Need help interpreting targets

[USSR]

@USSR, which do you think is the greater variable:

-hand loads with Sierra 150gr GameKings on top of IMR4895, measured to +/-0.1gr accuracy, using same 1x brass and primers, which through 9-shot groups of 4 different charges have shown the most consistency

or

-a completely unknown rifle (barrel, action, stock, scope mount, scope)

I am experienced at troubleshooting other types of problems, but unfortunately not at troubleshooting inconsistent groups. So given my experience with this rifle so far, I would expect the scope and/or mount and the shooter to now be the greatest variables. I am not opposed to buying a box of match grade ammo, I just want to do my best to eliminate the most likely problem first.

Assuming you have first checked you scope mounts for not being loose and tried a different scope that is known to be good, then the next step I would take is going with a load with a known history (Federal Gold Medal Match), so as to develop a baseline and eliminate your reloads as a factor.

USSR, Sorry to bust your bubble, but ALL factory ammo, including "match grade", is still more prone to inconsistencies than a careful hand-loader. The OP hand-loads and seems to know what he is doing in that respect. Unless that factory hand weighs each and every charge (and no Fed Match Grade is NOT), and every charge comes from the same lot, (Again Fed Match Grade is not), then there is no possible way to be as consistent as a careful hand-loader. Plain and simple. So that "base line" is not really a base line at all. A careful hand-loader would be able to provide a much more consistent load value than ANY mass produced ammo.

Hmm, if all that is necessary to develop extremely accurate ammo is consistency and being careful, then all handloads would be accurate and there would be no need for load development work. You can develop various handloads, all carefully and consistently put together using different powders, charge weights, COAL's, primers, etc., and you will have varying degrees of accuracy. As previously stated "If the rifle doesn't group well with FGMM, something is wrong with the rifle". It's all about eliminating a variable; his handloads.

Don

 

[Freedom_fighter_in_IL]

As previously stated "If the rifle doesn't group well with FGMM, something is wrong with the rifle". It's all about eliminating a variable; his handloads

No it would rule out "that particular load". He just needs to continue varying his loads until he lands on one his particular rifle likes. As I said previously, I have three VERY good shooters that couldn't consistently hit the broad side of a barn from the inside with Fed Match. To say something is wrong with a rifle because it doesn't group well with Fed Match is just plain silly. Yes they are generally a good ammo for range and generally shoot well in most rifles. But not ALL rifles. Some rifles are just picky as hell. Just because it is a "known history" doesn't really mean anything except it has a good reputation for a factory loaded product.

 

[USSR]

Yes they are generally a good ammo for range and generally shoot well in most rifles.

Thanks for validating my point.

Don

 

[R.W.Dale]

Bad scope.
Plain and simple

Ditch the see thru rings too while your at it. They aren't helping.

Try a flat based bullet. IMO they're much easier to get good groups out of than boat tail bullets when testing a rifles accuracy potential.

Skip the FGMM. You can't hunt with the stuff and even if it shoots good you still have to get this rifle to shoot HUNTING bullets satisfactory

posted via mobile device.

 

[gamestalker]

If your groups are degrading that quickly, I would second the notion to lap the barrel.

You didn't say anything about barrel cool down time between shots. I give the barrel about 5 minutes cool down between shots and it seems to do the trick.

 

[bubba15301]

bad scope- need to glasbed the stock

 

[wsryno]

@ussr: I haven't yet swapped out old, unknown scope and see-through mounts with known good scope and mounts yet. That is this weekend's project.

@bubba et al: bad scope and glass bed the stock, replacing the scope/mount is in the works. Would you agree that of the two variables, scope and glass bedding, that in most cases the scope would be the one to cause the greatest variation? (assuming the barrel is free floating, which in this case it is)

@RWDale: From what I've read flat base bullets may be more accurate in this rifle. Assuming I am able to squish down the groups with known good glass and mounts, I will try Sierra Pro Hunter and see if I can squish them a bit more. This is probably a better hunting bullet for me anyway; given my current hunting grounds I can't see a shot greater than 150 yards.

@freedomfighter & ussr: For the next phase of troubleshooting, I will use the same hand load that has shown the best groups and most consistency until I've eliminated the next greatest variable(s). Again, all else being equal, I think the scope/mount/bedding/stock are probably greater variables than my ability to load rounds that are as consistent than even match grade ammo, and are verified in the rifle. (I have dialed in sub-moa loads in my .270 so I know enough to be dangerous with a stack of bullet making supplies.)

@gamestalker: 5 minutes between shots? I don't mind spending the whole day at the range but my wife, well she doesn't understand 1 hour to squeeze off 12 rounds... @nickn10 suggested a minute between shots. That's a wide range.

 

[Freedom_fighter_in_IL]

@freedomfighter & ussr: For the next phase of troubleshooting, I will use the same hand load that has shown the best groups and most consistency until I've eliminated the next greatest variable(s). Again, all else being equal, I think the scope/mount/bedding/stock are probably greater variables than my ability to load rounds that are as consistent than even match grade ammo, and are verified in the rifle. (I have dialed in sub-moa loads in my .270 so I know enough to be dangerous with a stack of bullet making supplies.)

Didn't doubt it a bit. Was just busting at the people that think just because it says "Match" on the box that every rifle will be able to shoot it accurately and that, if they don't, then something was wrong with the rifle. Not all rifles like it. And some, like a few of mine, actually hate the stuff. And as someone else pointed out, trying to get a hunting rifle to shoot good groups with match grade ammo is not the brightest move to make.

I am in definite agreement with the scope and mounts more than likely being your problem. More than likely it's the see through rings. Those, generally, are not the best in performance. Get you a quality set of base and rings and try that scope. If that doesn't solve your issue, try another scope. If that still yet doesn't cure it up, then a good bedding job may well be in order. Though that one is doubtful since you said the barrel is already free floating. It could very well be that you may need some forearm tip pressure ON the barrel. Had a few like that. The would generally string UP. Once I added a bit of pressure from the forearm tip, cloverleafs.

Rifles are a wonderful thing but like any wonderful thing, they can make you want to pull your damn hair out by the roots!

 

[nickn10]

from wysrno:

[gamestalker: 5 minutes between shots? I don't mind spending the whole day at the range but my wife, well she doesn't understand 1 hour to squeeze off 12 rounds... @nickn10 suggested a minute between shots. That's a wide range.]

to wysrno:
I use 1 minute with the following steps, fire fouling shot then wait one minute
fire next shot, remove bolt, stand rifle vertically in the shade, feel with hand to get approx same barrel temperature, fire 2nd shot, repeat. Consistency is the goal, firing the rifle is the last step in the process.
Nick

 

[wsryno]

Mods: Installed known-good scope with new steel rings. Bore sighted.

Range day: At 25yds, shot 3 individual shots, adjusting scope between each one to bring impact near center. At 50 yards, 3 3-shot groups with 2 minutes pause between each shot, all groups well under 1", last group the shots were all touching.

Diagnosis: Initially very bad copper fouling, when fixed the bad scope/rings showed themselves. So I've installed the "bad" scope and rings on my son's 10/22 where it will be fine for him to practice. Now I can start whittling at the other ideas you've given me. If I manage to bring down the group considerably again, I'll post the results. Thanks a bunch!