FN49 Gas Adj inputs

k98dave · December 1, 2016, 10:16 AM

Got to the range yesterday to check out the FN using my standard M1 loaded match ammo which is 47.0 gns of 4064 under a 168 FMJBT. As expected accuracy was on par with my M1, about 1.5" @ 100yrds.

I am waiting for the gas vent adj tool to come in the mail. The ejection was robust, the brass wasn't damaged in any way but thrown about 10-12ft out to the 2 O'clock.

The gas sleeve appears to be just very slightly open and from the looks of it it may just be the factory setting as there are no signs of it being adjusted.

This load in the M1 puts the cases about 6" out and almost in a neat little 3' circle. I plan to get back out when the tool arrives and open up the port slightly to see if I can turn down the way the brass gets thrown out while still having good action cycles. Any suggestions or inputs appreciated!

tangolima · December 1, 2016, 10:45 AM

I have a fn49 in 8mm. I end up opening the gas port 100%, minimum gas to cycle the action. The factory setting actually dents the brass. The ejection is still rather vigorous as it is. Accuracy is about 2" @100yd. Not great but reasonable.

BTW, you don't really need the tool to adjust the sleeve. It is nice to have the tool though.

Does your rifle have the cross bolt as the recoil bearing surface? Mine doesn't. It took me a while to figure out where the recoil force goes from the metal to the wood. It is rather unconventional.

-TL

December 1, 2016, 10:16 AM	#1
k98dave Junior Member Join Date: November 2, 2016 Posts: 11	FN49 Gas Adj inputs Got to the range yesterday to check out the FN using my standard M1 loaded match ammo which is 47.0 gns of 4064 under a 168 FMJBT. As expected accuracy was on par with my M1, about 1.5" @ 100yrds. I am waiting for the gas vent adj tool to come in the mail. The ejection was robust, the brass wasn't damaged in any way but thrown about 10-12ft out to the 2 O'clock. The gas sleeve appears to be just very slightly open and from the looks of it it may just be the factory setting as there are no signs of it being adjusted. This load in the M1 puts the cases about 6" out and almost in a neat little 3' circle. I plan to get back out when the tool arrives and open up the port slightly to see if I can turn down the way the brass gets thrown out while still having good action cycles. Any suggestions or inputs appreciated! Last edited by k98dave; December 1, 2016 at 10:22 AM.

December 1, 2016, 10:45 AM	#2
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,824	I have a fn49 in 8mm. I end up opening the gas port 100%, minimum gas to cycle the action. The factory setting actually dents the brass. The ejection is still rather vigorous as it is. Accuracy is about 2" @100yd. Not great but reasonable. BTW, you don't really need the tool to adjust the sleeve. It is nice to have the tool though. Does your rifle have the cross bolt as the recoil bearing surface? Mine doesn't. It took me a while to figure out where the recoil force goes from the metal to the wood. It is rather unconventional. -TL