How to set up rifle buffer on 9mm PCC?

[ReluctantDecoy]

Hi all. I'm trying something that many would advise against, but I want to use a rifle buffer tube on a 9mm PCC because I want the extra length of pull without adding pads on the butt stock. Is all that is needed a buffer tube spacer, and then I can use the carbine sized PCC buffer and spring, or is there actual math involved with calculating lengths and weights? For once in my life, I'm trying to sort it out before buying the wrong parts.

 

[jayhitek]

If your game plan is to use the same lower with different caliber uppers..
You can use the normal rifle buffer tube you would use with a 556 or 300 as the 9mm etc. ie Leave the lower as is but only have to tweak the magwell.
But then all you need to do is swap out the buffer spring, spacer, and buffer in the lower when you switch uppers. That is what I do.

And they sell a special combo just for 9mm. Just like this. You can find cheaper or better elsewhere, but Brownells was just the first to pop up.

ANGSTADT ARMS, LLC AR-15 9MM BUFFER KIT | Brownells

The Angstadt Arms 9mm AR-15 Buffer Kit provides the correct weight and size buffer for reliable cycling of your 9mm blowback AR-15. Just in case you ask: the standard rifle or carbine buffer isn’t the correct weight for an AR-15 chambered for 9mm ...

www.brownells.com

 

[DW357]

@SJan might have some advice

 

[ReluctantDecoy]

If your game plan is to use the same lower with different caliber uppers..
You can use the normal rifle buffer tube you would use with a 556 or 300 as the 9mm etc. ie Leave the lower as is but only have to tweak the magwell.
But then all you need to do is swap out the buffer spring, spacer, and buffer in the lower when you switch uppers. That is what I do.

And they sell a special combo just for 9mm. Just like this. You can find cheaper or better elsewhere, but Brownells was just the first to pop up.

ANGSTADT ARMS, LLC AR-15 9MM BUFFER KIT | Brownells

The Angstadt Arms 9mm AR-15 Buffer Kit provides the correct weight and size buffer for reliable cycling of your 9mm blowback AR-15. Just in case you ask: the standard rifle or carbine buffer isn’t the correct weight for an AR-15 chambered for 9mm ...

www.brownells.com

Sorry--I really should have given more detail. I'm piecing together a 9mm PCC using a dedicated glock mag lower. This would be the first for me, and I know these systems can be finicky over buffers, particularly when going unconventional with the rifle length buffer tube.

 

[jayhitek]

Sorry--I really should have given more detail. I'm piecing together a 9mm PCC using a dedicated glock mag lower. This would be the first for me, and I know these systems can be finicky over buffers, particularly when going unconventional with the rifle length buffer tube.

My advice would be to go with the 9mm buffer kit then. It's designed for the AR9 rifle.
The buffer is very heavy.

 

[ReluctantDecoy]

My advice would be to go with the 9mm buffer kit then. It's designed for the AR9 rifle.

Definitely using a dedicated AR9 PCC buffer and spring, but I think I'm going to need something like a spacer with the rifle length buffer tube. Or so I have read, but I'm having trouble getting the specifics. This is one such suggested item from another forum, but I wanted to see what people here would say:

ROCK RIVER ARMS AR-15/M16 FIXED STOCK TO CARBINE SPACER | Brownells

Spacer – Machined Delrin. 2-5⁄8" (5.4cm) long. Fits buffer tube for standard, fixed A1/A2-style AR-15/M16 buttstock.

www.brownells.com

 

[shootymacshootface]

Your on the right track. Use the 9mm buffer parts and drop some quarters in the spring tube until the bolt only goes about 1/8" past the bolt stop, then measure the stack of quarters and cut a piece of 1" delrin rod to your stacked quarters measurement. That will be your spacer. I don't recommend leaving the quarters in there permanently because they will eventually deform and the spring can work its way around them.

 

[ReluctantDecoy]

Your on the right track. Use the 9mm buffer parts and drop some quarters in the spring tube until the bolt only goes about 1/8" past the bolt stop, then measure the stack of quarters and cut a piece of 1" delrin rod to your stacked quarters measurement. That will be your spacer. I don't recommend leaving the quarters in there permanently because they will eventually deform and the spring can work its way around them.

Nice! Thanks for this info. This is a huge help.

 

[shootymacshootface]

One other useful tip is to not install the buffer retaining pin. It makes life a lot easier, just remember to put a finger in front of the buffer as you open the action.

 

[jayhitek]

The kit comes with the proper spacer..

 

[ReluctantDecoy]

The kit comes with the proper spacer..

