Home Forums Hunting & Shooting AR and Tactical Rifles I Need a Little Advice, Rifle vs Carbine Buffers and Springs

I recently ordered a complete upper from Palmetto (.223 Wylde) that has a 20 inch barrel and a rifle length gas system. Will it run on one of my lowers that has a carbine buffer and buffer spring? If not, what do I need to change out in my buffer tube (adj stock)? Buffer? Spring? I see "rifle buffers" on line. They appear longer and I guess heavier. I assume there must be "rifle springs". Thanks for your help.

Rifle buffers are heavier but rifle springs are longer and have a different spring rate. They can not be used in a carbine receiver extension.

It's all going to depend on how this barrel is ported. I always start with an H2 buffer and see if it reliably locks the bolt back on the last round with a carbine gas system. For a rifle gas, I'd start with an H buffer.

Just note that a rifle gas has not always been 100% on a carbine lower. That's why VLTOR came up with the V5 receiver extension and a variety of buffers and springs.

I did this before with a 20 inch Fulton Armory upper and a RRA lower, it was the one they advertised as being bought by the DEA but I cannot remember if it was carbine or Midlength gas. Mine worked fine. Try if before you do anything else, put one cartridge in it, fire if it locks back I would just use it also ejection should probably be 3-4:30 range.

I run 2 rifle length gas guns with carbine buffers and no issues.

I haven't had any problems with a carbine buttstock/spring/buffer on a 20" Colt rifle upper.

I always thought it odd that Canada's army fielded 20" guns with carbine lowers but there were trials here that never ran 100%. The V5 system was the first to change all that.

My cousin runs a few rifle gassed guns on carbine lowers and for the most part they run good but we have had to experiment with different springs and buffers to get them just right. Although his have been odd calibers.

Seem to recall reading the C7A2 uses an H2 weight buffer. You might try contacting Colt Canada to see if they will tell you the weight of buffer they use:

http://www.coltcanada.com/upgrades.html

I tested different buffer weights this past year and had better results with the SSS spring over heavy buffer

You can only use a rifle buffer in a rifle receiver extension and that leaves you with a fixed stock. To keep what you've got you can play with buffer weights and spring power to get similar results. Or you can get the VLTOR A5 setup to use a rifle length spring and different buffer weights with a collapsible stock, but it's an expensive setup.

Canada's Colts run H2 buffers in everything.b 20in to 10.5's.