08-16-08, 08:26
It is LMT 16in barrel. I want to get a FA BCG and was wondering if I need to get a H buffer with it.

I would put on in it.


C4

Iraqgunz
08-16-08, 09:40
Let's think about this rationally for just a minute. If having a full-auto bolt carrier in your rifle or carbine was illegal, then the BATFE would have gone to every manufacturer that puts them in their rifles and carbines and shut them down. They would have been charged with ridiculous stuff like "conspiracy" possession of a machine gun, ad nauseum.

If I am not mistaken my Noveske came with one so I guess I will turn myself in for being a criminal, then I will cut a deal and turn John in also.


Yea, I got it and you get it, but we are talking about the ATF. I ve been present when they come and do inspections at shops and send the "wine cops" of the ATF. They can cause a guy a lot of trouble for years despite being found innocent later. I just think people should be aware of the possible chances taken in these matters. I ve had to work details and task forces with these guys.....

shootmovecomm
08-16-08, 10:34
Let's think about this rationally for just a minute. If having a full-auto bolt carrier in your rifle or carbine was illegal, then the BATFE would have gone to every manufacturer that puts them in their rifles and carbines and shut them down. They would have been charged with ridiculous stuff like "conspiracy" possession of a machine gun, ad nauseum.

If I am not mistaken my Noveske came with one so I guess I will turn myself in for being a criminal, then I will cut a deal and turn John in also.

Thats hilarious Iraqgunz and I would have to agree with you. I deal with the ATF daily and it is not the bolt carrier group that brings the weapon into question, it is the guts in the lower. They could care less about a full auto bolt carrier going into a semi auto matic upper receiver.

wichaka
08-16-08, 11:34
They could care less about a full auto bolt carrier going into a semi auto matic upper receiver.


That's for sure, as many Colts come with them out of the factory.

aalmcc4
08-16-08, 13:29
Can someone please post a picture comparison of the FA BC, the semi BC, the shrouded carrier etc?

28_days
08-16-08, 14:52
Can someone please post a picture comparison of the FA BC, the semi BC, the shrouded carrier etc?

I can't find my picture, but go here: http://www.bravocompanyusa.com/AR-15-Bolt-Carrier-Group-Parts-s/34.htm

Scroll down to the CMT BCG's (about half way down). See how the FA carrier looks different on the right-hand side?

A shrouded firing pin is just that, shrouded. Virtually all FA carriers have shrouded firing pins. Does it make a big difference? Questionable, but people seem to prefer it.

The biggest difference, as already mentioned, is weight. The FA slows the cycling a bit, causing less internal wear. In combination with a heavier buffer (an H, even an H2 in a 14.5) makes for more reliable cycling.

RogerinTPA
08-16-08, 17:19
Checking out the knowledge based threads might help here: https://www.m4carbine.net/showthread.php?t=14534


Can someone please post a picture comparison of the FA BC, the semi BC, the shrouded carrier etc?

heh2k
08-17-08, 18:20
If your sear is worn and it goes burst or full auto, the heavier "full auto" carrier might be used against you. Remember, the prosecution will use everything they can. They might argue you knew it was malfunctioning, liked it that way, and put in a "full auto" carrier to make it work better. (If it was original equipment you have a good defense, tho.)

markm
08-17-08, 18:35
If your sear is worn and it goes burst or full auto, the heavier "full auto" carrier might be used against you. Remember, the prosecution will use everything they can. They might argue you knew it was malfunctioning, liked it that way, and put in a "full auto" carrier to make it work better. (If it was original equipment you have a good defense, tho.)

The weight of the carrier would have nothing to do with this scenario.... neither would the characteristic that separates a 16 carrier from an emasculated carrier.

If you have a faulty disconnector (not the sear... there is no sear in an AR), then the shroud on the carrier is what would allow the hammer to slam fire and create a burst of some sort.

Iraqgunz
08-18-08, 04:20
I am fairly certain that the first thing the prosecution will focus on is the fact that you have a "sear" in a semi-auto weapon. Otherwise I think demigod spelled it out. And since some manufacturers put full auto bolt carriers in their guns when they sell them, that would make it original equipment. Wouldn't it.? :confused:


If your sear is worn and it goes burst or full auto, the heavier "full auto" carrier might be used against you. Remember, the prosecution will use everything they can. They might argue you knew it was malfunctioning, liked it that way, and put in a "full auto" carrier to make it work better. (If it was original equipment you have a good defense, tho.)

MassMark
08-18-08, 08:20
All I know is that BCM makes one beautiful bolt carrier group and I can't wait until it's dropping into my Anvil Arms upper, (any day now!). The decision to buy the BCM was easy thanks to information right here on M4C. I think running a carbine length system with the M-16 carrier is cheap insurance. One my be just dandy with an AR carrier, but the M-16 BCM seems to just make sense...

t4man
08-19-08, 10:00
Cool, Ive been wanting to ask this also.