Maybe, but it notes it is a carbine buffer set up. This is a rifle buffer tube. There's a good amount more length to the rifle tube. A carbine buffer space might work or could still be too short. Although, that's why I'm here asking, so if someone has made this kit work on a rifle buffer tube, then I'm all ears.

 

[jayhitek]

Maybe, but it notes it is a carbine buffer set up. This is a rifle buffer tube. There's a good amount more length to the rifle tube. A carbine buffer space might work or could still be too short. Although, that's why I'm here asking, so if someone has made this kit work on a rifle buffer tube, then I'm all ears.

You're right. Good point.
I forgot I have carbine length not rifle length.

 

[hv55maxx]

Hi all. I'm trying something that many would advise against, but I want to use a rifle buffer tube on a 9mm PCC because I want the extra length of pull without adding pads on the butt stock. Is all that is needed a buffer tube spacer, and then I can use the carbine sized PCC buffer and spring, or is there actual math involved with calculating lengths and weights? For once in my life, I'm trying to sort it out before buying the wrong parts.

Billet Rifle Stock Buffer Spacer (to use ST-T buffers in A1/A2 stocks)

Spacer for a rifle buffer tube to allow the use of a carbine buffer spring and buffer. The spacer is easily removed and requires absolutely zero gunsmithing. Just pop it in, replace the buffer and spring, and shoot. NOTE: Non Refundable item.

www.spikestactical.com

 

[ReluctantDecoy]

Billet Rifle Stock Buffer Spacer (to use ST-T buffers in A1/A2 stocks)

Spacer for a rifle buffer tube to allow the use of a carbine buffer spring and buffer. The spacer is easily removed and requires absolutely zero gunsmithing. Just pop it in, replace the buffer and spring, and shoot. NOTE: Non Refundable item.

www.spikestactical.com

Thanks. Are these just blocks that take up extra space? Wondering how well a 3D printed block at 100% infill would handle this considering I'd save myself up to $30. on it. Or figuring out the space requirement with quarters as shooty suggested and casting a resin mold. I could then get creative on cast material like this dense rubber I have that comes out like a hockey puck.

 

[jayhitek]

Thanks. Are these just blocks that take up extra space? Wondering how well a 3D printed block at 100% infill would handle this considering I'd save myself up to $30. on it. Or figuring out the space requirement with quarters as shooty suggested and casting a resin mold. I could then get creative on cast material like this dense rubber I have that comes out like a hockey puck.

This sounds like a great idea! Go 3D at 100%
Just need to find out the dimensions.

 

[hv55maxx]

Thanks. Are these just blocks that take up extra space? Wondering how well a 3D printed block at 100% infill would handle this considering I'd save myself up to $30. on it. Or figuring out the space requirement with quarters as shooty suggested and casting a resin mold. I could then get creative on cast material like this dense rubber I have that comes out like a hockey puck.

Yeah just eats up space in a rifle buffer tube to allow the use of carbine buffer and spring. even works on LR308. If you have a cheaper option, by all means, do it. I dont personally have a 3d printer so click and ship worked for me.

 

[ReluctantDecoy]

Yeah just eats up space in a rifle buffer tube to allow the use of carbine buffer and spring. even works on LR308. If you have a cheaper option, by all means, do it. I dont personally have a 3d printer so click and ship worked for me.

There is a good chance that at even 100% ABS infill that blowback force will eventually compress the print, but it might be worth testing just for curiosity sake. I just didn't know if there was some type of innate compression value to the blocks you guys were showing me that I was unaware of, but it appears that everyone here is saying they are just space fillers (which is good news for my testing).

 

[jayhitek]

The spacer that came with my buffer kit is just a hard piece of plastic.
You could also try the resin mold if the 3D print fails.

 

[Uzi2]

Disregard..

 

[shootymacshootface]

He will still need a spacer in a rifle length tube.

 

[ReluctantDecoy]

Save some aggrivation and get one of these and be done.View attachment 316502

Using it will prevent this. VVVVVVVVVVVVVV from ever happening.View attachment 316500

Ok. Now I'm getting confused here. I think what you're showing me is a PCC buffer. And that's what I was planning to use. The question was whether I need a spacer to use a PCC carbine buffer for a rifle buffer tube. Are you saying this one PCC carbine buffer acts as both?

 

[shootymacshootface]

That buffer is the right length in a carbine tube.

 

[ReluctantDecoy]

He will still need a spacer in a rifle length tube.

Thank you. I think people are taking the initial question as just "do I need a PCC buffer". Maybe I worded it wrong.

 

[shootymacshootface]

A lot of people don't read everything when a thread gets long.