Are you saying that you full-length sized them and then chambered them BEFORE you charged and seated the case and they fit fine, but after you charged and seated the bullets they chamber hard?

If so the first thing that you should look at is your cartridge overall length (COL). It sounds like you haven't seated the bullets far enough into the cases and the bullet is firmly hitting the lands in the bore when you are chambering them. Often when this happens the camming action of the bolt will have enough force to push the bullet back into the case enough to allow the bolt to close.

DO NOT FIRE THAT AMMO!!!

Because the bullet is firmly jammed into the rifling, effectively creating what is basically a bore obstruction that will cause the pressure levels to spike to dangerously high levels possibly resulting in damage to your rifle and serious bodily injury or death to you and any bystanders.

Check to make sure that the bullets are seated to the COL depth stated in the load manual FOR THE BULLET THAT YOU'RE USING. The published COL is guarantees that the bullet (with its perticular ogive shape) will not contact the rifling in a chamber cut to SAAMI specs. If you have already seated the bullets so that they are at the published COL and they are still hitting the rifling, it could be that the throat on your perticular rifle was not reamed deep enough to meet SAAMI specs. At that point I'd either take the gun to a 'smith to have him cast and measure the chamber dimensions (which is the safest course of action), or you can take the riskier route and seat the bullet slightly deeper until the round chamber easily. You will, of course, have to reduce the starting loads by 10-15% and work back up because a deeper seating depth will increase chamber pressures. If you choose the second course of action you do so AT YOUR OWN RISK.

Oh, and one more thing. How are you measuring your cartridges? A caliper accurate to .001" is really a must, especially if you have a short throated chamber. 0.001-.002" can make the difference between a bullet seated to close to the rifling and a bullet seated at optimum seating depth. If you don't have a caliper (dial or digital is your choice), get one. They are worth the $20 investment (If you want to save a bit of money, avoid buying the brand name calipers marketed by the various reloading tool companies like Lyman, RCBS, etc.... They are fine calipers, but you'll pay more for a virtually identical product probably made in the same factory than if you buy an offbrand from one of the online tool distributors. Just a thought).

Good luck and stay safe.

Mike