AR-15 Bolt Difference

[Tactical30]

Is there any difference between the "auto" and "semi" marked AR-15 bolt carriers? I see on all the websites there is no price difference. I had just ordered a "auto" bolt carrier from Bravo Company USA cuz it was the only ones in stock and figured there was no difference. I put the auto carrier next to a semi carrier and do not see any change or difference in anything. Is there? I am using it for 6.5 Grendel AR style build it will be ok to use , wont it? I would think. But you would think there would be a difference if they mark them on their websits as "semi" or "auto". Are they built different or what?!

 

[Turk]

Re: AR-15 Bolt Difference

There is a difference . Towards the rear it is more "cutout" for the semi. You can use the auto one in semi rifle but not viceversa.

 

[CS95]

Re: AR-15 Bolt Difference

I use auto carriers in most of my AR's because of the little bit of extra weight seems to help with the blowback when shooting suppressed.

 

[PistonPete]

Re: AR-15 Bolt Difference

this one is the auto BCG

this one is the semi BCG

the difference is at the rear of the BCG

 

[Autoguns]

Re: AR-15 Bolt Difference

Be careful , Know the laws regarding the installation of FA parts into title 1 firearms .

 

[spiritzerothree]

Re: AR-15 Bolt Difference

an auto bolt carrier is not an NFA part

 

[nhm16]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Autoguns</div><div class="ubbcode-body">Be careful , Know the laws regarding the installation of FA parts into title 1 firearms . </div></div>

It's legal to use an M-16 BCG in your AR-15. Here's a very recent letter from ATF, saying as much:

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

I think the only M-16 parts you really need to worry about are the fire-control parts (trigger group, selector, auto-sear).

 

[Impact]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sp95</div><div class="ubbcode-body">I use auto carriers in most of my AR's because of the little bit of extra weight seems to help with the blowback when shooting suppressed. </div></div>

+1

 

[USAFCATM]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Autoguns</div><div class="ubbcode-body">Be careful , Know the laws regarding the installation of FA parts into title 1 firearms . </div></div>

This is a common mistake, I have spoken to several people & get varied responses. But according to ATF Regs this is legal to use an M16 BCG in an AR15. Some gunsmiths will tell you that modifications are needed but this is incorrect.

 

[Tactical30]

Re: AR-15 Bolt Difference

You would think the heavier bolt carrier would help with the heavier bullets such as the 6.5 Grendel, 6.8 SPC, 7.62 etc.

 

[Tactical30]

Re: AR-15 Bolt Difference

If I had a good scale to weigh the both of them to see how much of an sctual difference in wieght is. Does anybody know?

 

[Tactical30]

Re: AR-15 Bolt Difference

It wont hurt accuracy or anything will it? Would just be a slower bolt return which doesnt really matter if your shooting a Semi-auto anyhow. Am I right?

 

[Tactical30]

Re: AR-15 Bolt Difference

Im going to put it in a 6.5 Grendel Rifle length AR setup. If it is going to screw anything up or hurt anything at all i would like to know. If not Ill run it.

 

[Autoguns]

Re: AR-15 Bolt Difference

Really...Hmmm

 

[Autoguns]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: nhm16</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Autoguns</div><div class="ubbcode-body">Be careful , Know the laws regarding the installation of FA parts into title 1 firearms . </div></div>

It's legal to use an M-16 BCG in your AR-15. Here's a very recent letter from ATF, saying as much:

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

I think the only M-16 parts you really need to worry about are the fire-control parts (trigger group, selector, auto-sear). </div></div>

Excellent info Thanks for posting the link...

The reason I mentioned to check the law is back in the dark days ANY FA parts installed into a T1 gun <span style="font-style: italic"><span style="font-weight: bold">could </span></span>be considered to be intent to convert....I for one really didnt want to spend 25k on lawers over a 100.00 BC

so I just bought a CIII M16

I had a couple AR BC's that had a weight insurted and welded aft of the notch which worked well but I sold em off off once I started useing H buffers...JW

 

[HTR707]

Re: AR-15 Bolt Difference

A few misconceptions here. Perhaps I can help clear them up. Please chime in if you see anything in my post that is erroneous.

