Shooting technical expert
After 45 years of reloading rifle ammo, I hope I can help with this. It always surprises me that readers don’t ask questions about reloading but maybe there isn’t sufficient interest?

Or maybe they just don’t realise that Sporting Gun has a tame Rifle Loony who can deal with it?

Your own problem is delightfully simple. There are a number of gadgets for measuring the maximum overall length (OAL) of cartridge which an individual rifle will accept but I seem to be able to get perfectly good results in sporting rifles by doing the necessary measurements with a cleaning rod.

1. Take a bullet of the type you wish to reload and drop it carefully into the rifle’s chamber so it falls straight in and stops when it meets the rifling.

2. Put the rifle down carefully, so as not to dislodge the bullet.

3. Hold the bullet in place against the rifling with a pencil or length of suitable diameter dowell.

4. With the other hand, push a cleaning rod in from the muzzle until it contacts the nose of the bullet.

5. Carefully mark the cleaning rod level with the muzzle. You can do this with a sharp pencil or a very fine marker pen.

6. Push out the bullet and then withdraw the cleaning rod.

7. Put the bolt back in the rifle and chamber a round of ammunition. For obvious reasons, it is best to use a dummy round made up without primer or powder. The type of bullet in the dummy round doesn’t matter at this stage.

8. Insert the cleaning rod again until it rests on the nose of the new bullet and make a second mark level with the muzzle.

9. Measure the distance between the two marks on the cleaning rod and also measure the OAL of the cartridge you have just used in the chamber.

10. Add the two measurements together and there is your maximum OAL for that bullet in that rifle’s chamber. Subtract .020” to allow a bit of clearance – and Bob’s your Uncle.

11. Make up two or three dummy rounds to the calculated OAL and see if they will fit in the magazine and also feed smoothly and easily from magazine to chamber. If they don’t, you will either have to load them one at a time or reduce the OAL until they do work through the magazine.