AR10 300 WSM build. Need advice

blackgunbuilder · October 15, 2013, 11:13 PM

I am currently doing my first 300WSM build for a customer and I am having some unforeseen issues. I have having cycling issues. I built the gun to his specific specs and I think one may have me searching for a solution. He wanted the gas block under the 13" hand guard so I had to go with a mid length gas port. Now I am have premature bolt opening issues causing a short stroke problem. I think. Here is what is happening, with a lighter buffer spring or a standard AR-10 spring I am not getting the bolt to catch, suggesting a short stroke, everything cycles and clears by hand with no issues. Here is my plan, I plan to swap the standard gas block with a adjustable block and going to a number 5 port size, going to a heavier buffer spring to delay bolt opening. Has anyone built a 300WSM in this platform and how did you fix the bugs and am I correct on my cycling problems. Here are the specs, DPMS style matched billet upper lower, 20" precision barrel with break/comp, A2 buffer tube, niB BCG and I have shot pretty much every factory load out there with same results. 180 and 165 gr bullets. Any and all help and suggestions would be greatly appreciated.

blackgunbuilder · October 15, 2013, 11:20 PM

Also if I load more than 5 rounds in the mag the first round either doesn't cycle in, or doesn't eject and the next round jams on the feed ramps, but if I load five or less in the mag I don't have this problem and everything cycles fine except the bolt doesn't catch on the last round. This gun has been a frustration from the start. I have built 100s or ARs and never had issues quite like this before.

October 15, 2013, 11:13 PM	#1
blackgunbuilder Junior Member Join Date: October 14, 2013 Posts: 2	AR10 300 WSM build. Need advice I am currently doing my first 300WSM build for a customer and I am having some unforeseen issues. I have having cycling issues. I built the gun to his specific specs and I think one may have me searching for a solution. He wanted the gas block under the 13" hand guard so I had to go with a mid length gas port. Now I am have premature bolt opening issues causing a short stroke problem. I think. Here is what is happening, with a lighter buffer spring or a standard AR-10 spring I am not getting the bolt to catch, suggesting a short stroke, everything cycles and clears by hand with no issues. Here is my plan, I plan to swap the standard gas block with a adjustable block and going to a number 5 port size, going to a heavier buffer spring to delay bolt opening. Has anyone built a 300WSM in this platform and how did you fix the bugs and am I correct on my cycling problems. Here are the specs, DPMS style matched billet upper lower, 20" precision barrel with break/comp, A2 buffer tube, niB BCG and I have shot pretty much every factory load out there with same results. 180 and 165 gr bullets. Any and all help and suggestions would be greatly appreciated.

October 15, 2013, 11:20 PM	#2
blackgunbuilder Junior Member Join Date: October 14, 2013 Posts: 2	Also if I load more than 5 rounds in the mag the first round either doesn't cycle in, or doesn't eject and the next round jams on the feed ramps, but if I load five or less in the mag I don't have this problem and everything cycles fine except the bolt doesn't catch on the last round. This gun has been a frustration from the start. I have built 100s or ARs and never had issues quite like this before.