My brother and I both have Thompson Encores with a couple barrels each. I went with the stainless steel setup and the synthetic stocks while my brother went with blued barrels and walnut stocks. I have barrels in .308 and .223, and he has .280, .22-250, and .22 Hornet. While I have not had any issues with my setup, my brother started having accuracy issues with his a few years ago. Of all the times to start, he first noticed it during deer season when he missed gimme shots on two different animals with his .280. He finished out the season using a different gun, but after the season, he and my dad tried to figure out the issue with that barrel.
They started by checking if the gun was still sighted in, even though that had checked that before the season. They played around with that thinking that the scope was off, but as soon as they thought they had it sighted in, their point of impact would change. Next, they thought the either the scope base or the scope mounts were loose. After completely re-mounting the scope base, scope mounts, and scope, they went back to sighting it in. Again, the same thing was happening where they thought they had it sighted in only to have the point of impact change again. They did wait for the barrel to cool between shoots, they used proper cleaning techniques, and it did not seem to matter which type of ammo they put through the gun. After doing some more head scratching, they decided that the forend was a little warped, so they sanded out the inside of the forend a bit. After more shooting and cursing, they were still having the same problem with the point of impact moving. Now thoroughly frustrated and completely stumped, this barrel got put in the closet and left untouched for quite a while.
In the meantime, my brother did continue to use his .22-250 and .22 Hornet on his Encore setup without any issues for another year or so. Finally, about a month ago, his .22 Hornet started having the same issues that he was having with the .280 barrel. Thinking that he simply got bad barrels, he was ready to through the entire setup in the trash. Before giving up completely, I convinced my brother that I should shoot his barrels on my setup. Last week, my dad and I finally tested this out. After my dad and I both put a couple shots through his .280 barrel on my Encore receiver. Between the two of us shooting, all of our shots grouped nicely, and we were able to sight it in fine.
After closer inspection of his walnut buttstock, we found tiny crack that ran the entire length of the stock. We think that this crack has been growing over time, and that it was torquing the gun when fired. The heaviest recoil caliber showed symptoms first until the stock weakened enough to show the same symptoms shooting the .22 Hornet.
We are all happy that we finally have it figured out, but it was a ridiculously frustrating experience. My brother is going to get a new Encore Pro Hunter buttstock and forend to fix the problem. I know this was an unnecessarily long story, but has anybody else had a similar experience, particularly with the Encore setup?