I have been using a bag of lead shot for about the last 10 years or so and on the bench I use it for any calibre, even a 243.

The leather bag has about 15 pounds of lead and it about 2/3rds fills the bag. I sit the bag on a flat sand back that is behind the butt. The butt of the gun is resting against the top 1/3rd or so of the bag so length of pull is not much different.

Once you get use to the bag it is very easy to use and I can even set up to use it across the bonnet of the car. Point of impact is basically the same with and without the bag.

My problem was my neck and it was caused by doing a lot of shooting with both 300 Win and 375 from both the bench and across bags on the bonnet of the car and using a loose hold.

A poster on AR, John S, has a strap that goes around the butt and a section over the top so it does not fall down. Either end of the strap is attached to bags of lead shot.

I also have another lead bag of shot which is much bigger and weighs about 50 pounds. If I use this bag I more or less put my arm pit over the top of the bag. With this one you don't feel a thing and can shoot a 375 or 458 until the barrel melts.

Wish I had started doing it 20 years ago.

If you do a lot of big bore shooting I think the people that have to be careful are those who are not bothered by the recoil. I was like that but it comes against you simply because you can fire so many shots. On the other hand my best shooting mate really feels recoil badly. He does not flinch and can shoot a bigger gun but it just plain hurts him. Probably to do with the shape of is shoulder or whatever. In his case this is good because he can never damage himself since he is so limited in the number of shots he can fire.

Mike