Hello,
Long time forum lurker here and been on the site for a long time. Love Snipers Hide forums and some of the best information on the web.
I would have likely continued to lurk forever, but finally found a problem I just simply cannot answer for myself.
So, in a new post, I have a question for anyone who is a gunsmith, or maybe get some type of answer to what's going on.
I ordered a new, completed 308 upper from CMMG a few months ago. Upper arrived, looked fairly new, but barrel and bolt carrier were pretty dirty. Looked like when they fired the test rounds, they'd been using black powder and rolled it through the mud a couple of times. But I'm use to the factory not cleaning barrels now, so no biggie. Broke out the cleaning equipment and made it all purdy again.
Went out to shoot some factory ammunition, it would hold a somewhat tight group, 1-1/2 MOA in a 3 round group. It's not a match upper, so I was satisfied as I could likely improve it with hand loads. Continued the break in period, cleaning between each round.. then, on the 5th shot, it threw a random flier out about 5 inches to the side.
Now I knew I drank a little coffee that day, but not that much. Maybe bad ammo? I didn't know. So shot the rest of a 10 round group, 2 more fliers, 6-7 inches off, while the rest would somehow end up in my group.
Frustrated, I went back to my shop, cleaned the gun up thoroughly and decided to make some of my never fail, medium grade handloads. I load mid-range, but accuracy is more important than speed any day.
Couple days later, I went out to my usual shooting area, shot 1" MOA with the first 5 rounds. Was pretty happy, thought my starting loads were dead on, thought the problem was fixed. Continued the break-in procedure and the next 2 shots, fliers that were 6-7 inches off center.
My shooting is prone, with bipod and using my match Lilja 308 upper, I usually group .42" @ 100 yrds. I knew it wasn't me.
So, convinced something is wrong with the rifle, and wanting to also put a muzzle brake on it, I took it to a gunsmith here local to see if his expertise would diagnose the problem. He pulled the factory CMMG flash hider off the barrel and voila... about 3/8" down the crown, upper portion of the barrel, we see the following:
Notice in the attached pictures, the groove in the barrel crown. Note the copper fouling ends before it touches the rifling where the barrel is smaller diameter in that area than it is anywhere else. Measuring with calipers, it is a couple thousandth's smaller in that area. I believe that this is what is causing my random flier issue.
I got frustrated... so called CMMG. They issued me an RMA. Not wanting to wait that long, I was already in the process of building a match LR308 upper, using a Lilja match barrel, SI-Defense upper, and complete JP enterprises host of add-ons with their Low Mass Operating System bolt carrier. I'm just so happy with the new upper (which cost me an absolute fortune at this point lol) but I still want to build up a nice, low weight hunting upper to go terrorize the hogs that insist on stalking our property and uprooting every plant in the neighborhood.
So I definitely want this upper, and I want it to be a good boy and shoot correctly, not string shots out. I can live with 1-1/2" groups using factory ammunition if needed. My OCD with factory rifles has been fully tamed. If I want to shoot a field mouse at 300 yards, I'll simply put my new match barrel on it because I spared no expense in the process.
Well, here's what CMMG told me.
They sent back my barrel today. They thought the tip of the crown looked a little rough, so they recrowned it. They didn't take anything off the barrel, ( didn't shorten it) and they shot a test group with the old barrel I sent them. They told me a 10 round group all measured 1 MOA but they didn't get it to string a flier. They told me that the error did't warrant replacing the barrel, because they couldn't see anything wrong.
Very frustrated, but maybe they're right and a barrel can live with this type of imperfection in the crown and possibly it's something else causing the issue.
If it is the crown causing the problem, I think CMMG is going to leave me hanging on this, because they said they wouldn't replace the barrel because it fired a test group ok.
Besides using the CMMG upper to buy and build a new Match Lilja upper, I honestly think I'm out $1100, minus the upper I used on my new gun.
I have a CNC machine for my business, as well as numerous precision lathe and tools. I could possibly send a bore bit down into the rifling 3/8" or until the flaw in the crown is gone, so basically my crown would start at the flaw. Or maybe I should cut it off at that length, tap and thread the barrel for my new muzzle brake.
I'm just very frustrated at this point because the factory won't replace it, or even modify the barrel to remove the flaw under warranty. The barrel is 18", so cutting off some length would still be legal.
Or, possibly I'm the one smoking crack here and the barrel should be ok with a flaw like this and I'm jerking the trigger. (not the case as I can usually hit 6" steel plates consistently at 600 yards with my Lilja match upper all day now if it's not windy, and I do my part, I hit it every time.
Sorry for a such a long post, but wanted to be detailed as possible here to show the history and timeline.
Rifle barrel has had about 100 rounds through it, plus whatever the factory shot, and approximately 1 in every 5 rounds I fire is a rogue flier. All I know, for the price of ammo now days, I might be better to simply turn the barrel into a spare crowbar around my show for beating random metal objects with it and spend $300 - $350 and buy a new Lilja barrel to replace it and not look back.
Thank you for any answers or responses you might have. Just really have no place else to turn as I'm in a remote, rural area. Only one gunsmith within 100 miles of me. Also thanks to Snipers Hide and the users of this forum for putting together one of the best sources of information available on the web.
Hope my images post correctly or I will have to re-submit to the web.
