Ok, first a little background on the rifle and the situation.
I have an FN A5-M that all of a sudden is no longer able to hold a group.
This happened while in the final stages of load development.
After becoming frustrated with not being able to get any of my newly developed loads to hold a group under 1 & 1/2 inches at 100 yards,
I tested it with known good factory ammunition (GMM) with the same result.
My next step was to use some Boretech Eliminator to completely remove any copper fouling that may be present.
(I normally only use Hoppes #9 and let it ride.)
I also used my Seekonic torque wrench on the action and rings to ensure they were not loose.
After that, I scheduled a range session with my shooting partner for another round of testing.
This time I had my partner shoot all of the test shots so that my shooting could be ruled out as a cause.
The test was a round robin test on 8 targets using 4 different factory loads and 4 different hand loads.
Best group was 1 inch at 100 yards and it was with one of my hand loads.
All velocities were logged and the ES of the four hand loads was no greater than 1 fps for each loading respectively.
For anyone that may not know the history of the FN SPR and their issues:
FN uses a hammer forged chrome lined barrel in their SPR line of rifles.
When they announced that they were closing the Winchester plant in Conn,
mysterious problems began to manifest themselves in the chrome lining of these rifles.
My rifle was identified as having a defective bore and was replaced by FN.
As compensation for my troubles, FN handpicked a new rifle out of their warehouse with the best test target.
This rifle was then sent to GAP to be bedded in the same fashion as their A3G rifles.
When the rifle was returned from GAP to FN, the rifle was retested and shot a test group of .260 inches at 100 yards.
I have been able to replicate these results regularly with factory ammo and was getting even better results with my initial hand loads.
There have been reports that around the 800 round mark, some of the FN SPR chrome lined barrels begin to have additional problems with the chrome.
My round count is 760 and this makes me fearful that I may be having problems with the bore.
The reason for this post is to try and confirm my thought process as well as to solicit any additional advice & theories from the community.
My next steps will be thoroughly clean the bore and check out a bore scope from work to see if I can see anything.
In addition to that, I will remove the action from the stock to check for any deris.
Then I'll remove the scope from the base so I can re-torque it.
I have another optic that I will throw on there so I can rule that out too.
If it still can't hold a better group after all that, I'm afraid that I will have to bite the bullet and send her off to GAP to be re-barreled.
Any suggestions are greatly appreciated.
Cheers!
I have an FN A5-M that all of a sudden is no longer able to hold a group.
This happened while in the final stages of load development.
After becoming frustrated with not being able to get any of my newly developed loads to hold a group under 1 & 1/2 inches at 100 yards,
I tested it with known good factory ammunition (GMM) with the same result.
My next step was to use some Boretech Eliminator to completely remove any copper fouling that may be present.
(I normally only use Hoppes #9 and let it ride.)
I also used my Seekonic torque wrench on the action and rings to ensure they were not loose.
After that, I scheduled a range session with my shooting partner for another round of testing.
This time I had my partner shoot all of the test shots so that my shooting could be ruled out as a cause.
The test was a round robin test on 8 targets using 4 different factory loads and 4 different hand loads.
Best group was 1 inch at 100 yards and it was with one of my hand loads.
All velocities were logged and the ES of the four hand loads was no greater than 1 fps for each loading respectively.
For anyone that may not know the history of the FN SPR and their issues:
FN uses a hammer forged chrome lined barrel in their SPR line of rifles.
When they announced that they were closing the Winchester plant in Conn,
mysterious problems began to manifest themselves in the chrome lining of these rifles.
My rifle was identified as having a defective bore and was replaced by FN.
As compensation for my troubles, FN handpicked a new rifle out of their warehouse with the best test target.
This rifle was then sent to GAP to be bedded in the same fashion as their A3G rifles.
When the rifle was returned from GAP to FN, the rifle was retested and shot a test group of .260 inches at 100 yards.
I have been able to replicate these results regularly with factory ammo and was getting even better results with my initial hand loads.
There have been reports that around the 800 round mark, some of the FN SPR chrome lined barrels begin to have additional problems with the chrome.
My round count is 760 and this makes me fearful that I may be having problems with the bore.
The reason for this post is to try and confirm my thought process as well as to solicit any additional advice & theories from the community.
My next steps will be thoroughly clean the bore and check out a bore scope from work to see if I can see anything.
In addition to that, I will remove the action from the stock to check for any deris.
Then I'll remove the scope from the base so I can re-torque it.
I have another optic that I will throw on there so I can rule that out too.
If it still can't hold a better group after all that, I'm afraid that I will have to bite the bullet and send her off to GAP to be re-barreled.
Any suggestions are greatly appreciated.
Cheers!
