- September 5, 2017 at 12:27 pm #46936GoodsteelKeymaster
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There is a lot of misconception about this, and I’ve personally fired the first shots in so many rifles I have lost count, so I’d like to give the benefit of my experiences to the membership here. Take it for what it’s worth, but I’m coming at this from a business standpoint. It is rare for me to take a rifle and shoot it to see how well it will do. I’m strictly looking for failure or weaknesses in the build or the new rifle, and the gun must win my approval or we are going back to the bench for a serious heart to heart discussion about how the rifle can quit sucking wind. In this way, I’m a completely heartless bastard because I’ll call BS on a rifle’s precision so fast it’ll make your head spin. This might seem backward to you, but it’s not really when you think about it.
So, lets say I just bought a Savage Model 10 FCP-SR in 308 with a 1-10 twist barrel 24″ long.
The first thing I’m going to do is select a bullet. I know from experience that the 178 Amax and the 180SMK are excellent, consistent performers in this rifle, and in that twist rate, so that’s what I will go with. True I could have selected a Berger Hybrid, or a 168 Amax or SMK, but the 178 is in the middle. It’s balanced.
So then I flip open my reloading books. Lyman 45th, the latest Sierra manual, and a book I have printed by reloading magazine that has dam near everything except black powder for every load. I also open Hodgdon’s online website.
I peruse the data for the 175-180 grain bullets and compare between the manuals, and take reasonable note of the stated accuracy loads (if given) to see if there is any trend towards the fast or slow powders (this is absolutely unnecessary for 308 as many of the powders were designed for that case capacity/bullet weight and the burn rate is idealy suited to a cartridge like that) . I always select a powder that is in the middle of the burn rate (they are typically listed by burn rate) for a middle weight bullet. I err on the slow side for heavier bullets, and the fast side for lighter bullets. I select the charge weight as the upper 1/4 of the available range from minimum to maximum. So say the charge weight for the powder I use is 39.5-44.5 grains, I will throw a charge of 43.7 grains. I throw the charges by volume. I do not trickle every charge. There is absolutely no need until the exact load is known.
Then I assemble the ammo. Not much care is given to the seating depth as a broad range of seating depths will produce excellent results. I typically measure with the Hornady OAL gauge and hold back .005 from touching the lands. I am not very particular with brass except that I expect it to dunk into a chamber gauge perfectly, be of all the same headstamp, and be trimmed to exactly the same length. I am not particular with primers.
The seating die is set up by screwing it down till it touches the mouth of an empty piece of brass, then backed off 1/4 turn. The seating stem is backed all the way off, a bullet set on a charged piece of brass, and pushed into the die. I screw the stem down till it touches the bullet, drop the ram a little, screw the stem down, seat the bullet, measure, adjust, seat, repeat till the exact seating depth is achieved. Then I back off the seating stem again, and screw the die body down till it touches the case mouth. I raise and lower the ram as a screw the die in feeling for that perfect crimp. Once the crimp is set, I tighten the lock nut on the die, then screw the stem down till it touches the bullet and lock it in place hard.
That first piece of ammunition is checked with a chamber gauge, and every subsequent cartridge is as well. I make at least 20 pieces.
Next I go to the bench with the rifle and prepare to shoot. I always run a good number of patches through the barrel before starting. I bore sight the scope, then fire one shot into the berm. Then shoot the next one into the target. I adjust the knobs on the scope to the point of impact, then shoot 6 into that point of impact. I expect to see vertical stringing with these first ten shots with an impact point that works it’s way down the target as the bullets leave the barrel faster and faster (yes, faster bullets impact lower at 100 yards).
Once that is done, I am left with 12 shots and a hot barrel. I take the rifle in the shop and push patches through till they come out clean.
Back on the bench, I shoot two into the berm right quick, then pick an aim point and shoot once more. That is the first shot of the ten shot group. I set a timer for 1 minute and leave the action open while that minute passes. I load another cartridge, shoot, then set the 1 minute timer again.
The ten shot group produced is telling. If it’s about 2″, then we need a setback, or a new barrel, but most of the time that shot will be close to 1″ with a factory barrel (this is a NEW rifle remember, and American rifle makers have really improved here in the past 10 years over the garbage they were often putting out in the 70s, 80’s and 90’s.
This is the same process I use for my new rifle builds. Every MBT rifle has been fired at least 20 times and thoroughly cleaned between strings.
Using the method above, I feel confident that the results are trustworthy for a rough demonstration of a random rifle’s abilities.
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