1) the ATF letter clearly states that M16 carriers are legal for AR-15 semi-auto's. You can utilize them without worry <span style="font-style: italic">unless</span> you have a trigger in that same rifle that happens to double, and you do nothing about it. If you then lend the gun to someone and he goes to the range to shoot it, you could go to Club-Fed. This is an example of a real-world case, and the guy is serving time. MORAL: just be sure you don't have any other machine gun parts in a Non-NFA registered gun, and that it is not malfunctioning, causing more than one shot to fired with one press of the trigger. Were this to happen in an AR-15 with semi-auto carrier and parts, it would be harder for someone to claim you had intent to assemble a "machine gun."

2) The reasons M16 carriers are somewhat of an advantage are as follows: first, the added weight delays unlocking slightly. This slows the cyclic rate a little, and improves timing, especially in guns which are over-gassed. The delayed unlocking actually allows more gas to escape into a suppressor, where it <span style="font-style: italic">should</span> be, rather than back through the ejection port, where it should not. In turn, this delay of unlocking also reduces ejection-port noise a little when suppressed.

3) Rifles which are already perfectly "gassed," (i.e their gas ports are already sized perfectly so that with the right gas block, they dump the brass at 3-3:30, even with hotter loads), do not need a M16 carrier or a H2 buffer. With more weight to move rearward on ejection, you are delaying the unlocking and slowing timing of a properly timed gun. So, many of the highly tuned precision 6.8 SPC uppers from builders like AR Performance, will actually short stroke when you add these to them. MORAL: when it aint broke don't fix it.

 

[Tactical30]

Re: AR-15 Bolt Difference

So it is actually a benefit to have it if your just shooting semi-auto. ( if it isnt perfectly gassed)

All I want to know is is it going to fuck anything up in my accuracy/shooting/gun performance or should I just go find a regular semi-auto bolt carrier in stock.

 

[infidel762]

Re: AR-15 Bolt Difference

Be careful! You know what they say ignorance is no excuse!

 

[PistonPete]

Re: AR-15 Bolt Difference

just for clarification of the FA carriers, every Colt AR-15 SP-1 had FA carriers, there were many made and that is what caused the feds to put in the M16 FA carriers exemption, some of the very early SP-1s had M16 triggers, most people would never notice the difference, then Colt got the jitters over the "Gun Control Mob" and started making changes to the lowers so that made them "impossible" or at the very least "hard" to convert to "Full Auto"

 

[Hellbender]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Piston Pete</div><div class="ubbcode-body">just for clarification of the FA carriers, every Colt AR-15 SP-1 had FA carriers, there were many made and that is what caused the feds to put in the M16 FA carriers exemption, some of the very early SP-1s had M16 triggers, most people would never notice the difference, then Colt got the jitters over the "Gun Control Mob" and started making changes to the lowers so that made them "impossible" or at the very least "hard" to convert to "Full Auto" </div></div>

Pete, I bought a brand new Colt SP-1 in 1991 (for $240

) and it had the semi bolt carrier with hooked hammer, I also bought a shorty SP-1 a couple years later with the same internals, I don't know exact dates when they changed them, but all SP-1's didn't have FA parts.

At the time, BATF said ANY FA parts were verboten, that is why many people still think the FA carriers are a problem, because back then, they were.

 

[buggsb]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longrange30</div><div class="ubbcode-body">So it is actually a benefit to have it if your just shooting semi-auto. ( if it isnt perfectly gassed)

All I want to know is is it going to fuck anything up in my accuracy/shooting/gun performance or should I just go find a regular semi-auto bolt carrier in stock. </div></div>

Many, if not most of the semi guns now being sold are being delivered with "FA" carriers.

NO, it will not fu@k anything up...use the FA carrier you have.

 

[HTR707]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longrange30</div><div class="ubbcode-body">So it is actually a benefit to have it if your just shooting semi-auto. ( if it isnt perfectly gassed)

All I want to know is is it going to fuck anything up in my accuracy/shooting/gun performance or should I just go find a regular semi-auto bolt carrier in stock. </div></div>


It is not going to fuck anything up. If you find that the gun does indeed short stroke, then you will have to go through the whole process of eliminating variables, like the spring, and buffer weight, and/or the carrier weight being a little too much. HOWEVER, these are about 300% less important to the overall timing of the gun than the gas port size and the gas block positioning.

