Ruger's PC Carbine Part II

I am having a heck of time reviewing the Ruger PC Carbine. Sub zero weather, snow storms and an errant HTML table edit that credited the little rifle with Martian origins, an alphabetically nomenclature trigger and a trigger guard fabricated from exotic aircraft aluminum. The cause could have been old age, could be extreme cold, could be my learning curve, or even site editing software that no longer reflects the tools of twenty prior years of writing. I don’t know, but I do know that some folks will find and fixate on an obvious typo even after correction, and skip the substance of the other thousand words and pictures, then entertain themselves by continuously shouting “There is a booger on your nose”. Third grade is never far enough behind us.

Reshoot… just like Hollywood

When last we spoke of the Ruger PC Carbine, ammunition velocity was compared; factory rated, 4.25″ barrel chronograph data and the Ruger PC Carbine data. Unfortunately, it is winter in Maine so the latter was shot in a not frost free freezer with temps below zero, then compared to 4.25″ barrel data that was shot at 65°F. Not much of a controlled comparison. Subsequently, a jet heater was cranked up to move the enclosed shooting bench and chronograph area closer to the equator, where all was warmed to a balmy 65°F. The Ruger PC Carbine factory ammo segment was re-shot and then used to used to draw short barrel – long barrel velocity comparisons. An infrared thermometer was used to verify… the new one my wife got me for Christmas. Thanks, Sweetie.

Joe, thanks for the data, but what does this all mean? Who knows? All I know is that I was warm for a change and three rounds of each were shot over the chronograph to flush out any anomalies so they could be appropriately dealt with. In general, the long barrel adds meaningful velocity to the 9mm Luger, with one exception… where it is a good thing when it comes to subsonic flight. Increasing ambient temperature and allowing ammunition, firearm and chronograph to come along for the ride generally increases velocity, but not always.

My guess is that the subsonic loss of fps is related to long bullet shanks, reduced charges and increased bore friction when compared to a 4.25″ pistol. My guess, regarding drops in velocity in a warmed environment, are related to the chemical characteristics of the powder. Does this matter? Probably not as there are 115 popular factory loads for the 9mm Luger and no way of predicting what people will shoot or if a shooter is operating in Florida or under Maine’s own brand of sunshine. In fact we are expecting 12″ – 18″ of Maine sunshine tomorrow and gale winds to make it all more interesting. Perhaps penetration in a snow bank or frozen gel blocks would be a useful indices?

If you don’t handload, you’re just a ballistic bean counter…

Within the confines, context or other words of boundaries describing Part I, factory ammo was dutifully shot, each cartridge’s performance was noted and we all went home enjoying the PC Carbine’s fault free  performance. The thing is, I actually enjoyed shooting the little rifle and I got to wondering about its greater potential. I do like to develop handloads, so that seemed a plausible excuse for shooting the carbine some more. Subsequently, multiples of six bullet types I shoot frequently were selected, then one was deselected.

As they appear left to right above… except as noted:

The Nosler Sporting Handgun 115 grain is a short shank bullet that it resistant to expansion at pistol velocities. The theory was that a long barrel bump in velocity would finally make this stash of bullet useful for purposes other than paper punching.

The Remington Golden Saber, or whatever name it goes by these days, with a groove diameter driving band at the heel and a bore diameter shank, is a bit of a bore glider. I theorized this would play to the carbine’s longer than pistol length barrel.

The Hunter’s Supply 125 grain hard cast is another short shank bullet with minimal bearing surface thanks to its crimp groove and driving bands. For theories, please see previous. I like shooting hard cast as they perform like crazy, they are relatively inexpensive and the bore clean up is minimal.

The 147 grain Speer Gold Dot, far right, has a straight shank and is not recommended by Speer for barrels longer than 10″ where a relatively large bearing surface and high bore friction meet a relatively small powder charges.The Speer reloading manual addresses handloading for rifles chambered for handgun cartridges, giving special attention to the 9mm Luger within those applications. The concern expressed is that minimal charges and heavy bullets may result in bore stuck bullets. Yes, it is in the manual. You just have to take the manual from under your work bench’s short leg and read it.

