SHOOTING IN AT 25M

I would like to comment on the article by Cassie Nienaber: INSKIET OP 25M VS INSKIET OP 100M which was published in the February 2020 edition. My opinion is my own and is based on what I have experienced over the years.

Firstly, the rifles used were actually not “shot-in” at 25m. If they were, they should have printed on the X in the middle of the aiming spot. This is the reason for some of the groupings at 100m. If you “shoot-in” at 25m you must ensure that you hit exactly on the X in the centre of the aiming point to avoid drift at longer distances.

Secondly, the 6mm PPC grouping at 100m is impossible for a rifle set in at 25m. The reason for this is illustrated very well on the picture depicted just above the article on the page. When a rifle is “shot-in” at 25m, the bullet trajectory will rise above the line of sight for some distance (how far depending on the ballistics, bullet weight and shape) before it will cross the line of sight again.

So, for the 6mm PPC to shoot low at 100m means that this rifle was not shot-in correctly. Its grouping at 100m should also not have been used to skew the 100m grouping figures.

I have always followed the guidelines as described in A Hunter’s Handbook to shoot in at 25m for most of my hunting career. When I have zeroed my trusty Musgrave .308 Win at 25m I know I can shoot a bladskoot up to 200m without changing my aiming point.

I would appreciate it if the test can be redone to depict a less bias view. ( Cassie, los liewers die 6mm PPC – daar is ’n groot fout iewers!) ANDRÉ DART

Cassie’s response:

Thanks for reading my article attentively. What I actually wanted to illustrate is that small groupings at 25m will not automatically result in good groups at 100m.

With reference to the use of the 6mm PPC: Telescopes without external parallax adjustment (or not provided for at 25m) combined with a minimum magnification of 4x or more (the higher the worse), often cause large parallax errors at 25m. In other words, you might not really aim where the X-mark is and as a result shots may land up to 35mm away from where you aim due to parallax (eye-position). When distances increase, so will parallax. That’s why I don’t like zeroing rifles at 25m. The 6mm PPC I used is a benchrest rifle fitted with a Leupold (fixed 45x magnification) telescope which is difficult to shoot with at 25m. Even when excluding the 6mm PPC, the groupings of the .260 Rem and .30-06 at 100m are not good enough for hunting.

I see zeroing at 25m as a compromise ONLY. Always test the zero at 100m or your selfimposed maximum hunting distance.