You can use either a rifle length buffer tube or carbine buffer tube and the length of the buffer tube determines which spring and buffer.
For example you can use a fixed stock with a rifle buffer tube, rifle buffer and rifle length buffer spring. You can also use a carbine length buffer tube with a butt stock of your choice. Use a carbine length spring and buffer but some people prefer to use a heavier buffer like an H-2.
If your using a suppressor I suggest you use an adjustable gas block or and adjustable bolt carrier or adjustable carrier gas key like rubber city armory.
https://www.rainierarms.com/rubber-city-...e-gas-key/
https://bootleginc.com/product/full-auto...e-carrier/
The most common AR-15 6.5 Grendel barrel to be over gassed are the 18”. This can be because of oversized gas ports used by some manufacturers but is also due to dwell time on midlength gas port barrels. If you use a suppressor on an 18” barrel it adds to the dwell time and affects timing of the action. Several manufacturers are selling 18” barrels with intermediate or rifle length gas system to better balance 18” barrel.
I have an 18” midlength gas Faxon Group Buy 6.5 Grendel barrel with a fixed gas block. This gun has functioned 100% and is not over gassed. The barrel has the appropriate size gas port but I don’t use suppressors.
Several forum members like the JP silent captured spring but the are more expensive. The light weight bolt carriers should be used with adjustable gas blocks.
For example you can use a fixed stock with a rifle buffer tube, rifle buffer and rifle length buffer spring. You can also use a carbine length buffer tube with a butt stock of your choice. Use a carbine length spring and buffer but some people prefer to use a heavier buffer like an H-2.
If your using a suppressor I suggest you use an adjustable gas block or and adjustable bolt carrier or adjustable carrier gas key like rubber city armory.
https://www.rainierarms.com/rubber-city-...e-gas-key/
https://bootleginc.com/product/full-auto...e-carrier/
The most common AR-15 6.5 Grendel barrel to be over gassed are the 18”. This can be because of oversized gas ports used by some manufacturers but is also due to dwell time on midlength gas port barrels. If you use a suppressor on an 18” barrel it adds to the dwell time and affects timing of the action. Several manufacturers are selling 18” barrels with intermediate or rifle length gas system to better balance 18” barrel.
I have an 18” midlength gas Faxon Group Buy 6.5 Grendel barrel with a fixed gas block. This gun has functioned 100% and is not over gassed. The barrel has the appropriate size gas port but I don’t use suppressors.
Several forum members like the JP silent captured spring but the are more expensive. The light weight bolt carriers should be used with adjustable gas blocks.