I need a barrel weight or two to play with. I have an Anschutz 54 and the barrell is slightly larger at the end where the old globe front sight mounts and the 54 has a raised platform for that sight so the weight would need to slide over that platform or break into two halves and tightened around the thinner part behind the front sight area. Is this a custom item?

I think it is. Be carefull where you place the weights because they will affect your group placement and size. They work as a tuner and very little movement of them makes a difference.

No they are not custom. Precision Shooters had an article on them and I had on for my other rifle. I'll see if I can find the link to the article and post the web site or his phone number.

OK found it. Here is the one of the ones I had used;
http://www.henrich3.com/smallbore_vib_cont.htm

Just a word of caution. The rules state that the weights must be symetrical so you can't add the extra side weights that are shown with this product.