July 10, 2006
The Facts About Bedding a Rifle Barrel
By David E. Petzal and Phil Bourjaily
A while back the subject of bedding a barrel came up, and was shunted aside for something more glamorous. But it’s important, and here’s some stuff worth knowing:
When a rifle is fired, its barrel twangs; I’m told by an engineer who has studied the subject that if you could watch it in slow motion, the tube would appear to appear to shimmy like a snake (waddle like a duck; that’s the way you do when you do the huckle buck).
Anyway, the purpose of bedding the barrel is to make sure the damn thing shimmies exactly the same way for every shot. The easiest way to bed a barrel is not to bed it—free-float the sucker from where the chamber swell tapers down right out to the end. Then let it do whatever it wants. Most factory rifles are made this way because it’s cheap and usually works very well.
Melvin Forbes of New Ultra Light Arms beds his fore-ends so they just touch the barrel. There’s no pressure, but there is a dampening effect. Melvin is able to do this because his Kevlar-graphite stocks are as rigid as I-beams, and once they’re bedded they stay put forever.
Top-line custom gunmakers who work in wood have long believed in full-length bedding (you need good, dry wood and a lot of skill to do this), and some of them like to shape the fore-end so it puts upward pressure on the barrel, although there are people who will tell you that wood being what it is, there’s no real way to achieve this.
Reinhart Fajen, the stockmaking company of yore, used a variation on this system. They’d free float the barrel except for two little bumps that sat 45 degrees apart about 2 inches back from the fore-end tip. This system was supposedly immune to the problems of full-length bedding, but had the same overall effect.