Even though several bullet companies made 75 grain varmint bullets in this bore size, and even though I had obtained good results with these in other .25 cal. rifles, I did only very limited testing with the Hornady Spire Point in this weight, chosing to concentrate on bullets of 85 grain weight. The Nosler Ballistic Tip was a brand new item at this time, and I decided to see what all the hoopla was about. In a word, the hoopla was right! (Note, even though the .25 cal 85 gr. Ballistic Tip is a varmint bullet, the 85-gr Ballistic Silver tip made by Combined Technologies [Nosler and Winchester] is a hunting bullet.)
Using seven different powders, varying from IMR 4895 through Accurate MR-8700, this bullet proved to be the most accurate one tried in this rifle. Of 38 four-shot groups, exactly one was over an inch, and eight were smaller than 1/2" at 100 yards. The most consistently small groups were produced by 59.0 grains of the old surplus H-4831, which gave 3540 fps from the Ruger’s 24" barrel. Other very small average groups were fired with 47.5 gr. IMR 4895 (3530 fps), and 59.0 gr. of the newly-manufactured H-4831 (3529 fps). Before we go any further, and as you will see when we discuss the next rifle, BE CAREFUL! Loads which were close to maximum in this gun – as was the aforementioned Old H-4831 load – may be totally unsafe in another .25-06-chambered rifle. This is especially true if your gun has a custom chamber, or if it was made before this cartridge became a standardized factory round. Start at least three to five grains below any load listed herein, and work up carefully in 1/2-grain increments. Neither PS, nor Editor Dave, nor the author, nor our heirs executors, administrators, assigns, nor even our dogs, cats or hedgehogs can be responsible for your failure to adhere to this caution.
More out of pure curiosity than from any thought of ever using this particular rifle as a game gun, I also tried some loads with the 100 gr. Speer spitzer and 120 gr. Remington Pointed CoreLokt. Accuracy with the former was, for the most part, pretty good, while the 120 Rem. was a bit less consistent, but still produced a few groups of less than one inch. Velocity with the Speer approached 3350 fps, and with the heavier bullet would occasionally reach 3200 fps. In a lighter rifle, either of these bullet weights would be perfectly acceptable for hunting animals at least the size of any white tail or mule deer around.
Ruger M-77 Mk II VT, with 6-20x Leupold scope. Although originally chambered for the standard .25-06, it is now a .25-06 Ackley Improved.
The theory that what you can learn from one gun in any given chambering can better be learned from two guns has always served me well. It makes for a marvelous excuse to buy a second such gun. Likewise, the temptation to try practically any given round not only in its original form, but also in its Ackley Improved configuration has always been an influencing factor in my gun buying endeavors. So these thoughts were first and foremost in my mind when I spied a brand new Ruger M-77 Mark II Varmint-Target with a long action in a local store. Knowing that the .25-06 is the only chambering offered in a long-action VT, and needing such a platform to build up a .25-06 Ackley, it didn’t take long for me to part with some of my hard-earned dollars. I also made the unusually good decision to “sort it out” a bit in its original chambering, before parting with even more of my hard-earned bucks. This would also permit me to compare “apples to apples” after re-chambering.
The Mark II version of the Ruger bolt-action rifle isn’t too different from the original (the safety is changed, as are the ejector, the trigger and the floor plate release), but one particular in which it is vastly different is in the barrel. S R & Co. completed the change-over from the M-77 to the MK II about the same time as they purchased all new hammer-forged barrel-making equipment. (The rumor then was they had acquired the machinery from Steyr, but I haven’t confirmed that.) In any event, prior to purchasing the Mk II in .25-06, my only experience with one of their new barrels had been with one of the very first blued receiver Varmint versions of the Mark II chambered in .220 Swift. (The .25-06 Mk II is all stainless.) The Swift had performed very well, so I had no doubts about the barrel on this new rifle.
Starting with the 85 grain Nosler Ballistic Tip which had shot so well in my older .25-06, I was a bit disappointed with the accuracy, but certainly not with the velocity obtained with this two inch longer barrel. The new gun also seemed willing to digest somewhat increased powder charges without any obvious signs of too-high pressure. An additional 100 fps or so was obtained by this combination of longer barrel and increased powder charge. I was hoping that the mediocre accuracy might have been due to the barrel not being fully in broken yet. Also about this time I had become acquainted with Jef and Ed Fowler’s excellent match bullets and learned that they were making flat-based 85 grain .25 cal bullets. I still don’t know if it was pure coincidence or the barrel breaking in, but the Fowler bullet shot well right off the bat. In fact, the second load tried – 58.5 grains of Accurate’s short-lived MRP – gave mild velocity (3474 fps) but very acceptable 1/2" groups. These bullets, unfortunately, are no longer in production, due to Jef Fowler’s untimely death. (Editor: applies to .257 caliber only.)
The bullets tested by the author in his latest incarnation of the .25-06 Improved. From left: 75-grain Sierra hollow point, 75 Hornady V-Max, 85 Nosler Ballistic Tip, 85 Fowler hollow point, and 85 Starke Red Prairie.
Not all powders were as good and accuracy was not quite as consistent as with my older Ruger, but enough 1/2" groups showed up on the paper to convince me this gun was definitely a keeper. Although I did not try some of the faster-burning powders I had previously used, like the 4895s and IMR 4064, any powders similar in burning rate to the various 4350s or 4831s worked just fine. Highest velocity was obtained with IMR 4831 (3771 fps). In fact, I had to almost force myself to quit shooting the gun as it was and re-chamber it before too much barrel life was used up!
Off to Carl Chiocca it went for re-chambering. Although he accused me of mellowing in my old age (A: the job was simpler than usual; B: the cartridge was not as weird as my usual concoctions and C: this was one of those blankety-blank small bores), he still did his usual excellent job of chambering, after cutting a couple threads off the barrel shank and setting it back. Now I was ready to see whether the “Ackley Fire Formed Improved” chamber would actually offer much of an improvement over not only a standard chamber, but in particular over a chamber that was not all that tapered or slope-shouldered to begin with; no huge “improvement” in case shape would take place.
Even though I hate to disappoint those loyal readers who are, no doubt, hanging on my every word, and anxiously awaiting every small detail of this rifle and the results of my re-chambering, I must state that this particular gun and chambering has already appeared in print (TAR, April, 2004). This being so, I will just hit the high points at this time.