Long time forum lurker here and been on the site for a long time. Love Snipers Hide forums and some of the best information on the web.
I would have likely continued to lurk forever, but finally found a problem I just simply cannot answer for myself.
So, in a new post, I have a question for anyone who is a gunsmith, or maybe get some type of answer to what's going on.
I ordered a new, completed 308 upper from CMMG a few months ago. Upper arrived, looked fairly new, but barrel and bolt carrier were pretty dirty. Looked like when they fired the test rounds, they'd been using black powder and rolled it through the mud a couple of times. But I'm use to the factory not cleaning barrels now, so no biggie. Broke out the cleaning equipment and made it all purdy again.
Went out to shoot some factory ammunition, it would hold a somewhat tight group, 1-1/2 MOA in a 3 round group. It's not a match upper, so I was satisfied as I could likely improve it with hand loads. Continued the break in period, cleaning between each round.. then, on the 5th shot, it threw a random flier out about 5 inches to the side.
Now I knew I drank a little coffee that day, but not that much. Maybe bad ammo? I didn't know. So shot the rest of a 10 round group, 2 more fliers, 6-7 inches off, while the rest would somehow end up in my group.
Frustrated, I went back to my shop, cleaned the gun up thoroughly and decided to make some of my never fail, medium grade handloads. I load mid-range, but accuracy is more important than speed any day.
Couple days later, I went out to my usual shooting area, shot 1" MOA with the first 5 rounds. Was pretty happy, thought my starting loads were dead on, thought the problem was fixed. Continued the break-in procedure and the next 2 shots, fliers that were 6-7 inches off center.
My shooting is prone, with bipod and using my match Lilja 308 upper, I usually group .42" @ 100 yrds. I knew it wasn't me.
So, convinced something is wrong with the rifle, and wanting to also put a muzzle brake on it, I took it to a gunsmith here local to see if his expertise would diagnose the problem. He pulled the factory CMMG flash hider off the barrel and voila... about 3/8" down the crown, upper portion of the barrel, we see the following:
Notice in the attached pictures, the groove in the barrel crown. Note the copper fouling ends before it touches the rifling where the barrel is smaller diameter in that area than it is anywhere else. Measuring with calipers, it is a couple thousandth's smaller in that area. I believe that this is what is causing my random flier issue.
I got frustrated... so called CMMG. They issued me an RMA. Not wanting to wait that long, I was already in the process of building a match LR308 upper, using a Lilja match barrel, SI-Defense upper, and complete JP enterprises host of add-ons with their Low Mass Operating System bolt carrier. I'm just so happy with the new upper (which cost me an absolute fortune at this point lol) but I still want to build up a nice, low weight hunting upper to go terrorize the hogs that insist on stalking our property and uprooting every plant in the neighborhood.
So I definitely want this upper, and I want it to be a good boy and shoot correctly, not string shots out. I can live with 1-1/2" groups using factory ammunition if needed. My OCD with factory rifles has been fully tamed. If I want to shoot a field mouse at 300 yards, I'll simply put my new match barrel on it because I spared no expense in the process.
Well, here's what CMMG told me.
They sent back my barrel today. They thought the tip of the crown looked a little rough, so they recrowned it. They didn't take anything off the barrel, ( didn't shorten it) and they shot a test group with the old barrel I sent them. They told me a 10 round group all measured 1 MOA but they didn't get it to string a flier. They told me that the error did't warrant replacing the barrel, because they couldn't see anything wrong.
Very frustrated, but maybe they're right and a barrel can live with this type of imperfection in the crown and possibly it's something else causing the issue.
If it is the crown causing the problem, I think CMMG is going to leave me hanging on this, because they said they wouldn't replace the barrel because it fired a test group ok.
Besides using the CMMG upper to buy and build a new Match Lilja upper, I honestly think I'm out $1100, minus the upper I used on my new gun.
I have a CNC machine for my business, as well as numerous precision lathe and tools. I could possibly send a bore bit down into the rifling 3/8" or until the flaw in the crown is gone, so basically my crown would start at the flaw. Or maybe I should cut it off at that length, tap and thread the barrel for my new muzzle brake.
I'm just very frustrated at this point because the factory won't replace it, or even modify the barrel to remove the flaw under warranty. The barrel is 18", so cutting off some length would still be legal.
Or, possibly I'm the one smoking crack here and the barrel should be ok with a flaw like this and I'm jerking the trigger.
(not the case as I can usually hit 6" steel plates consistently at 600 yards with my Lilja match upper all day now if it's not windy, and I do my part, I hit it every time.Sorry for a such a long post, but wanted to be detailed as possible here to show the history and timeline.
Rifle barrel has had about 100 rounds through it, plus whatever the factory shot, and approximately 1 in every 5 rounds I fire is a rogue flier. All I know, for the price of ammo now days, I might be better to simply turn the barrel into a spare crowbar around my show for beating random metal objects with it and spend $300 - $350 and buy a new Lilja barrel to replace it and not look back.
Thank you for any answers or responses you might have. Just really have no place else to turn as I'm in a remote, rural area. Only one gunsmith within 100 miles of me. Also thanks to Snipers Hide and the users of this forum for putting together one of the best sources of information available on the web.
Hope my images post correctly or I will have to re-submit to the web.
