Is there any good methods of checking the condition of your bore without a borescope. I have a Howa 1500 in 243 win that seems to be falling off accuracy wise. When I got my load dialed in it would shoot .5 consistently with the occasional .25 group. Now it seem to be more in the 1.5 area. Don’t have a round count but would guess 800-1000 down the tube. Would like to check it before rebarreling.