308 won't shoot 180 gr. rounds

jsdboy

jsdboy

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Hi All,

Even though it is a hunting rifle, I thought I would post this question to the precision peoples.

I have a new Savage M14 Euro Classic short action in .308 Win.. 22" barrel, rifling twist 1 in 10". Light rig; 7.25 lbs.

It has only 50 rounds through it so far. Have found that it "sprays" 180 gr. factory loads (Federal, Win. And the fancy hunting loads of each) into 4-6 inch groups. sometimes it will put one shot on top of another and the third flies 4" away.

With 150 gr. factory rounds, I can make 3 shot groups from 7/8" to 1.25". All shots are at 100 yds. And i Know most of the error is me, meaning they will go tighter- it is operator error.

So what gives? Are the harmonics for this barrel such that it just will not shoot a heavier round? Do I just make peace with the fact that 150's are it? I have not had a chance to try 165 or 168's yet

Any thoughts?? Thanks for looking.
 
180gr is a little big to be shooting out of a .308 IMO

I only really load 155-168gr bullets in my .308 I wouldn't even consider 180gr for target shooting

after 175gr, which only some twist rates like, is pretty much the limit

at 180gr you are getting into 30-06 territory.

Though I did buy a box of 185gr Lapua hunting bullets that I might try in the .308 for hunting, but I bought the box mainly for use in my 30-06.
 
A 1:10 should stabilize 200 gr bullets, however your light barrel may not shoot them as well as the lighter bullets. As the bullet weight increases so does the felt recoil. There will be those that will argue up and down that the .308's recoil isn't anything to worry about, but with a 7.5 lbs rifle it can be if the stock doesn't fit you properly. If you are getting good groups with 150 gr bullets I would not say your scope is pooched.
With only 50 rounds down it you really haven't tried every kind of 180 gr ammo available, I know this can be expensive but hey the next box of ### brand might be the one that works.
 
keegs said:
Does the second shot fly off and then the third shot fly back in next to the first?
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yes, Although the other way around has happened too. But predominately what you said: #1 on, #2 way off, #3 on.

Mr. Fleury: I think that what you mentioned about the Rem varmint is in line with what Mr. Maynard touched on: a very light barrel. And the little gun kicks like a mule on amphetamines. I had a big ol' BAR in 308 once and it was nothing compared to this one. The rifle fits me good. I'm happy with scope/mounts as the POI doesn't seem to drift.

Thank you all for comments. Looks like i'm gonna have to pull my loading press out of the cabinet:confused:
 
My experience with light barreled hunting guns has been that they are particular to what they shoot, not only bullet weight relative to twist rate alone. Heavy barreled target guns seem much more forgiving. The barrel being the week link, followed by the bedding. That being said your particular problem sounds suspiciously bedding related, perhaps combined with technique. Also with only 50 rounds down range it's barely broken in. If you didn't live on the other side of the country I would certainly load a variety of hand loads for you to try. Barrel fouling could also be a culprit of poor accuracy.
 
Can click here for a spreadsheet that has the greenhill formula for twist. Use "custom" to play with, "Data" pulls from the "Load Data" sheet. The bullet selected in the second formula also populates the ballistics page which I pulled from an online calculator.
 
Twist is fine for 180 Gr - most 308's use 1 in 12 or 1 in 14. Obviously Savage had heavier bullets in mind. (good idea, from my perspective)
Your rifle barrel doesnt like the heavier bullet weight - since its light, it can whip with greater amplitude, as you are finding out. (Heavier barrels are more forgiving as the vibration amplitudes are less.)
If you reload, you can play around with powders and charge weight to alter the barrel residence time.
 
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jsdboy said:
yes, Although the other way around has happened too. But predominately what you said: #1 on, #2 way off, #3 on.
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Get someone to grab your eye piece focus if it's a rapid focus design and have them try and wiggle it up and down while you hold the rifle steady and look through the scope.

I have two friends that the same thing happened as you but one was with any ammo and it would go off over a foot at 100yds and the other buddy when his messed up was only evident when he shot heavier lead. Both burris's.

Might not be the problem but still worth a quick check.
 
keegs said:
Get someone to grab your eye piece focus if it's a rapid focus design and have them try and wiggle it up and down while you hold the rifle steady and look through the scope.

I have two friends that the same thing happened as you but one was with any ammo and it would go off over a foot at 100yds and the other buddy when his messed up was only evident when he shot heavier lead. Both burris's.

Might not be the problem but still worth a quick check.
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Oh Boy! I can hardly wait to get to the range to try that one out. The scope is a new Bushnell "legend" 3 X 9 X 40. Definitly not top of the line. It may not like the bigger bump of the 180's at all

Mr. Hilchey: thanks for the comments. the barrrel appears to be freely floating. I have been doing the obsessive kind of fire three shots, clean, fire, clean etc. then at end of day using butch's bore shine and no blue is coming out. Glass bedding certainly wouldn't hurt though........
 
Well - When you establish that its not the scope, slip a piece of thin cardboard under the forend to give a few pounds of load to the barrel. Then try your 180 grainers....
I wont burden you with the technicals, suffice to say this is what Remington does.
 
You are over cleaning. But you can now look at it as the barrel in now broken in. Fire 3-4 fouling shots before trying to shoot a group. Then don't clean it again until you have another 200 rounds down the barrel.
 
The twist is good for up to 220 grain bullets. I shoot 180s out of my 1:13 all the time.

The standard American target rifle bullet in 1:12 barrels is the Sierra 180 or 190 matchking.

Assuming scope and bedding are ok, try the up pressure on the barrel at the forend. A piece or two of cardbaord from an ammo box is usually enough. A dab of glue will hold the cardboard in place. If this works, the rifle should be bedded with this feature added.

First, bed the action in the usual way. Then make a pair of plastercine "worms" to lay across the inside of the forend, an inch apart, to hold the bedding comound in place. Rough up the wood so it will hold the bedding. Place the worms just behind the cardboard shim. A teaspoon of compound will be enough between the worms. With cardboard shim still in place, bolt the rifle back together. Later, the shim and worms can be removed, and you will have a littlepdto support the barrel, making it stiffer.

I do this to all my light barrel hunting rifles.
 
your twist rate is fine... if all your equipment is fuctioning as it should it may be how deep you're seating bullets...if you're not reloading try a box of Fed Gold Medal Match 175 gr... more important stop cleaning the barrel so often...
 
Ganderite said:
First, bed the action in the usual way. Then make a pair of plastercine "worms" to lay across the inside of the forend, an inch apart, to hold the bedding comound in place. Rough up the wood so it will hold the bedding. Place the worms just behind the cardboard shim. A teaspoon of compound will be enough between the worms. With cardboard shim still in place, bolt the rifle back together. Later, the shim and worms can be removed, and you will have a littlepdto support the barrel, making it stiffer.

I do this to all my light barrel hunting rifles.
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what bedding compound do you prefer/recomend?

And thank you all about the cleaning thing. I haven't had a new rifle in a long time and i have read a lot of stuff about "barrel break in" and was going with that. So yes, first i will allow the barrel to get fowled, then try some 180's, then play with bedding. i guess i had better bring out the long unused loading press since i can't find any 308 anywhere in the area. seems to have been some panic buying going on............
 
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