Boyd Allen
Active member
In California we are blessed with the need to convert to lead free bullets. Some that my friends have tried have not shown good accuracy or terminal performance on ground squirrels. Due to their being less dense, they are longer for a given weight, which may require a tighter rifling twist. Recently I tried some of the 40 grain Nosler BTLFs (Ballistic tip lead free) in my 12" twist .22-250 and was pleased with their accuracy, but I have been told they are too long for the 14" twist barrel that I have in my .222s. I knew that they make a 35 gr. version of the same bullet, but I was just sure that the BC would be under .200. It turns out that I was wrong. It is .201, not great, but usable given that with the light weight will come added velocity. The question was how much.
Today I took a .222 bench rifle to the range to find out what the top velocity is that I can get with the 35 grain bullets, propelled by LT30. The rifle has a heavy, Hart, 14" twist barrel, that is 22 inches long. The chamber is snug in the body, with a .244 neck, zero freebore, and a degree and a half per side leade angle. I seated the bullets about .006 into the rifling, and started out at the book maximum load, that I knew to be very conservative, based on experience with another caliber, using the same powder. Even so, with 19.5 grains of LT30 the book velocity, at slightly less than 50K PSI is over 3,600 FPS (Western Powder data). I worked up in half grain steps, playing close attention to primers, and bolt lift. I had a long way to go. When I saw a primer with some darkening at its edges, I stopped, backed up to the previous load (which had required a slow drop from the measure to make room for the bullet) and ran it over the chronograph. The velocity was 3,863, the bolt lift normal, and there was no primer leakage. Later deprimed the case that had shown some primer leakage first, by hand and reprimed it to see if the pocket had loosened, It had not. The temperature was around 66 degrees, a beautiful day.
The other purpose for my trip was to be the first person to shoot from a new prototype bench that I had designed, and another club member had been kind enough to build for the range. It is the first of a set that will replace the shaky old wood benches. The new bench is amazingly rigid, and gave up nothing to the concrete ones that I have a lot of experience with. To say the least, I am very pleased. Its frame is made from 4" square, 2x4, and 2x2 eighth wall tube, welded, with the legs connected about 8" off of the floor with 4" sq. and 2X4 tubing. I had been pretty sure that the design would be a good one, but one never really knows until he ties it. It passed with flying colors.
Today I took a .222 bench rifle to the range to find out what the top velocity is that I can get with the 35 grain bullets, propelled by LT30. The rifle has a heavy, Hart, 14" twist barrel, that is 22 inches long. The chamber is snug in the body, with a .244 neck, zero freebore, and a degree and a half per side leade angle. I seated the bullets about .006 into the rifling, and started out at the book maximum load, that I knew to be very conservative, based on experience with another caliber, using the same powder. Even so, with 19.5 grains of LT30 the book velocity, at slightly less than 50K PSI is over 3,600 FPS (Western Powder data). I worked up in half grain steps, playing close attention to primers, and bolt lift. I had a long way to go. When I saw a primer with some darkening at its edges, I stopped, backed up to the previous load (which had required a slow drop from the measure to make room for the bullet) and ran it over the chronograph. The velocity was 3,863, the bolt lift normal, and there was no primer leakage. Later deprimed the case that had shown some primer leakage first, by hand and reprimed it to see if the pocket had loosened, It had not. The temperature was around 66 degrees, a beautiful day.
The other purpose for my trip was to be the first person to shoot from a new prototype bench that I had designed, and another club member had been kind enough to build for the range. It is the first of a set that will replace the shaky old wood benches. The new bench is amazingly rigid, and gave up nothing to the concrete ones that I have a lot of experience with. To say the least, I am very pleased. Its frame is made from 4" square, 2x4, and 2x2 eighth wall tube, welded, with the legs connected about 8" off of the floor with 4" sq. and 2X4 tubing. I had been pretty sure that the design would be a good one, but one never really knows until he ties it. It passed with flying colors.
concrete tops for benchrest benches.
