It's just disappointing to need to replace parts that aren't worn out, just not properly fitted from the factory.
You said you bought this from Cabela's "Bargain Cave" and that it was a display model. I assume Cabela's staff is the source of the 'display model' moniker.
In no way is that gun considered factory new. Your assumption that the problems with the internal parts are due to improper factory fitting is not supportable.
As a display model, if that's truly the case, it is subject to significant abuse by both members of the shopping public and, unfortunately, retailer staff that don't know what they're doing. Further, there is no information about how long it was a 'display model' or whether it had any other abuse before entering that status.
I think your disappointment is not justified. I'm not surprised you've found problems with a 'Bargain Cave' purchase - I think you should have expected some problems.