Heavier Buffer Question AR9

[Moondog1]

Are there any quarters or spacers of any type in the tube?

I had quarters with the PSA ar10 spring and H buffer, but the 7.5 ounce buffer won't fit with any combination of springs I have without any quarters. I don't think there is anything else in the buffer tube. I'll shine a light down there this evening to make sure.

I'm new to messing with buffers and springs... so don't hold this against me...I had a cheap unknown extra carbine spring to play with. I shortened/hacked it up quite a bit and still could not make the 7.5 ounce buffer and bolt go rearward enough to engage the LRBHO. The return pressure on the spring was really weak, it was funny how slow it closed the bolt.

 

[Moondog1]

Since you asked what I would do: if you want to try something, try the buffer with the factory spring. See if it will hand function/cycle first, if so, go shoot it. I would not care if the bolt locks on the last round.

Then, try it with just the new spring and factory buffer. Then try them both together. I am thinking that the two new parts will combine to prevent the gun from cycling.

The easiest way to tune it would be with hand loaded ammo and the factory setup.

If I may ask, what are you hoping to change about the gun?

I will try the new 7.5 ounce buffer with the factory spring, but I think I did and the bolt would still not go rearward enough to engage the LRBHO. I will make sure this evening though. I did not try the new spring and factory buffer though, I will definitely try that.

I've been running(for 150-200 rounds or so) the PSA ar10 spring and PSA H buffer with good results. It had smoother recoil and seemed to be less gas. That's what prompted me to order the big 7.5 ounce buffer and $5 spring that came with it as an option.

What I'm trying to change is smoothness with running suppressed, amount of gas/noise at the bolt. I understand the limitations of it being a blow back, but I think it's really over gassed with a suppressor on it. I think if I were left handed I would never own a blowback PCC, my friend got his dirty blonde beard painted black the other day by all the crap coming out of the port as a left! It was pretty funny. So mainly, I'm just playing/tinkering/experimenting. If it runs better with a 5 ounce plus buffer then that's what I'd like to run. But I haven't put enough buffer in it to make it choke or not have the last round lock the bolt open with the two buffers I've tested, standard/factory carbine buffer & the PSA AR10 buffer marked H.

 

[Moondog1]

Is the plastic bumper on the old one the same diameter as the new one. If it is but shorter you might try swapping them.

I think they are the same size from eye balling them. So ideally, does that always hit the rear of the buffer tube? If it does then I think my new bolt will be too long no matter what spring I'm running.

 

[HfdSARG]

Another thing to try is take the spring off the new buffer and drop just the buffer down the tube. Put the two halves back together point muzzle up and let the carrier fall. If it clears the latch the buffer is not too long. You will have to turn it muzzle down and let the carrier fall by gravity before you can separate the two halves.

 

[1006]

If you are reloading your own: try the faster powders, they make less gass.

I used to run 3.0 Titegroup with a 158LRN 38super bullet in a Marlin Camp 9. The velocity was measured ar 1025fps. It was quiet without a suppressor.

 

[1006]

The local stores used to carry an Atlanta Arms product that was a 147 FMJ; it was loaded pretty light for competition shooters if I remember correctly.

 

[Moondog1]

Another thing to try is take the spring off the new buffer and drop just the buffer down the tube. Put the two halves back together point muzzle up and let the carrier fall. If it clears the latch the buffer is not too long. You will have to turn it muzzle down and let the carrier fall by gravity before you can separate the two halves.

So I did that this morning and it cleared the bolt hold open! Which is what made me start snipping coils off an extra spring I had. So I guess I could get the spring short enough to clear the LRBHO but it would have zero pressure to return the bolt home, right? Thanks for all the info and helping me with this stuff!

 

[MegaFan]

I got 1.25 worth the quarters in my buffer tube lol

Just remember, when you go to trade, it's got to be worth at least a buck and a quarter or don't do the deal!!

 

[HfdSARG]

Clipping the spring will negate the heavier buffer. Yes it would decrease the return force. With the extra power spring you could spare a little, mabey!!!You might try calling KVP and see if they have heard of this happening and recommendation. It's possible the head of the buffer where the spring rests was made too long. They make it longer on purpose to get rid of overtravel, possibly got rid of too much overtravel.

 

[Spikey]

I've had very good luck with Freedom Munitions 147 gr subsonic. Light load 950 fps Works great in 6 different guns and four different suppressors