I dont know if it is by choice or chance, but the Ewbanks receivers are tight in all dimensions. That is, you may have to trim metal in several places, but never have the need to add metal. Although this means extra work for the builder, I see it as a good thing. The kits we are using were produced in various countries/arsenals over a period of decades. They will have variances. One reason I prefer the Ewbanks receivers is because I know that they will never be too loose. I like to trim my receivers to fit just right. But before anyone accuses me of being a Joeken plant or stooge, let it be known that I am disappointed in their ability to ship what I ordered. It took about 2 months, 6 shipments and twice as many phone calls before I finally got everything I ordered. They were always decent to me on the phone, but jeez, what a screwed up shipping department.