Groups gone crazy after a year

Wendyj · October 9, 2016, 06:26 AM

I've been reloading my 308 with 41 grains of Varget using 178 a max and 175 smk for a year now punching clover leafs. From 30 to 98 degrees at 109 yards. I went yesterday with same loads powder primers and 2 inches best group all day. Scope good and tight. Barrel sparkling clean. I thought maybe a bad day at the range but was sighting in 7 mag for hunting season and punching sub Mia. Shot 50 rounds of 308 and two would be close and next 3 all over paper. Any advise. Barrrl still looks fine with light but I don't have access to a bore scope. Lake city and Remington brass and br2 primers. No change in prior loads.

jwrowland77 · October 9, 2016, 06:58 AM

Check your bullets relationship to the barrel. In other words, see how far off the lands you are. It's definitely changed over the last year.

Sent from my iPhone using Tapatalk

ligonierbill · October 9, 2016, 07:01 AM

What stock? Have you checked the torque on the mounting screws? If it's wood, could have swelled or warped just a little, creating a pressure point. Just one more thing to check.

Wendyj · October 9, 2016, 08:09 AM

Used Hornady bullet compareter. Still sitting.04 off lands which is what it's liked so far. Savage hog Hunter with Teflon stock. Don't have torque wrench but everything feels snug. Rechecked scope and still tight. Put boresighter back on and referenced where I know it's on. Maybe 2500 rounds through it by now. Beginning to think barrel is shot out or I need to clean a different way. Been using cxp foam and Hoppes #9 followed by tad of ballistol to prevent rust. It was grouping great about a month ago and I put it up to work with 260 bench gun for awhile.

Metal god · October 9, 2016, 08:53 AM

How many rounds have you shot it the rifle ? I have a Savage that has 3500 rounds down the pipe and the throat has eroded .070 . That has required me to adjust my seating depth to what's called chase the lands .

I also second the torque check on the action screws . Same gun as above has a accu-stock that the action screws were getting loose over time . It would cause what seemed to be inconsistent grouping until one day I shot this 10 shot group during load development .

yeah crazy right ! That was 10 shots fired consecutively about 45sec apart . When I was shooting 3 , 4 and 5 shot groups it was not as noticeable . Mainly because the double groups of the smaller groups were still sub moa kinda like this

My point is not that this is likely your issue . Just that it is something to consider . My action felt tight how ever the front action screw was 15lbs and the back was about 8lbs allowing the action to move when fired . Savage recommended 40lbs on each . How ever when I did an torque test comparing group sizes using an established load . I found that 35lbs on the front and 30 in the back produced my most consistent accuracy . I then used some Loc-tite on the screws and have not had double groups since . That was 2000 rounds ago .

Old Bill Dibble · October 9, 2016, 09:11 AM

Scope good and tight but what about the internals on the scope? I had a scope that the interior lens got loose on me and about drove me mad. Only way to check that is try a different scope.

stillquietvoice · October 9, 2016, 10:25 AM

you may have to adjust your load a little to compensate for temp variations. loads develiped at higher temps will shoot differently at lowrt temps and vice versa.

Jimro · October 9, 2016, 12:43 PM

Redo your load workup.

As you use up powder, empty space in the container increases, which helps your powder lose water, or gain water.

Even though you are using the same components and the same data, X grains of powder with 5% less water is going to react differently than it did last year.

For my Service Rifle loads, I stopped weighing charges altogether and just went with volume charge from a powder dispenser. I found that I could easily get an extra grain worth of weight for the same volume of charge depending on how long the powder had been exposed to air and had I been weighing individual charges, would have had under powered loads not at the accuracy node I was reloading for.

Jimro

1stmar · October 9, 2016, 12:51 PM

If you rechecked distance off lands than your throat hasn't changed, that's the first place the barrel will wear. If that's good it's not likely your problem. Are you cleaning from muzzle end? Besides group size what did the groups like like? Stringing? No pattern?

**Unclenick** · October 9, 2016, 12:56 PM

Wendy,

When a barrel is shot out (usually 3000-3500 rounds for chrome-moly steel in a .308 Winchester) it normally goes bad gradually. When I shot out my first M1A barrel it would group well, but about 1 in 20 shots would be out of the group. After another hundred rounds or so, it became 1 in ten. After another 100 rounds it became 1 in 5. That's about when I realized it was the barrel and not me. But unless there is some specific damage, I would not expect it to jump to a large percentage of fliers as you described.

If it's not your trigger control, then Old Bill Dibble is right to suggest the scope. The most delicate thing on the gun is the scope. With the symptom you describe, I also suspect the scope had something get loose inside. My first move would be to swap in a different scope. If that cures it, the scope needs to be sent to its maker for repair.

T. O'Heir · October 9, 2016, 01:39 PM

Shooting match ammo after shooting any kind of magnum can do that.
Your shoulder being a bit mushy is far more likely than some drastic happening to a proven rifle or load.

