The Return of 1895 Chucky Part I

The Model 1895 Guide Gun is light, fast tracking and accurate. I can load it down for deer and hogs and load it up for the biggest and most fierce North American game. There is relatively flat shooting ammunition and component bullets for handloaders as illustrated on the preceding table. There are heavy cast loads that can traverse a cape buffalo and hole punch a brown bear or moose. Throughout this range of capability, the rifle remains the same; compact, easy to haul around the woods and solidly reliable.

If this Guide Gun version gives away anything, it would be a bit of velocity in comparison to the 22″ and 24″ barrel models. The loss tends to be less with heavier bullets than light and is influenced by powder types in addition to bullet weight.

Duality Vs Play Doh’s dualism… Wut?

There are modern firearms chambered for the 45-70 Gov’t and none of them, by public statement, support ammunition manufactured with a +P or Magnum designation. They do not warrant the use of this ammunition as there is no SAAMI or CIP +P or Magnum designated standard. Those designations are under the control of the manufacturer of the ammunition and applied at their discretion with two companies applying the exact same pressure criteria. To mitigate their differences, firearm manufacturers leave it up to the ammunition manufacturers to specify which firearms can handle their respective ammunition.

The degree of difference between SAAMI standard ammunition and modern high pressure ammunition is not insignificant. The SAAMI pressure rating for the 45-70 Gov’t is 28,000 psi. Garrett states a limit of  35,000 PSI while acknowledging that other manufacturers see up to 43,000 psi as a safe level for the Marlin Model 1895. Buffalo Bore does not publish a reference pressure, but by my calculation it takes approximately 39,000 PSI to drive a 430 lead cast bullet to 1879 fps from an 18.5″ barrel. Loading with transducer or strain gauge equipment checks, I generally maintain a max of 39,000 psi for Marlin Guide Gun use and close to 50,000 psi with shop Ruger No.1 rifles. Loading for the Marlin using Ruger No.1 pressure levels will permanently damage a Marlin and cause dangerous failures.

So why not create a SAAMI 45-70 +P standard as there is for cartridges like the 9mm Luger, 45 Auto and 45 Colt so firearm manufacturers can authorize use of a known quantity? Beats me. Perhaps firearm manufacturers don’t want to extend product liability or perhaps the system works the way it is and everyone is happy.

So where does this lead, lead and leave us?

Collecting baseline data for factory ammunition offers some insight into performance expectations for the 18.5″ barrel gun, places it in context with longer barrel models and provides points of comparison for coming handloads. Factory test barrels for the 45-70, used to rate ammunition, are 24″ long.