Chambers...
All of the 1710 rifles have an optimized match chamber. The description listed here was taken from the US website. As the 1710 is a magazine fed rifle, both chambers are an optimized match chamber for magazine feeding rather than a single shot (no magazine) match rifle. This is common on all 1710's.
Keep in mind, an Anschutz chamber on a single shot match rifle (not magazine fed) such as an Anschutz 1913 can be made tighter than a magazine fed rifle as it does not have to contend with possible loading/feeding issues from
the magazine. All Anschutz chambers meet European CIP specification rather than US SAMMI spec standards.
Both of these models have to meet the same QA standard for accuracy when test fired at the factory...10 shot group less than 18mm in diameter 50m. For comparison a 1913 or a 54.30 match rifle must be less than 15mm for a 10 shot group at 50m. 3mm difference. I just pulled two random rifles out. In the attached photo, the 20" Stainless and a 23" blued
The Stainless S/N 3190057 measures 16.93 in diameter, the 23" blued measures 16.67 in diameter. Similar pattern. As well, anyone who owns a 1710 will attest to having much tighter groupings than their factory supplied test target.
The right ammo will make a huge difference in your accuracy with these rifles.
Barrel size and SS/Threaded...
No difference in accuracy standard. I think this all comes down to aesthetics and personal choice.
Triggers...
Again, personal choice on this one. Both triggers are amazing... typical Anschutz quality. Others who compete in PRS can chime in on the pros or cons on the weights and what they like/dislike. Some prefer a very light trigger and some prefer a heavier trigger.