So I have some new brass on the way, along with some 7828, and some 162 Amax to play with in the STW. I'm still set on making the 160 AB shoot, as I want to use that bullet for game (mostly elk). I had tried some H1000 a while ago and it showed some real promise. It was doing the two and one deal, but not really bad. So I shortened them .020" of an inch to 3.605" and broke my loads down to .5 gr increments instead of 1 gr. The velocity was not what I was hoping for out of an STW, but I'm getting tired of trying to get both scroching speed, and sub .5 MOA groups.
I started at 79.5 gr of H1000 and got this group. Average speed was 3144. I was still getting extractor marks on the back of my case, but I honestly can't think of a load that I didn't (more on that later). Here is the group. Up to this point this was the best 160 AB group I have got this rifle to give me.
View attachment 2012-08-16_06-56-44_938.jpg
Next up was 80 gr. Same thing, 3159 fps, and same extractor marks. Not sticky bolt lift or anything. This load did not get as much of a chance to cool as I would have liked between shots. I was getting to be late for work, and had to get going. But as you can see, it shot even better that the last group (ok, about the same really)
View attachment 2012-08-16_08-24-23_807.jpg
So my questions for you guys that know more than me (pretty much all of you) are the following.
1. What could be causing such excess pressure in my gun? Another guy I know is shooting 80.5 gr of H1000, getting 3250, and no pressure. A different guy I know is getting almost 3300 with the 160 AB. Both of these guys are shooting factory STWs. I can get 3250 with Retumbo, but its not near as accurate, and appears to be just as hot pressure wise.
Could it be that my smiths reamer has tighter tolerences that a factory reamer?
Could the difference be the three groove barrel over the factory?
Could my chamber be dirty? (I clean it every time I clean my barrel)
Any other thoughts?
Do I need to look at an even slower powder that Retumbo or H1000 to get the speed one should expect from a STW?
Overall, I'm happy with these groups. I'll take this kind of a groups over an extra 100 fps anyday, (unless its a 270 WSM, in that case I won't be happy until I turn it into a 270 Weatherby :roll: )
If you see this with no pics, they are on the way. They are on my phone, I'll add them in a few. If I tried to type this on my phone you guys wouldn't see it for another month :?
I started at 79.5 gr of H1000 and got this group. Average speed was 3144. I was still getting extractor marks on the back of my case, but I honestly can't think of a load that I didn't (more on that later). Here is the group. Up to this point this was the best 160 AB group I have got this rifle to give me.
View attachment 2012-08-16_06-56-44_938.jpg
Next up was 80 gr. Same thing, 3159 fps, and same extractor marks. Not sticky bolt lift or anything. This load did not get as much of a chance to cool as I would have liked between shots. I was getting to be late for work, and had to get going. But as you can see, it shot even better that the last group (ok, about the same really)
View attachment 2012-08-16_08-24-23_807.jpg
So my questions for you guys that know more than me (pretty much all of you) are the following.
1. What could be causing such excess pressure in my gun? Another guy I know is shooting 80.5 gr of H1000, getting 3250, and no pressure. A different guy I know is getting almost 3300 with the 160 AB. Both of these guys are shooting factory STWs. I can get 3250 with Retumbo, but its not near as accurate, and appears to be just as hot pressure wise.
Could it be that my smiths reamer has tighter tolerences that a factory reamer?
Could the difference be the three groove barrel over the factory?
Could my chamber be dirty? (I clean it every time I clean my barrel)
Any other thoughts?
Do I need to look at an even slower powder that Retumbo or H1000 to get the speed one should expect from a STW?
Overall, I'm happy with these groups. I'll take this kind of a groups over an extra 100 fps anyday, (unless its a 270 WSM, in that case I won't be happy until I turn it into a 270 Weatherby :roll: )
If you see this with no pics, they are on the way. They are on my phone, I'll add them in a few. If I tried to type this on my phone you guys wouldn't see it for another month :?