Thread: 22lr Resizing/Hollow Pointing Tool

Reforming the profile and adding a hollow point will improve accuracey in some firearms but be detrimental in others.
Borrowed from another site
A Sporting .22 LR chamber is .8751 in length from the bottom of the rim to the top of the throat compared to .6876 for the Match chamber. The length of the Sporting chamber from the top of the rim to the start of throat is .818 compared to .643.

The Sporting chamber at the base of the cartridge is .2307 wide compared to .2267 for the Match chamber. At the throat the dimension of the Sporting chamber is .227 versus .2248 for the Match chamber.

Rim thickness in both is .043 min and .051 maximum.

What this means is that the sporting chamber is substantially larger than a match chamber designed to shoot high quality ammo. High quality ammo, despite being produced to tighter specs may not shoot well in larger "Sporting" chambers due to improper headspacing, chamber slop, etc.

What it also means is that low quality ammo may not even fit in match chambers because it is designed to be oversized at the factory to fit sporting chambers. Find the right ammo for your sporter and you may be able shoot good groups with a sporter.

Buy a rifle with a "Match" chamber, use high quality match ammo and you will be able to shoot tiny groups. Match ammo has very consistent rim thicknesses, powder charges, bullet seating, bullet weight, bullet length, etc. A match chamber gives you the potential to shoot championship groups.

There are "accuracy nuts" who have found very the most dimensionally perfect ammo for their Sporting chambers allowing them to shoot small groups. The variable comes in when there are inconsistencies in the ammo.

Dimensions from SAAMI and published in the Small Caliber News, Winter Edition 2003. Vol. 6 No. 4.

As a chamber reamer wears in barrel production the chamber tightens . profiling a 22lr bullet may shoot well in one rifle and in another of the same type not. The Norinco JW15 and the Ruger 10/22 are examples that I have owned that have demonstrated this inconsistency