Wendyj · October 9, 2016, 04:10 PM

No stringing. Might get lucky and have 2 bullets almost touching and then a flyer high. One low. One left one right. Using the vortex target fro vortex nation website I would be in circle above below. I've always been able to clover lead at worst. I did just buy another 6.5 X 20 x44 viper VHS from Midway and am noticing clicks aren't prominent when moving turrets. Same scope as on my Tiikka CTR. I will pull a nightforce off another rifle and try that. I'm at a loss right now. Have actually thought about a 2.5 X 10 scope for it just to shoot steel at 500 yards or maybe change it to a hunting rifle. Not sure what to do if another scope doesn't fix it. I could try some factory match ammo but this load has worked summer winter fall spring without fail. Interesting all replies for reasons why. Powder shifting in containers. Internals of scopes. Torquing and Throat erosion. Only been doing this two years and first time this issue has come up. Great help on here.

catgunguy · October 9, 2016, 05:11 PM

How many times has the brass been loaded before? Do you anneal you brass?

Is the brass the same head stamp? It sounds like a neck tension problem.

Wendyj · October 9, 2016, 05:29 PM

178 Amax was Norma brass. 175 smk was lake city brass. All is on its 3rd loading. Shoulders set back .002. I don't anneal my brass. I do have a friend that shoots competition that doesn't reload his 308 and sells them to me for $20.00 a hundred when I've shot mine out five or six times. The Norma brass I bought and won't buy anymore. The primer pockets are too loose. Last batch I bought from friend was federal match. That's what I'll work my new loads in for next go around.

1stmar · October 9, 2016, 05:59 PM

scope sounds like a good place to start maybe couple that w the match ammo.

RC20 · October 9, 2016, 06:27 PM

Always start with the easy stuff and the Scope is one of them as well as a high suspicion as its a big jump.

Also check the bases while you have it off, more than once screws were loose when previously tight.

I don't use lock tite, on and off to many times. Check each time you have access.

Something significant though that could also be a stock issue.

October 9, 2016, 06:26 AM	#1
Wendyj Senior Member Join Date: April 3, 2015 Location: North Georgia Posts: 1,372	Groups gone crazy after a year I've been reloading my 308 with 41 grains of Varget using 178 a max and 175 smk for a year now punching clover leafs. From 30 to 98 degrees at 109 yards. I went yesterday with same loads powder primers and 2 inches best group all day. Scope good and tight. Barrel sparkling clean. I thought maybe a bad day at the range but was sighting in 7 mag for hunting season and punching sub Mia. Shot 50 rounds of 308 and two would be close and next 3 all over paper. Any advise. Barrrl still looks fine with light but I don't have access to a bore scope. Lake city and Remington brass and br2 primers. No change in prior loads. __________________ God is NOT dead!!!!

October 9, 2016, 08:09 AM	#4
Wendyj Senior Member Join Date: April 3, 2015 Location: North Georgia Posts: 1,372	Used Hornady bullet compareter. Still sitting.04 off lands which is what it's liked so far. Savage hog Hunter with Teflon stock. Don't have torque wrench but everything feels snug. Rechecked scope and still tight. Put boresighter back on and referenced where I know it's on. Maybe 2500 rounds through it by now. Beginning to think barrel is shot out or I need to clean a different way. Been using cxp foam and Hoppes #9 followed by tad of ballistol to prevent rust. It was grouping great about a month ago and I put it up to work with 260 bench gun for awhile. __________________ God is NOT dead!!!!

October 9, 2016, 08:53 AM	#5
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,875	How many rounds have you shot it the rifle ? I have a Savage that has 3500 rounds down the pipe and the throat has eroded .070 . That has required me to adjust my seating depth to what's called chase the lands . I also second the torque check on the action screws . Same gun as above has a accu-stock that the action screws were getting loose over time . It would cause what seemed to be inconsistent grouping until one day I shot this 10 shot group during load development . yeah crazy right ! That was 10 shots fired consecutively about 45sec apart . When I was shooting 3 , 4 and 5 shot groups it was not as noticeable . Mainly because the double groups of the smaller groups were still sub moa kinda like this My point is not that this is likely your issue . Just that it is something to consider . My action felt tight how ever the front action screw was 15lbs and the back was about 8lbs allowing the action to move when fired . Savage recommended 40lbs on each . How ever when I did an torque test comparing group sizes using an established load . I found that 35lbs on the front and 30 in the back produced my most consistent accuracy . I then used some Loc-tite on the screws and have not had double groups since . That was 2000 rounds ago . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

October 9, 2016, 09:11 AM	#6
Old Bill Dibble Senior Member Join Date: July 25, 2016 Posts: 802	Scope good and tight but what about the internals on the scope? I had a scope that the interior lens got loose on me and about drove me mad. Only way to check that is try a different scope. __________________ "Tragedy has been and will always be with us. Somewhere right now, evil people are planning evil things. All of us will do everything meaningful, everything we can do to prevent it, but each horrible act can’t become an axe for opportunists to cleave the very Bill of Rights that binds us."

October 9, 2016, 10:25 AM	#7
stillquietvoice Senior Member Join Date: November 13, 2015 Location: UPSTATE NY Posts: 179	you may have to adjust your load a little to compensate for temp variations. loads develiped at higher temps will shoot differently at lowrt temps and vice versa. __________________ actions speak louder than words flatter tragectories quicker results.

