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Posted: 9/29/2004 5:02:54 AM EST
I've seen 9mm buffers advertised as accessories, but are they required? AFIK, they are heavier than a stock CAR buffer...is that because the 9 is a blowback? Are there benefits to using one of these?

Sorry for all the Q's but I'd hate to ruin a perfectally good AR for lack of knoweledge

thanks
ka
Link Posted: 9/29/2004 5:45:59 AM EST
Some get by without them, some don't.

My theory is your're blowing hundreds of dollars on this device known to have some reliability issues if not assembled properly, why add another unknown to the equation to save $20?
Link Posted: 9/29/2004 7:00:43 AM EST
I have no problem with spending the extra $$$, I was just wondering if they were a cure for a non-existant problem like the Oly pneumatic buffer, the Rhino gas system, or the accu-wedge.

Thanks

ka
Link Posted: 9/29/2004 7:39:15 AM EST
It is a "CAR" style buffer.... weighs approx the same as the std rifle buffer, soooo, use the crrect buffer fot the stock used.

When doing full-auto with CAR type stock, weight will be a factor.
Link Posted: 9/29/2004 7:49:56 AM EST
I have used the standard car and rifle buffer with no problems. I figured I would buy the 9mm buffer if I started to have problems, but I never did.
Link Posted: 9/29/2004 7:50:12 AM EST
Someone here built a .45 upper on a Cav Arms lower. After very little shooting, the lower broke completely in half ! It transpired that he was using a standard .223 CAR buffer, which is far too light. Conclusion: use the correct buffer or suffer the consequences.
Link Posted: 9/29/2004 7:53:12 AM EST
Kingairpilot,
There are numerous things that a heavy buffer will do for the performance of a carbine or SBR AR15/M16.
The problems are all related to the activity created when the gas port was moved back closer to the chamber on these shorter barrelled guns.

This changed the cycle timing, and made certain things less reliable and more prone to wear/breakage, due to high pressures at the gas port, and in the cartridge case during firing. It is all a pretty well-known subject, and there have been numerous threads related to this.

Adding a heavier buffer will slighly delay the timing of the opening of the bolt. This allows pressures to drop a little more before the bolt tries to open an pull a pressurized case out of the chamber. You may have read some threads about "case heads ripped off", or other failures to extract.

It will also slow the cycling speed, so that there is less chance of "bolt bounce", and the higher momentum of the heavy buffer will assist closing the action if it is dirty, as it comes forward.

Generally it stops the bolt bounce, double-feeds caused by violent cycling, improves extraction reliability, and feeding reliability.

If you use weak loads, a real heavy buffer may not cycle properly. In addition to the heavy buffer, it is common practice to install an extractor improvment device to help with difficult extraction in carbines. In SBR guns, many times a fat gas tube, or adjustable gas tube are used to tame the gas pressures being sent back into the action to further help with cycling speed reduction.
Link Posted: 9/29/2004 8:46:18 AM EST

Originally Posted By twl:
Kingairpilot,
There are numerous things that a heavy buffer will do for the performance of a carbine or SBR AR15/M16.
The problems are all related to the activity created when the gas port was moved back closer to the chamber on these shorter barrelled guns.



IIRC (I don't actually HAVE the 9mm upper yet) the 9mm system is a direct blow back operated system. Does all of this apply to a non-gas type of weapon?

I understand the basic concept of the buffer, and Newton's Laws but have not given much thought to how much energy the locking lugs on teh bolt absorb.

Thanks for all of the replys and keep em comming.

ka
Link Posted: 9/29/2004 5:38:21 PM EST
YES! Use the heavy 9mm buffer.

Running a standard CAR buffer with a telestock 9mm system will eventually ruin your reciever. In fact, I have been running a heavy buffer in my Bushmaster 5.56mm with excellent reliablity for a few years.
Link Posted: 9/29/2004 7:58:07 PM EST

Originally Posted By TopCrest:
YES! Use the heavy 9mm buffer.

Running a standard CAR buffer with a telestock 9mm system will eventually ruin your reciever. In fact, I have been running a heavy buffer in my Bushmaster 5.56mm with excellent reliablity for a few years.



Did someone steal my login info? I have no recollection whatsoever of making that post. Nor do I own a Bushy 5.56. Nor would I use that kinda language.

wtf, over?
Link Posted: 9/29/2004 8:47:12 PM EST
Hey! I didn't post that .... Stop it!.... Huh? You talking to me?
Link Posted: 9/30/2004 4:47:01 AM EST
I am left handed and get some hot gases blown into my face while shooting pistol calibier uppers. I added a heavier 9mm buffer to delay blow-back slightly and it seems to help.

Link Posted: 9/30/2004 7:01:42 AM EST
I few years ago I bought a 5.56 lower w/ a Colt 9mm upper on it. It had a black CAR buffer. Does this designate it as a 9mm buffer, or does color not matter?

