didn't want to hijack the other t1 thread.
basically want it as a trainer/hunter.
I've noticed shorter barrels are generally louder ive also read a longer barrel doesn't do much for the caliber.
thanks all.
Barrel length -- whether it's 16 or 20" -- in a rifle such as the T1X won't make a significant difference in accuracy when comparing two otherwise equal rifles. The shorter barrel is handier when a suppressor is added or when an extra four inches is too much for some other reason, such as use in the very densest of brush. The T1X is already a smallish rifle. With the 16" barrel it is 33.5" long, with the 20" barrel it is 37.7", just over three feet long. By comparison the CZ 455 American with a 20.5" barrel is 38.2" in length. Even the basic Ruger 10/22 is 37".
As for the barrel length not doing "to much for the caliber," the internet is full of statements that all the powder is burned up in the first 16 or so inches. That may very well be true. But it's largely irrelevant for the purposes of a rifle. Very few rifles designed and made for accuracy will have 16" barrels.
If the thinking is that a slightly higher MV may be achievable with a 16" barrel than 20" it should be weighed against any accuracy it gains. There's no evidence that a round that is going 50 or 100 fps faster than another gives it an accuracy advantage because of that. In short, the shorter barrel will not make it more accurate.
The rifle's accuracy will be the product of the individual barrel it has, not whether it is 16 or 20 inches in length. Barrel quality is not always equal between individual rifles, although most or the vast majority will be average for that model. If higher MV's are sought for another reason, use HV ammo.
What should be important in making a choice between a shorter barrel and one that is a little longer is how the rifle balances, how the rifle feels when at the shoulder. Aesthetic value can be important as well: which does the buyer like better? My own view is that the 16" barrel makes the rifle look too short, but that's only my opinion and should not sway anyone else. Another factor is the weight difference between the 16" model and the 20" model. The shorter rifle is 2.4 kg (5.29 lbs), the longer rifle is 2.6kg (5.73 lbs) -- a .44 lb difference. On an already small and lightweight rifle, the extra weight of the 20" model might be a useful factor. It can help with stability because of the additional inertia.
In the end, pick the rifle that feels the best when you handle it. The 16" barrel in itself doesn't add to the performance of the rifle downrange.