Pictured above, to the left of the Speer bullet is a Remington 147 grain bullet. In 1999, Remington domed the bullet’s heel so they could shorten the bullet shank so it would not encounter the case’s internal tapered web and bulge the case. The 147 grain Hornady, even farther left of the Remington bullet, accomplishes the same by putting a taper on its heel. The approaches to avoid web contact also reduces the bullets’ bearing surface and makes them candidates for the 16.12″ carbine barrel. How so? Next slide please…

The 9mm Luger bore diameter is 0.346″, the groove diameter is 0.355. Measuring the length of each bullet’s groove diameter bearing surface, the Speer bullet length is 0.376″. The Remington and Hornady bullets measure, respectively 0.322″. 0.319″. In that order, the bearing surfaces areas are 0.620 sq.in., 0.559 sq.in. and 0.556 sq.in. or approximately a 10% less bearing surface than the Speer bullet. Would a 147 grain Remington Golden Saber work particularly well in this application? You bet. Why did I not use them at 147 grains? I ran out a week ago and reinforcements have not as yet arrived.

Subsonic. My ears are quite fond of subsonic rounds. They are enjoyable to shoot, the rounds, not my ears, for recreational target work; nice to hear the target clanging and bolt cycling clacking through the diminish report. Typically I shoot the heaviest, most streamlined bullet possible for subsonic cartridges. Since the bullet velocity will be inhibited anyway, it is reasonable to shoot the heaviest bullets possible as they will retain velocity and energy longer, and penetrate deeper on impact. In this instance,a couple of 147 grain bullets were naturals for subsonic and the quietest of all handloads with a silencer in place. I did add a 124 grain hard cast subsonic load which was also quite quiet.

No problems were experienced with subsonic loads in terms of cycling or clearing the barrel. I am a relatively conservative handloader, always working toward a long and uneventful handloading future. It would be nice to leave readers with the impression that the Ruger PC Carbine owes its accurate results to my pretty terrific handloads… but I can’t. Truth be told, most factory ammo delivered similar accuracy.

Observations…

Standard 9mm Luger SAAMI pressure is 35,000 PSI, the +P version is 38,500 PSI. The issue to deal with was mostly case capacity and powder density. +P pressure  was easier to attain with moderate speed powder, as slow powder filled a case before higher pressure could be reached without resorting to seriously compressed charge loads. There were no flattened primers and no bulged cases symptomatic of early breech opening. COL is important as relatively minor variation on bullet seating has a significant effect on pressure.

Sandbagged and scoped…

I probably should have left the heat on while I shot these groups; shivering and teeth chattering aren’t conducive to a steady sight picture and I did go through a good deal of ammo on the way to the table and pictures. Just for drill, the barrel was pulled and reinstalled and the bolt was allowed to  slam shut on an empty chamber before loading ammo into the carbine. Within a group size I could not see a consistent, measurable shift in point of impact. This has been my experience with virtually every takedown firearm Ruger has or does produce.

For me, the Ruger PC Carbine has no recoil so, with the exception of gusting winds and subzero temperatures, there is little distraction from sight pictures. The PC Carbine is balanced, comfortable in hold and, with a silencer and subsonic rounds, it is just fun and inexpensive to shoot. With a lot more power than a rimfire camp rifle, and easier to shoot accurately than a 9mm Luger chambered pistol, it is still compact enough to walk trails with or take on a fishing excursion in some of the more remote areas in New England… like my backyard and the boonies beyond.

The Ruger PC Carbine is a good choice for home defense for folks who don’t feel comfortable when armed with a handgun. Certainly lighter and faster than a typical AR and a lot more discriminant than a shotgun in selecting targets in a close in environment. I think it is a terrific little rifle that will also see lots of use for recreational target shooting, or training new shooters without scaring them away from firearms with excessive recoil or report. I will renew my request for a 10mm Automatic version, which would greatly broaden the little carbine’s applications.

Note to Ruger: My apologies for the Part I HTML table cut and paste remnants. I know you guys put a great deal of effort into new products for firearm enthusiasts. While products are always subject to a fair assessment, plus or minus, manufacturers deserve better than sloppy handling in production from us.