Originally Posted By: HcboyOriginally Posted By: GLShooterI use the Sinclair tool for measuring distance to lands. Fast, accurate and repeatable. It is far easier to use than the Hornady tool that I also have used and you aren't hobbled buying or making the converted cases.
Greg
How does this Sinclair tool work? Is it caliber based? Could this be used for a wildcat round?
Also how important or how beneficial is it to know your distance to the lands? Thanks
The Sinclair uses a FIRED case from YOUR chamber. To make them work slick you size the case down enough to take some of the body expansion out but NOT move the shoulder. No taping etc. First step is drop a bullet in the chamber and get the distance from the action insert to that base. Then you drop the case, after removing the bullet, in the chamber and get a measurement from the rod to the back of the action insert. The rod has stops that have a collar on them. Measure the collar distance add the bullet LENGTH and you have COL for distance to lands. Sinclair/Brownells has a good little video on it's use.
It is made to order for a wildcat as you aren't sending in cases to get tapped ,unless you do them yourself, and ittakes much less finesse in checking the bullet location in the lands. Keep that case for a reference and you will always be ready to measure that chamber. Very nice as you are able to adapt to slight vagaries of chambering. No generic to mess with a sit is rifle specific.
It is extremely important in many chambers to knwo where the lands are if you are dealing with accuracy work. In a wildcat it is imperative as you have no standardized load length unless you determine it yourself. You can' say it's an AR so therefore I can load to 2.260 or XXX. In reality like our 6X6.8 you set the bullet to the chamber. My new 6X6.8 for instance has a 87 VMAX at 2.282 but 87 Varmint BTHP is at 2.251. In the American 30 my MAX col for a 150 Sierra SP was 2.295 but a 110 RN was at 2.008.
Some bullets need different seatings going in. The VLD likes to be uptight on the lands while others like the Barnes need about 0.050 off.(per them)
So yes it is VERY important if dealing with non-SAAMI chambers and even if you are seating in and out is a major step in tuning on several levels. I can assure you that loading every 69 grain SMK in every 223 SAAMI chamber to 2.260 will not get the best performance out of every barrel. Plus remember every time you fire that rifle the throat is altered. Not much but every 500 rounds or so it would behoove one to check the lands distance and maybe move the bullet out a bit more if you can to chase the lands and if you can't maybe change bullets to get the distance you work at back.
Greg