Carbine buffer tube vs rifle length buffer tube difference?

[Tech]

Why exactly is a rifle length buffer tube longer than a carbine tube? I understand that the pressure is less at the rifle length gas port. Is the rifle length tube, buffer, and spring matched to the different pressure? Is the carbine tube shorter just for shorter stocks?

I have a friend that modified his bolt carrier and upper for a side charge handle. He has a rifle length gas system, and a carbine length tube, buffer,and spring. I believe the added weight of the charging handle on the bolt carrier is not letting it cycle properly. It won't lock back on empty mag.

I put my LMOS silent captured spring assembly in his rifle to test it, and it cycled and locked back then.

 

[Fleche]

http://thearguys.com/ar-facts/difference-ar-15-buffers/

 

[Tuflehundon]

It's not so much to do with the gas port, it's all about length. Rifle length was the original size of the tube and buffer. Then they wanted to add an adjustable stock and be able to make it shorter, so they came out with carbine length which uses a different spring and shorter buffer.

You can run a rifle length or carbine length buffer system with any barrel and gas length.

When you start to change the weights of the bolt carrier or buffer systems, you can run into reliability issues because you are taking the weight out of balance. He'll need to experiment with buffer weights to make it reliable. Heavier buffer may work, or it may need a lighter buffer. If your JPSCS worked in his, he may need less buffer weight. He could just take one buffer weight out at a time until you figure out the correct weight to get it running.

A lot of companies that make side charger conversions were the charger attaches to the bolt will take weight out of the bolt equal to what they add with the charger.

 

[Tech]

It's not so much to do with the gas port, it's all about length. Rifle length was the original size of the tube and buffer. Then they wanted to add an adjustable stock and be able to make it shorter, so they came out with carbine length which uses a different spring and shorter buffer.

You can run a rifle length or carbine length buffer system with any barrel and gas length.

When you start to change the weights of the bolt carrier or buffer systems, you can run into reliability issues because you are taking the weight out of balance. He'll need to experiment with buffer weights to make it reliable. Heavier buffer may work, or it may need a lighter buffer. If your JPSCS worked in his, he may need less buffer weight. He could just take one buffer weight out at a time until you figure out the correct weight to get it running.

A lot of companies that make side charger conversions were the charger attaches to the bolt will take weight out of the bolt equal to what they add with the charger.

Thanks. That answers my question. I didn't know if the different lengths spring and buffers were for functionality of the system, or just for different stock length.
I told him yesterday that he probably needed to take material off the bolt carrier or weight out of the buffer. He ended up taking all of the weights out of the carbine buffer and it worked. The weights were about the same weight as the charging handle he made out of an A2 flash hider. He also milled a couple more slots in the flash hider where it's solid on the bottom to reduce weight in the charging handle.

It turned out pretty good, if it doesn't blow up!

 

[Tuflehundon]

He also could have just added a Devil Dog Concepts Hard Charger. It's a charging handle replacement that does not effect system weight, and will work with any bolt carrier.

http://shop.devildogconcepts.com/products/hard-charger

I've been running one on my 3gun rifle for a year and a half now. I won't buy any other brand of charging handle now.