What would make one round harder to chamber than another. Some of my reloads seem to be harder to turn the bolt down on than others, nothing excessive but noticeable. Is this the length of the brass, or maybe the thickness of the neck? Never noticed this on any factory ammo so I'm just tryin to make sure I don't screw something up.

Once-fired and resized ammo will be a closer custom fit to the particular chamber than the minimum sized factory or new brass. The probable cause is the case shoulder fitting more snugly into the chamber's dimensions.

You should always check once-fired brass for length and trim all back to the shortest length of the batch when you begin to reload them. Then, keep an eye on them by checking at each reloading session to assure none have grown to maximum recommended length. When they do, retrim.

Another variable is neck thickness growth as the cartridges are fired and the brass with it's tendency to flow from the body to the shoulder/neck area. Thicker necks will be more restrictive to chambering as the outside dimension will be larger than normal, seating the standard diameter bullet into the case. Military brass will have thicker cases than commercial.

Sometimes the bullets provided by the manufacturer can be a bit larger than what's printed on the box. Might want to mike some that you're using to assure they are of the proper OD.

If you are bothered by the fit, you can adjust your dies down to bump the shoulder of the case a bit more - this usually takes care of tight bolt closure.

A bit of chambering resistance is usually desired by benchrest shooters, as they feel this is providing the best relationship between chamber and case dimensions, plus assuring proper headspacing.

One problem might be varriances in the OAL (Overall Average Length) of the cartridge. forgive me if I state the obvious or you already know this, but are all your loads the same OAL? Another problem might be accessive crimping, but since I notice you are using a bolt gun, you probably didn't crimp your loads. Another reason might be mixed brands of brass, where some might have different thickness of walls or neck. Are all you cases the same? Some of your cases might be suffering from bulges at the head of the case, too. --Mykal