SimpleMind949
Active Member
- Joined
- Feb 8, 2017
- Messages
- 25
Let me preference this by letting you know that I am new to this, so I really any support you may be able to provide.
I recently purchased a Remington 700 Long Range in 7mm Rem Mag and have been breaking it in following a couple different regiments. The first regiment was by shooting 20 rounds (I used Hornady 165g ELD-X) cleaning with Hoppe's 9 after each of the first 5 shots and then after every 5th shot. I then shot 20 more rounds waiting for the chamber and barrel to cool between each shot. I tracked ammo and bore temperature as well as muzzle velocity. The ammo and temperature stayed very consistent and the muzzle velocity, as expected, slowly increased from low 2800s to mid 2900s. On the 38th and then the 40th round I had a difficult time ejecting the cartridge with no excessive change in velocity. Concerned, I stopped shooting for the day and consulted a more experienced friend who was concerned that the issue may be a pressure issue caused by excessive copper accumulation. I inspected the cartridges for other pressure signs including flatten primers and increased diameter at the belt, but all the primers looked the same and the diameter was only increasing on average .0016". So at that, point not knowing what else to do, I decided to follow a more comprehensive cleaning regiment which included copper removal using Sweets 7.62.
Before returning to the field I first did a thorough cleaning and removed all traces of copper. This time I followed the following regiment; Shoot 1 shot and clean with Shooters Choice on brush and then with Sweets on patch removing all the copper for the first 30 shots and then every 5th shoot for the next 30 rounds. This took several trips to the range. I used Federal 150g Trophy Copper this time and tracked case diameter change, ammo and chamber temperature, and muzzle velocity. The last 30 rounds I also tracked accuracy. I did not have any problems with stuck cartridges until the 53 and 55 shots which were both a bit sticky. After cleaning again the last 5 shots went fine. My groups through the last 30 shots were not great, 1.7 to 3.1 MOA. So at that point I started trying other factory ammo to see if I could get anything to group. I shot two 5 round groups of Black Hills Gold 139g GMX with horrible results, 4.854 and 4.778 MOA. Muzzle velocity averaged 3064 with an standard div. of 26 and extreme spread of 78 fps and had two sticky cartridges on the 7th and 9th shot. I then cleaned and removed the copper again and tried HSM Trophy Gold 168g Berger VLD. The first shot was a dead bull's-eye but the cartridge was so stuck I could not remove it until I got home and used a rubber mallet. I inspected the brass and was able to take the picture below showing scratches that continue around the circumference of the cartridge, however there was only a .0042" increase in diameter at the belt.
Needles to say, I am at a loss of how to proceed and I would really appreciate any suggestions.
Cheers!
I recently purchased a Remington 700 Long Range in 7mm Rem Mag and have been breaking it in following a couple different regiments. The first regiment was by shooting 20 rounds (I used Hornady 165g ELD-X) cleaning with Hoppe's 9 after each of the first 5 shots and then after every 5th shot. I then shot 20 more rounds waiting for the chamber and barrel to cool between each shot. I tracked ammo and bore temperature as well as muzzle velocity. The ammo and temperature stayed very consistent and the muzzle velocity, as expected, slowly increased from low 2800s to mid 2900s. On the 38th and then the 40th round I had a difficult time ejecting the cartridge with no excessive change in velocity. Concerned, I stopped shooting for the day and consulted a more experienced friend who was concerned that the issue may be a pressure issue caused by excessive copper accumulation. I inspected the cartridges for other pressure signs including flatten primers and increased diameter at the belt, but all the primers looked the same and the diameter was only increasing on average .0016". So at that, point not knowing what else to do, I decided to follow a more comprehensive cleaning regiment which included copper removal using Sweets 7.62.
Before returning to the field I first did a thorough cleaning and removed all traces of copper. This time I followed the following regiment; Shoot 1 shot and clean with Shooters Choice on brush and then with Sweets on patch removing all the copper for the first 30 shots and then every 5th shoot for the next 30 rounds. This took several trips to the range. I used Federal 150g Trophy Copper this time and tracked case diameter change, ammo and chamber temperature, and muzzle velocity. The last 30 rounds I also tracked accuracy. I did not have any problems with stuck cartridges until the 53 and 55 shots which were both a bit sticky. After cleaning again the last 5 shots went fine. My groups through the last 30 shots were not great, 1.7 to 3.1 MOA. So at that point I started trying other factory ammo to see if I could get anything to group. I shot two 5 round groups of Black Hills Gold 139g GMX with horrible results, 4.854 and 4.778 MOA. Muzzle velocity averaged 3064 with an standard div. of 26 and extreme spread of 78 fps and had two sticky cartridges on the 7th and 9th shot. I then cleaned and removed the copper again and tried HSM Trophy Gold 168g Berger VLD. The first shot was a dead bull's-eye but the cartridge was so stuck I could not remove it until I got home and used a rubber mallet. I inspected the brass and was able to take the picture below showing scratches that continue around the circumference of the cartridge, however there was only a .0042" increase in diameter at the belt.
Needles to say, I am at a loss of how to proceed and I would really appreciate any suggestions.
Cheers!