October 9, 2016, 06:58 AM	#2
jwrowland77 Senior Member Join Date: March 23, 2012 Location: Conway, Arkansas Posts: 1,398	Check your bullets relationship to the barrel. In other words, see how far off the lands you are. It's definitely changed over the last year. Sent from my iPhone using Tapatalk

October 9, 2016, 07:01 AM	#3
ligonierbill Senior Member Join Date: May 20, 2007 Posts: 2,448	What stock? Have you checked the torque on the mounting screws? If it's wood, could have swelled or warped just a little, creating a pressure point. Just one more thing to check.

October 9, 2016, 12:43 PM	#8
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	Redo your load workup. As you use up powder, empty space in the container increases, which helps your powder lose water, or gain water. Even though you are using the same components and the same data, X grains of powder with 5% less water is going to react differently than it did last year. For my Service Rifle loads, I stopped weighing charges altogether and just went with volume charge from a powder dispenser. I found that I could easily get an extra grain worth of weight for the same volume of charge depending on how long the powder had been exposed to air and had I been weighing individual charges, would have had under powered loads not at the accuracy node I was reloading for. Jimro __________________ Machine guns are awesome until you have to carry one.

October 9, 2016, 12:51 PM	#9
1stmar Senior Member Join Date: March 21, 2012 Location: Connecticut Posts: 2,378	If you rechecked distance off lands than your throat hasn't changed, that's the first place the barrel will wear. If that's good it's not likely your problem. Are you cleaning from muzzle end? Besides group size what did the groups like like? Stringing? No pattern?

October 9, 2016, 12:56 PM	#10
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Wendy, When a barrel is shot out (usually 3000-3500 rounds for chrome-moly steel in a .308 Winchester) it normally goes bad gradually. When I shot out my first M1A barrel it would group well, but about 1 in 20 shots would be out of the group. After another hundred rounds or so, it became 1 in ten. After another 100 rounds it became 1 in 5. That's about when I realized it was the barrel and not me. But unless there is some specific damage, I would not expect it to jump to a large percentage of fliers as you described. If it's not your trigger control, then Old Bill Dibble is right to suggest the scope. The most delicate thing on the gun is the scope. With the symptom you describe, I also suspect the scope had something get loose inside. My first move would be to swap in a different scope. If that cures it, the scope needs to be sent to its maker for repair. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 9, 2016, 01:39 PM	#11
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	Shooting match ammo after shooting any kind of magnum can do that. Your shoulder being a bit mushy is far more likely than some drastic happening to a proven rifle or load. __________________ Spelling and grammar count!

October 9, 2016, 04:10 PM	#12
Wendyj Senior Member Join Date: April 3, 2015 Location: North Georgia Posts: 1,372	No stringing. Might get lucky and have 2 bullets almost touching and then a flyer high. One low. One left one right. Using the vortex target fro vortex nation website I would be in circle above below. I've always been able to clover lead at worst. I did just buy another 6.5 X 20 x44 viper VHS from Midway and am noticing clicks aren't prominent when moving turrets. Same scope as on my Tiikka CTR. I will pull a nightforce off another rifle and try that. I'm at a loss right now. Have actually thought about a 2.5 X 10 scope for it just to shoot steel at 500 yards or maybe change it to a hunting rifle. Not sure what to do if another scope doesn't fix it. I could try some factory match ammo but this load has worked summer winter fall spring without fail. Interesting all replies for reasons why. Powder shifting in containers. Internals of scopes. Torquing and Throat erosion. Only been doing this two years and first time this issue has come up. Great help on here. __________________ God is NOT dead!!!!

October 9, 2016, 05:11 PM	#13
catgunguy Member Join Date: March 11, 2014 Posts: 37	How many times has the brass been loaded before? Do you anneal you brass? Is the brass the same head stamp? It sounds like a neck tension problem.

October 9, 2016, 05:29 PM	#14
Wendyj Senior Member Join Date: April 3, 2015 Location: North Georgia Posts: 1,372	178 Amax was Norma brass. 175 smk was lake city brass. All is on its 3rd loading. Shoulders set back .002. I don't anneal my brass. I do have a friend that shoots competition that doesn't reload his 308 and sells them to me for $20.00 a hundred when I've shot mine out five or six times. The Norma brass I bought and won't buy anymore. The primer pockets are too loose. Last batch I bought from friend was federal match. That's what I'll work my new loads in for next go around. __________________ God is NOT dead!!!!

October 9, 2016, 05:59 PM	#15
1stmar Senior Member Join Date: March 21, 2012 Location: Connecticut Posts: 2,378	scope sounds like a good place to start maybe couple that w the match ammo.

October 9, 2016, 06:27 PM	#16
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	Always start with the easy stuff and the Scope is one of them as well as a high suspicion as its a big jump. Also check the bases while you have it off, more than once screws were loose when previously tight. I don't use lock tite, on and off to many times. Check each time you have access. Something significant though that could also be a stock issue.