It seems to be the same weight, length, etc. as a regular 5.56 CAR buffer, but it's black instead of the normal silvery color.
Link Posted: 9/30/2004 7:26:49 AM EST
Weigh it..... Post office clerk' scale works fine. If 2.9oz, std CAR.... If 3.8oz, "H"..... If 5.6oz, it's a "9mm" buffer.

I had clerk weigh a couple rifle buffers for me to campare weight... 1 was 5.3oz, other was 5.2oz.
Link Posted: 9/30/2004 9:26:21 AM EST
I´m recommending to use 9mm buffer. It works with both 9 or 5.56. It softens recoil with 5.56 and slows bolt speed to normal/ safer levels with 9mm. I wouldn´t care so much of broken lower since those are damn difficult to get here in Finland (= read expensive to get single lower).

Since I´m hobby machinist I make my own. There is few of them in the pic. I even made little improvement on them...



MN
Link Posted: 10/1/2004 5:48:03 AM EST
Is that a gas ring in the bottom pic?
Link Posted: 10/1/2004 12:36:30 PM EST
[Last Edit: 10/1/2004 12:39:13 PM EST by Dehammer]


Originally Posted By TopCrest:
YES! Use the heavy 9mm buffer.

Running a standard CAR buffer with a telestock 9mm system will eventually ruin your reciever. In fact, I have been running a heavy buffer in my Bushmaster 5.56mm with excellent reliablity for a few years.


Did someone steal my login info? I have no recollection whatsoever of making that post. Nor do I own a Bushy 5.56. Nor would I use that kinda language.

wtf, over?



You caught me trying to defraud your good name by spilling out some useful info. I was clever and guessed your password......"hunnybunny"! When ya use someones computer make sure ya clear out passwords and login info, usually browsers remember them the next time you come back.
Link Posted: 10/2/2004 4:54:49 AM EST

Originally Posted By PONY_DRIVER:
Is that a gas ring in the bottom pic?



Ring on the buffer head is made of PTFE to give some lubricity to the buffer. I just did it for the fun of it and because of tight clearances/ tolerances.
Tubes ID is 1", buffer head is .98" and that PTFE ring is .99".

So far that has worked very good. Today I´m going to test it more.

MN
Link Posted: 10/2/2004 7:06:54 PM EST

Originally Posted By M4A2_L073754:

Originally Posted By PONY_DRIVER:
Is that a gas ring in the bottom pic?



Ring on the buffer head is made of PTFE to give some lubricity to the buffer. I just did it for the fun of it and because of tight clearances/ tolerances.
Tubes ID is 1", buffer head is .98" and that PTFE ring is .99".

So far that has worked very good. Today I´m going to test it more.

MN



Most buffers have three chords cut around their largets diameter to reduce friction and/or make it so that water can get out. Also, air wouldn't be trapped so bad by the buffer when the bolt comes back. Not that it would likely affect reliability at the range.
Link Posted: 10/3/2004 6:31:43 AM EST
[Last Edit: 10/3/2004 6:35:24 AM EST by M4A2_L073754]

Originally Posted By 123whisper:

Originally Posted By M4A2_L073754:

Originally Posted By PONY_DRIVER:
Is that a gas ring in the bottom pic?



Ring on the buffer head is made of PTFE to give some lubricity to the buffer. I just did it for the fun of it and because of tight clearances/ tolerances.
Tubes ID is 1", buffer head is .98" and that PTFE ring is .99".

So far that has worked very good. Today I´m going to test it more.

MN



Most buffers have three chords cut around their largets diameter to reduce friction and/or make it so that water can get out.


9mm buffer I copied was purchased from Brownells (made by DPMS) and it has not any chords.


Also, air wouldn't be trapped so bad by the buffer when the bolt comes back. Not that it would likely affect reliability at the range.

Air is compressed, but not that badly and it gets out from drain hole. Today I tested steel buffer on both. 5.56 and 9mm and there wasn´t single failure of any kind.

MN
Link Posted: 10/4/2004 11:35:19 AM EST

Originally Posted By SBR7_11:
Weigh it..... Post office clerk' scale works fine. If 2.9oz, std CAR.... If 3.8oz, "H"..... If 5.6oz, it's a "9mm" buffer.

I had clerk weigh a couple rifle buffers for me to campare weight... 1 was 5.3oz, other was 5.2oz.



I don't have a good scale handy. My kitchen scale isn't sensitive enough, and my reloading scale won't register anywhere near that high. Perhaps a trip to the post office is in order.

Both buffers feel pretty close in weight, so I'm guessing it's NOT a 9mm buffer. I'll add that to my list of things to pick up in the future.

Could the heavier buffer prevent feed problems? My rounds have a tendency to nosedive, particularly with my Uzi mag. The bullet tip will hit on the barrel nut just below the chamber instead of feeding all the way in, which often results in bullet setback. Runs pretty good with the Colt mag, though.

Thanks,
SC
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