Savage 10ML-II: On Primers and Heat
The question comes up from time to time about the "best" or "most accurate" 209 shotshell primers to use in a Savage 10ML-II, and also how to avoid frustration in 80 degree (or warmer) range work. I'll try to briefly touch on these two areas, in the hopes it can reduce or eliminate unnecessary frustration.
The Savage 10ML-II is unique in that the 209 shotshell primer is carried into and out from the breechplug via the patented, half moon primer holder that is integrated into the bolt. No primer cannot stick inside the breechplug as they can in other muzzleloaders, nor are plastic primer holders, decappers, or red plastic thingys required.
If you have reloaded over the years, you are likely aware that 209 shotshell primers vary in dimension by manufacturer. This shouldn't be surprising, as battery cup anvil primers were never designed for loose fit or slip fit use at all-- they are designed to be press fit flush into the bottom of a shotshell hull. Respective manufacturer's primers are designed to fit their own hulls: Remington STS primers fit well into their "STS" or "Nitro 27" hulls, Winchester 209s take a little more leverage on my MEC 9000G presses to seat. Federal 209A hulls are larger yet, best suited to Federal's Reifenhauser style hulls.
The hierarchy of primer size runs from Remington having the smallest outside diameter, then Winchester 209s, with Federal 209A primers as the largest. All are considered "magnum strength primers," but Federals are the hottest, then Winchester, with Remington STS primers as the weakest of the three. All are very consistent in size from lot to lot. I have little experience with Fiocchi, Cheddite, or CCI 209 primers in reloading or muzzleloader use-- so I won't comment on them.
Winchester 209 primers tend to fit most Savage 10ML-II breechplugs the best and are also perhaps the most readily available shotshell primers. That's what most Savage shooters are using, and most inline muzzleloaders for that matter. I avoid Remington primers in muzzleloaders, as they have given me several misfires-- where Winchester and Federal primers have not. Savage Arms has long recommended Winchester 209s, and they are universally the best choice. I prefer Federal 209A primers in all my frontloaders, as the hottest, most reliable ignition is what I want. Federals will also give you a slight velocity increase in the 10ML-II application, 20 - 25 fps depending on charge type and amount, but they may make your bolt hard to close. Using Winchesters is the fix; some have lightly reamed out the primer pocket to better accommodate Federals. I have detected no accuracy difference, regardless of primer used, in any muzzleloader. Winchester W209 remains the most available and generally most suitable primer with Savage recommended powders in the Savage 10ML-II.
HEAT
This is the time of the year, late summer, when many folks are breaking out their Savage 10ML-II's for the first time, for sighting-in and practice. It is still quite warm in many places including right here in northern Illinois-and heat is the enemy of the sabots we rely upon.
Heat quickly softens and weakens sabots. Today's latest MMP sabots are vastly superior to anything available just a few years ago, but they are still soft and will always need to be-pliable enough that they can be smoothly loaded from the muzzle. Hold a cigarette lighter beneath a sabot: you will see the petals quickly wilt, melt, and catch fire. The sabot will continue to burn. Please extinguish and dispose of properly. That little test is with no induced barrel pressure, and cannot compare with the blast of 5000 degree + heat and pressure we give it when firing it. The Savage 10ML-II is so very easy to operate, with exceedingly clean burning propellants and no swabbing between shots required-so, it isn't hard to see how barrel heating can quickly become a sabot damaging issue. As we need not clean, spit patch, or introduce any solvents into the barrel at all during a range session--reasonable care must be taken to keep our barrels cool if we want accurate, confidence-inspiring results.
On hot days, if we can feel heat from the barrel (the hottest area will be by the rear ramp sight) our barrel is too hot. We may need to allow 10 to 15 minutes between shots, never loading powder or sabot until right before we fire for best accuracy. Certainly this is no hunting issue, but it is a range issue in 80 degree and hotter weather.
There is more we can do, to cut the barrel heating down dramatically and reduce the barrel cooling time required down in concert. That is comprised of two things: use 250 grain bullets instead of 300 gr. bullets, and drop that powder charge down. Less powder burn, less pressure, and markedly less heat is the result.
Specifically, use 38 grains of Vihtavouri N110 or 40 grains of Accurate Arms 5744 pushing a .452 Hornady XTP in the short black MMP sabot or a 250 gr. Barnes MZ-Expander with its supplied MMP HPH-12 sabot. You will enjoy the lack of recoil, and barrel heating will be reduced dramatically.
Don't be fooled by the pleasant, soft-shooting loads, though. That 38 grains of N110 is good for about 2150 fps, for example. The 40 grains of Accurate Arms 5744 approximates the Lee 3.1cc plastic dipper scooped load. Either load will allow you (sighted in 3 inches high) to aim straight through the body of a whitetail out to about 185 yards, and will ruin the day of most any game animal in North America quite proficiently. They are great hunting loads for most any year-round conditions. Just because you have a gun that is supremely lethal on one end but a delight to shoot is no reason to feel guilty!
Have fun,
Randy
© August, 2005 by Randy Wakeman
