September 23, 2010
Although it shoots much better than it did before bedding, the test rifle still looks the same.
Like many rifle nuts, I fall into Colonel Townsend Whelen's "only-accurate-rifles-are-interesting" camp. Sure, an inch-and-a-half rifle is plenty accurate for big-game hunting, but sub-MOA accuracy is a must for me. Rifles that don't meet my demanding accuracy standard are usually relegated to trade fodder. However, some rifles shoot well enough that a bit of tweaking will get them shooting under an inch. Such is the case with a pretty, little .308 I bought two years ago.
That little Model 700's clean, classic lines and pretty wood caught my eye as soon as I opened the box. Its classic stock fit me like a glove and handled like a dream. It was love at first sight. Sadly, it didn't shoot quite as well as it looked. But it was close, so rather than trading it off or selling it, I decided to see if I could do something to make it shoot well enough to earn the little rifle a place in my gun safe.
Although bad barrels and defective scopes can lead to poor accuracy, this rifle shot well enough that I didn't think either was the cause of its accuracy woes. Rather than spending a bunch of money rebarreling it, I decided to see if bedding the rifle would shrink my groups.
The purpose of bedding is to achieve a perfect stock-to-metal fit that ensures there is no harmonic influence on a free-floating barrel. Perfect bedding means the receiver has to be bedded in perfect alignment with the floorplate, the magazine box must have room to float between the receiver and the floorplate, and nothing should come into contact with the stock that is not intended to touch it. In short, perfect bedding eliminates a lot of variables and greatly ups the odds of a rifle delivering tack-driving accuracy.
Although I'd never done it before, I decided to do the bedding on this rifle myself. As I usually do when I start a do-it-yourself project, I opened the Brownells catalog and perused the selection of bedding compounds and tools. A quick phone call to Brownells answered all my questions and got some of the Acraglas bedding compound headed my way.
Next, a call to a gunsmith friend got me the use of his shop and tools for long enough for me to stumble my way through the bedding process. So, with my rifle and a big box of bedding supplies in hand, I headed to his shop and dove right in to bedding my rifle.
Under the watchful eye of my buddy, I removed enough stock material from the inletted areas to make room for the bedding compound. Next, I attached two aluminum pillars to the barreled action with some oversized action screws. It is crucial that the screws are centered in the pillars and that a liberal coating of release agent is applied to the inside of the pillars. Do not get release agent on the outside of the pillars as you want them to remain firmly embedded in the stock once the bedding compound dries.
You do not have to pillar bed a rifle. In fact, many people use just bedding compound. But pillars do a better job of supporting the action and, in the case of wood-stocked rifles like my Model 700, make the whole platform more stable. Since my rifle has a wood stock and because I had access to the right tools, I chose to pillar bed my Model 700.
100-Yard Accuracy Results
|Load ||Before (in.) ||After (in.) ||Best Group (in.) |
| || .308 Win. Remington Model 700 |
|Federal 150-gr. Ballistoc Tip ||2.06 ||1.30 ||1.10 |
|Federal 165-gr. Fusion ||1.10 ||0.51 ||0.42 |
| ||2.09 ||1.44 ||1.20 |
|Hornady 165-gr. BTSP ||1.27 ||1.37 ||1.20 |
|NOTES: ||Before and After groups are the average of five, three-shot groups with each load before and after bedding.Best Group refers to the smallest group fired with each load after bedding. |
The stock was drilled out for installation of the pillars.
Once I attached the pillars to the action, I taped off the barrel channel just ahead of the recoil lug with plastic tape so the bedding compound wouldn't s
tick. Next, I taped off the outside of the stock, filled the trigger slot and pin holes with clay, and sprayed the barreled action with release agent. The clay and release agent keep the bedding from sticking to the action, and the tape keeps the stock clean. This is important, as dry bedding compound is a pain to remove.
Next, I mixed the bedding compound and applied it generously to the inside of the stock, from the tang to just forward of the recoil lug. It is important to apply enough bedding compound so it fills every nook and cranny of the stock. The excess will ooze out once you push the barreled action back into the stock, but don't worry about making a mess, that's why you taped off the stock.
Once I applied enough bedding compound, I pushed the barreled action back into the stock firmly, then taped it down to keep pressure on it. Once the action was in place, I let the bedding compound cure until it was a bit tacky--about two hours--then trimmed the excess bedding compound. With the clean-up done, I left the bedding to cure for 24 hours. The next day, I came back and removed the action from the stock. Thankfully, I applied enough release agent that the action came right out. If I hadn't, I would have been looking for a crowbar.
With the barreled action out of the stock, I removed the tape, filed away the excess bedding compound, and trimmed the pillars. I didn't make too big a mess, so it didn't take long, but I did have to work over a few spots to get the action back in. Once I got the stock clean, the action fit perfectly. It didn't drop in, but I didn't have to force it either. The fit was just about perfect.
Prior to bedding my rifle, I fired five, three-shot groups with four different loads and saved the targets. With my project complete, I was anxious to see if my handiwork made a difference, so I headed back to the range with those same four boxes of ammunition.
Because it was the most accurate "before" load, I started with Federal's 165-grain Fusion offering. My first group measured just 0.42 inch--phenomenal by anyone's standards--and the average of five groups was right at a half-inch. While none of the other loads grouped quite as well, two loads showed a decrease in average group size of more than 30 percent. The fourth load, Hornady's 165-grain BTSP, showed a small increase in group size, but the difference was so slight (0.1 inch) that the change was negligible. Nevertheless, that Hornady load and two loads that averaged over 2 inches before now shoot under 1.5 inches. Best of all, with Federal's 165-grain Fusion load, my rifle is now the tackdriver I hoped it would be when I started this project.
Considering the minimal expense and time relative to the improved accuracy, I would have to say bedding my rifle was well worth the effort. And it was easy enough that a "C" shop student like me could do it without getting any body parts permanently affixed to the stock. If you have a rifle that doesn't quite live up to your accuracy standards and you possess a modicum of mechanical ability, bed it.