I have three 30-06 Handis, a .35 Whelen, a .243, a 45-70, one Ultra in .223, and a Sportsman in .17HMR. Two 12ga, and one 20. The only fail to fire was the .35 Whelen when it was new. Sent it back to NEF, they fixed it. The Ultra failed to eject every time when new, sent it back to H&R, they fixed it. Have not had one of either since. I'm in the woods two to four days a week, and when I am not in the woods I am at the range. So I do a lot of shooting. These guns are virtually indestructible and fail proof. I breakdown and clean them twice a year, in the fall and spring, usually. Oh I can understand a part breaking every once in a while, but gosh so many people having problems, it's hard to understand.
Maybe one reason I don't have any problems is that I don't do any modifications, I leave them the way they were designed and built. Factory installed barrels, done by the experts.
Now with my 30-06 ammo I am picky, I weigh and sort all the cases and bullets, so they match. I weigh all the powder charges with an electronic scale. I full length resize, measure and trim, all my cases. With the Whelen and .243 I am still shooting factory(They don't get used a lot), no problems there. The 45-70, I just load them using a mechanical powder measure, minimal case prep. How can you screw up 45-70 loads. The .223s since I also use Mini-14s and the wife also uses .223s like they are going out of style, I load them in volume. Again minimal case prep, and mechanical powder measure. I load them to match Winchester factory specs, from the Hodgdon manual, using all Winchester components, with Nosler bullets. They shoot great in the Ultra.
Again I have a hard time understanding all the fail to fire, and fail to eject, problems people are having.
Even my sub-sonic loads for the suppressed 30-06, using Trail Boss, have never had a problem. The one and only thing I do to all my Handis is to put an O-ring under the forearm.