I have always considered myself pretty careful when it comes to reloading and pressure. My reloading process involves lots of reading online of other manufacturers load data, advice from other people and sites like 6br, and pushing up to the pressure signs in my own rifle, backing off half a grain and working down to an accuracy node. It has always worked very well and the rifles are all very accurate.
My 6.5x47 Lapua is no exception. PacNor super match grade barrel in a blue printed Rem 700 action. I use RL15 as many say it's the go to powder along with N550. It has always preferred RL15 so I have stuck with it.
The rifle has shot a few hundred deer has been through the test process on 4 different bullets and enjoyed a few of days on the range. I estimate it has fired 700-800 rounds. It has always been loaded fairly hot, a 129 ABLR at 2910 fps and a 123 Scenar at 2980 fps are two of the loads. No pressure signs, no sticky bolts, no flat primers. Shoots in the 0.4's if I do my bit.
All good, right? As long as you stay under pressure all should be fine.
I have always measured everything, including OAL to ogive when engaging the lands. I only ever do it when I'm loading a new bullet as an initial measurement. I got a bit suspicious at the weekend that the measurement was growing so I went back to the records and checked. The data said the rifle has enjoyed 151 thou of throat erosion.
To check it I went back to the first bullet I ever loaded it with and found the lands again. Sure enough it loaded 150 thou longer than it did when the rifle was new. Looking at the interim measurements and rounds fired it's a steady, gradual increase, so not an imperfection in the original chambering that shot out very quickly.
RL15 is a double based powder. I know the spec on the website says single base, but it's not, it's a combination of Nitrocellulose and Nitroglycerine. Pressures were up over 60k psi but below the max. 63k psi, so up there but under pressure.
My cleaning regime is fairly robust. Bore Tech cleaners and nylon brushes, pushed through after every outing. On a busy day I will clean after every 30 rounds or so or the rifle goes off. I don't think it's over cleaned or cleaned too abrasively in any way. Bore guide always used.
I never fire a shot string of more that 5 and am very aware of overheating. I even give it a minute between shots on the 5 shot strings so that's really not a cause.
So...
1. Are PacNor barrels especially soft?
2. Are double based powders really that evil?
3. Should I be well below max pressures if I want to maintain a reasonable barrel life even when they advertise high max pressures?
4. Is Bore Tech particularly abrasive or corrosive?
5. Is cleaning bad?
The rifle is still shooting 1/2 minute groups, but I suspect a re barrel is close. Just trying to work out what I have done wrong so I can correct for the next one.
Thanks for the help.
My 6.5x47 Lapua is no exception. PacNor super match grade barrel in a blue printed Rem 700 action. I use RL15 as many say it's the go to powder along with N550. It has always preferred RL15 so I have stuck with it.
The rifle has shot a few hundred deer has been through the test process on 4 different bullets and enjoyed a few of days on the range. I estimate it has fired 700-800 rounds. It has always been loaded fairly hot, a 129 ABLR at 2910 fps and a 123 Scenar at 2980 fps are two of the loads. No pressure signs, no sticky bolts, no flat primers. Shoots in the 0.4's if I do my bit.
All good, right? As long as you stay under pressure all should be fine.
I have always measured everything, including OAL to ogive when engaging the lands. I only ever do it when I'm loading a new bullet as an initial measurement. I got a bit suspicious at the weekend that the measurement was growing so I went back to the records and checked. The data said the rifle has enjoyed 151 thou of throat erosion.
To check it I went back to the first bullet I ever loaded it with and found the lands again. Sure enough it loaded 150 thou longer than it did when the rifle was new. Looking at the interim measurements and rounds fired it's a steady, gradual increase, so not an imperfection in the original chambering that shot out very quickly.
RL15 is a double based powder. I know the spec on the website says single base, but it's not, it's a combination of Nitrocellulose and Nitroglycerine. Pressures were up over 60k psi but below the max. 63k psi, so up there but under pressure.
My cleaning regime is fairly robust. Bore Tech cleaners and nylon brushes, pushed through after every outing. On a busy day I will clean after every 30 rounds or so or the rifle goes off. I don't think it's over cleaned or cleaned too abrasively in any way. Bore guide always used.
I never fire a shot string of more that 5 and am very aware of overheating. I even give it a minute between shots on the 5 shot strings so that's really not a cause.
So...
1. Are PacNor barrels especially soft?
2. Are double based powders really that evil?
3. Should I be well below max pressures if I want to maintain a reasonable barrel life even when they advertise high max pressures?
4. Is Bore Tech particularly abrasive or corrosive?
5. Is cleaning bad?
The rifle is still shooting 1/2 minute groups, but I suspect a re barrel is close. Just trying to work out what I have done wrong so I can correct for the next one.
Thanks for the help.
