I can’t find anything on an intermediate gas length system, and I’m trying to understand its benefits over mid length or even rifle.
I’m building a SPR in 6.5grendel, and I purchased a Odin 18” Grendel barrel with an intermediate gas length. Can anyone help explain to me it’s intended used and differences?
New to DMR/SPR builds. Thanks in advance.
It's a compromise. Some consider a Midlength gas system on an 18" barrel overgassed (too much pressure for an extended length of time), while a Rifle length gas system on an 18" might not have enough dwell time to function reliably.
The old milspec methodology was to just make sure everything was "overgassed" for reliability in adverse conditions so that you don't have a stoppage when things get dirty/cold/dry/etc, so you'd see Carbine gas systems on everything 16" and shorter. Now that the civilian market is loaded with options, you have companies and competitors seeking out every advantage possible. Most 16" and 14.5" (and some shorter) barrels now commonly have midlength gas systems to reduce the pressure that blows back to cycle the bolt carrier group. Similarly, 18" barrels can commonly be found with midlength or rifle length gas systems.
The Intermediate gas system is popular on 18" rifles with 6.5 Grendel in particular because it smooths out the recoil impulse by putting the gas port where the port pressure will be lower, without reducing reliability by shortening the dwell time as much as a rifle-length system would. As someone else said, as long as the gas port is properly sized, the port location isn't necessarily a deal breaker. With that said, the Intermediate gas system is a good compromise for an 18" barrel. Odin works makes very high quality barrels for the money, so I think you'll be very happy with the rifle you build around this barrel.
FWIW, I have 18" barrels in 5.56 and 6.5 Grendel that have midlength gas systems, and I feel no need to switch them to an Intermediate or Rifle system. Knowing what I know now, I would definitely consider an Intermediate or Rifle length gas system if I had to rebuild them today, but my primary concern would be the quality & reputation of the barrel maker first, with the gas port location second.
Unless the gas port location was integral to the rifle's design, like the Mk12 SPR and its gas block front sight at the Rifle length gas port.