If the gas port is covered by the gas block slightly, IOW, if it is malpositioned so that the full gas in not conveyed to the gas key, then it will SS no matter what carrier you have in there.

The carrier weight does very little to alter the timing. It is a very slight effect.

I just see a lot of guys put them in rifles, believing that somehow, using 2-3 ozs more in the carrier is going to solve a timing problem...
when it is the gas that is fucked up.

 

[BOLTRIPPER]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hellbender</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Piston Pete</div><div class="ubbcode-body">just for clarification of the FA carriers, every Colt AR-15 SP-1 had FA carriers, there were many made and that is what caused the feds to put in the M16 FA carriers exemption, some of the very early SP-1s had M16 triggers, most people would never notice the difference, then Colt got the jitters over the "Gun Control Mob" and started making changes to the lowers so that made them "impossible" or at the very least "hard" to convert to "Full Auto" </div></div>

Pete, I bought a brand new Colt SP-1 in 1991 (for $240

) and it had the semi bolt carrier with hooked hammer, I also bought a shorty SP-1 a couple years later with the same internals, I don't know exact dates when they changed them, but all SP-1's didn't have FA parts.

At the time, BATF said ANY FA parts were verboten, that is why many people still think the FA carriers are a problem, because back then, they were. </div></div>


PP thinks he knows WTF he is talking about....but alas ....just another jack-ass with a keyboard with ZERO institutional memory,....or more likely a juvenile air-softer .

 

[Guest]

Re: AR-15 Bolt Difference

Theres alot of bullshit in this thread. SH15.com?

 

[Mark Walker]

Re: AR-15 Bolt Difference

Either will work fine for your Grendel, don't sweat it. I am fond of Young SS carriers if for no other reason than they clean up so darn easy.

 

[AlterEgo]

Re: AR-15 Bolt Difference

I run 'auto' carriers in my AR's, but only semi other stuff (trigger parts). I understand that one doesn't want to get into a pissing contest with the ATF about this, BUT all my FAL's have auto everything (I do change to a semi selector though) except obviously the receiver. No one seems to have issues with that...

 

[CS95]

Re: AR-15 Bolt Difference

Your best bet would be to call Sabre or Alexander arms and find out what they prefer as far as gas port size,buffer weight,carrier type. Wish I could help more ,but I honestly have damn near no experience with the 6.5 grendel. I do plan on building one someday though because that is one impressive little round.The fact that it stays supersonic past 1000yds(some say 1200yds)is incredible.

 

[PistonPete]

Re: AR-15 Bolt Difference

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hellbender</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Piston Pete</div><div class="ubbcode-body">just for clarification of the FA carriers, every Colt AR-15 SP-1 had FA carriers, there were many made and that is what caused the feds to put in the M16 FA carriers exemption, some of the very early SP-1s had M16 triggers, most people would never notice the difference, then Colt got the jitters over the "Gun Control Mob" and started making changes to the lowers so that made them "impossible" or at the very least "hard" to convert to "Full Auto" </div></div>

Pete, I bought a brand new Colt SP-1 in 1991 (for $240

) and it had the semi bolt carrier with hooked hammer, I also bought a shorty SP-1 a couple years later with the same internals, I don't know exact dates when they changed them, but all SP-1's didn't have FA parts.

At the time, BATF said ANY FA parts were verboten, that is why many people still think the FA carriers are a problem, because back then, they were. </div></div>


PP thinks he knows WTF he is talking about....but alas ....just another jack-ass with a keyboard with ZERO institutional memory,....or more likely a juvenile air-softer . </div></div>

why the name calling.., ooooh..., i forgot most 12 year olds are into that "jackass" thing, now you can call yourself "Mr. Kool".

the man said he bought his rifle in 1991, but did not state if it was NIB or used, by that time (1991) there was a change, in FACT, many changes were made in the Colts internal lowers, i am speaking of the SP-1s that were made from 1964 thru 1978, my first Colt AR-15 SP-1 was bought NIB in 1968ad.., to the best of my recollection there were no more SP-1s made after the AR-15A1 was introduced.