Plain Base VS Boattail Bullets
This topic generates a bit of discussion on the gun boards, usually with participants quoting their favorite drop chart or ballistic software. I have a passing interest in the subject, as it relates to practical distances with common hunting rifles. Drop charts and ballistic calculators can be interesting reading; but I wanted to see holes in paper. I decided to load some ammo with both types of bullets and shoot them at 300 yards. My goal was for the loads to be duplicates in all respects, except for the base profile of the bullet.
Hornady makes boat-tail and plain based Interlock .308 soft-points, both in the 150 grain weight, which are pictured below. The links are loaded with data that don’t mean much to a country boy trying to smash Bambi or Wiley, out across the big pasture.
I’ve used both bullets in the past, but the boat-tail is harder to find locally, so the plain-base 150 grain softpoint is what I typically load.
The test rifle was my Winchester 670 in 30-06 Springfield. Winchester cases and standard large rifle primers were used. The cases had been fired several times and I followed my usual practice of trimming, chamfering and deburring the case mouth along with cleaning the primer pockets. The charge was 50.5 grains of H4895, each charged weighed and trickled right up to the line. The 20″ Winchester produces 2850 fps with this charge, using the plain-based 150 grain bullet. Both bullets were seated to the top edge of the cannelure and crimped with a Lee Factory Crimp Die.
I am still using That 70’s Scope so I arranged a target with an easily visible aiming point… didn’t think to grab a photo of it until after I’d shot a group, though. POA was the center of the picnic bowl.
Now there is no trouble too great when doing scientific work for my readers, so I shot from the finest rest available… a 5 gallon bucket stacked on sandbags in the old haywagon, with a range bag thrown on top. Distance between the haywagon and the log backstop is just over 300 yards.
Here’s the results. With a 200 yard zero, the plain-based load printed a 3″ group right below the bowl, but I had a ‘high’ called flyer in that group.
The BTSP load printed inside 2 1/4″. All three shots with the BTSP load looked pretty good when the trigger broke.
The center of the BTSP group was exactly 3″ higher than the plain-based group, and a froghair right. Wind was very light and variable, so I doubt it had any effect on the results.
What do it mean? For one thing, I lucked into a fine shooting old Winchester. It is easily holding 1 MOA at three football fields with a scope most people would sell at a garage sale.
Either load would work fine on a 300 yard deer, with a 200 yard zero and high shoulder hold. Holding on the hair at the hump of the shoulder should produce sure-killing shots, to about 365 yards.
If you screw up your hold the least little bit, you will miss with either bullet beyond 350 yards.
If I routinely expected to shoot 350+ yards with this rifle, I’d load the boat-tail and practice with it a LOT at the longer distances.