222 reamer

[Bruce W]

What is the best lead angle for 50 / 55 grain flat base bullets. Looking at buying my on reamer. Thanks, Bruce

 

[DaveTooley]

1'-30" is pretty standard for most if not all newer designs.

 

[Bruce W]

Thanks

 

[Ray Gross]

With light bullets in 22 calibers and below, it is common to have more than desired jump with zero free bore.

Desired is of course a relative term, but I get a lot of calls about this subject.

This issue is that the cruel laws of trigonometry will only let the leade get so close to the cartridge case mouth. Or more precisely, the intercept diameter in the leade, i.e. the diameter at which the bullet first touches the leade.

One way of bringing the intercept diameter closer to the case mouth is to use a sharper leade angle. This does two things in combination. The axial length of the leade itself is shorter, which brings the intercept diameter closer. Secondly, a sharper angle reduces the intercept diameter. For example- a bullet that first kisses a 1.5 degree leade at .001 under bullet diameter, would kiss a 2.5 degree leade at a smaller diameter.
How much smaller? Depends on the leade angle and bullet ogive curvature.

If you really want to go crazy, you'll also need to factor in that as the leade angle gets sharper, the intercept diameter gets smaller and thus moves forward at differing rates along the leade angle and ogive curvature.

The short answer is that it is common for small caliber chambers to have greater than 1.5 degree leades just so the short stubby bullets can be seated a reasonable amount into the case neck and not have to jump a mile.