Government Profile Vs. Pencil Barrel

The other day, Herschel at The Captain’s Journal had a blog post regarding the government profile barrel for the AR-15 and the M16A2. He made the point that the government profile barrel was adopted based upon erroneous assumptions and without proper engineering failure tests. He also said that top end AR makers continuing to put out rifles with government profile barrels was dumb.

First, I question their testing of the resistance to bending of a “government profile” barrel. They obviously never got real engineers involved in this problem. The highest bending moment in a cantilever beam will be where it is pinned, which in this case will be at the receiver. As best as I can tell, not only didn’t they solve a real problem, they didn’t even solve the pretend problem.

Second, engineering resources would have performed a failure mode and effects analysis of the problem. A failure investigation team of engineers should have been commissioned, not a military team.

Third, if you believe the problem is that Soldiers or Marines are using their rifles to pry open boxes or crates, then teach them not to do that. That’s stupid. I remain unimpressed with folks who try to mistreat, abuse and beat up their guns only to complain when they don’t work.

It was an interesting post with good comments. You should read the whole thing.

That led to me finding this video from last year by Ian and Karl from InRangeTV and their WWSD (What Would Stoner Do) series. In it, they test stress relieved pencil barrels from Faxon and then compare that to an original pencil-barreled Colt SP-1 doing the same test. Given I have one of those Faxon pencil barrels, I need to get my act together and finish my lightweight build using it!

PS: Lest you think I’ve gone all “what has Wayne done now” all the time, being able to have a day without significant charges of malfeasance and self-dealing is a relief. However, the day is still young.

“The TSA: Or How To Feel Unwelcome In Your Own Country”

Karl Kasarda, who along with Ian McCollum, produces InRange TV had an “interesting” experience with the Travel Security Administration on a recent trip. He had been selected for special security screening on a trip home from Scandanavia. He was screened twice – once in Stockholm and once in Chicago. You can guess in which screening he was treated with respect and courtesy. I’ll let him finish the story.

I think I’ve made my feelings about TSA known over the years so I’ll just leave it at that.

WWSD: The Charging Handle

The charging handle seems, on the surface, to be one of those parts of an AR15 that doesn’t matter that much. You can spend a lot more on a charging handle but the $12 aluminum mil-spec charging handle will work just fine most of the time. By comparison, a gritty mil-spec trigger has the potential – and some would say the probability – to impact your accuracy with the rifle.

I will admit to not having given it too much thought. I have a couple of blem BCM charging handles and just ordered a Radians Raptor charging handle because I got a good deal on it. Then this morning I watched the video below by Ian McCollum and Karl Kasarda of InRange TV about their What Would Stoner Do project.

They have given it much more thought than I had and brought up points I hadn’t considered about charging handles. I very well may consider the Geissele the next time I find them on sale. Given I use their triggers perhaps I should also be using their charging handle on some of my ARs.

Interesting Test Of Pencil Barrels

The original M16/AR-15 from Colt was produced with a pencil barrel. Later iterations of the rifle and carbine had a heavier and thicker barrel because it was found that the pencil barrel would flex when it got hot. The barrel flexing resulted in a change in the point of impact. The practical effect of this barrel flexing for the military was that shots ostensibly on target were missing the enemy at longer ranges.

You can see the difference in thickness between a pencil barrel and a “government” profile barrel in the pictures below. Both of these barrels (and the pictures of them) are from Faxon Firearms.

Faxon 16″ pencil barrel

Faxon 16″ M4 government profile barrel

Ian and Karl at InRange TV are doing a series called “What Would Stoner Do”. The latest in their WWSD series tests the effect that heat can have on pencil barrels and the point of impact. They tested both a modern Faxon barrel and an original Colt SP1 barrel. Faxon claims that their proprietary method of building in stress reliefs mitigates the significant change in point of impact caused by heat. Part of Ian and Karl’s reasoning behind testing pencil barrels is that a pencil barrel is a quick way to reduce the weight of the rifle.

I found this highly interesting as I am in the process of assembling parts to make a lightweight AR using this same Faxon pencil barrel. I got a great deal on one at the recent NRA Annual Meeting and decided that I “needed” another AR. I am also in the process of putting together a retro styled clone of the M16A1 using a mix of original and modern parts. This latter rifle uses a 20″ barrel from Green Mountain Rifle Barrels which has the original 1 in 12″ twist. My dad qualified Expert with such a rifle back in the 1960s and the build is partly meant to honor him.