Oval Bullet Holes

M

Mark IV

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I am shooting a Rem. 700 rifle, heavy barrel, .308 with Sierra 168 gr. Match King bullets, 43.5 grains of 4064 powder with Win large rifle (not mag.) primers. MV is 2640 according to chronograph. Rifle groups .4 to .8 at 100 yards shooting 5 shot groups.

Tried rifle at 1,000 yards and noticed that bullet holes are oval rather than round. Any thoughts on what causes this and its effect on accuracy? :D
 
I am shooting a Rem. 700 rifle, heavy barrel, .308 with Sierra 168 gr. Match King bullets, 43.5 grains of 4064 powder with Win large rifle (not mag.) primers. MV is 2640 according to chronograph. Rifle groups .4 to .8 at 100 yards shooting 5 shot groups.

Tried rifle at 1,000 yards and noticed that bullet holes are oval rather than round. Any thoughts on what causes this and its effect on accuracy? :D

switch to the 155 or 175 grain bulets and it should stop. The 168 grain bullets were designed for shorter distances. Good luck, Ron Tilley
 
The 168s are your problem. If you want to keep shooting the 168s, you need to run them to at least 2,700 to keep them supersonic at 1K. Otherwise, switch to either the 175 which is fine at 2,550+ or Lapua or Berger 155, and crank them up to 2,800+ and they will stay supersonic at 1K.

JeffVN
 
Gentlemen, thanks for the help. I will try the 175 grain bullets.
:p
 
Do you know what twist that barrel is? Some of these guys may already have guessed, and certainly it can't hurt to go to a 175. You might try going up a little farther to a 185 or 190. That will just depend on the rifle I guess.

The oval holes basically mean the bullet's out of gas. It will probably not do well in much wind even if you pick up 50 fps, but will certainly do better, and will let you have some fun in good conditions, but that 50 fps or so will most likely need to be found one way or another.

Given good conditions, you can still shoot a pretty nice group that way, but it's really rare.
 
The barrel twist is 1 in 12. I will load some 175 grain bullets up to a reasonably high velosity that groups well at 500 yards and see how they do at 1,000. :eek:
 
Agreed, abandon the 168s for the .308 at long ranges.

The 175 SMK starts out slower than the 168 SMK, but retain velocity better due to better BC and stay supersonic at distances well beyond the 168. The 155 Scenars have a BC approximately equal to that of the 175 SMK, but can be started at 150-200 fps faster,, and so they too stay stable at longer ranges.

Even my 20" M700 LTR with 1:12 twist does fine with FGMM 175s out to (at least) 1,200.

Exactly when the 168s go trans-sonic and yaw depends on air density (density altitude).

Here are some hits on steel at about 1,150 - can you guess which are 168 SMKs?
 

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Mark Just how oval are you talking here because all bullets at 1000yd are coming in at a angle not straight in like at short range most are peaking at 600 yds and dropping from there so the hole will look oval---- some more that others ! just a idea .
 
You can go as high as a 190 bullet in that rifle. Now, I should clarify that there can be some 190's that won't work in a 12 twist because of their shape. But, if you stick to typical match bullets, the 190's should all work well.

You will most likely find that less velocity and more weight is what's going to work best for you. Try a 185 or 190 and try to get 2950 fps from them as a starting place. That should get you in the ball park for good accuracy. These weights in 30cal are very common in 1K competition. Someone here might also chime in and give some advice on a desired minimum velocity for the 187 BIB's. That's a flat base bullet which is used a lot in 1KBR. I personally don't have experience with them, but I've shot 185's and 190's in almost all my guns at one time or another. When everythings working, they can be a great combo.

Just recently I shot a really nice practice group with 210's at 2740fps. Not that I'd recommend that, but, they can work at speeds slower than what's commonly accepted. It just depends on Mother Nature.
 
Phil,

What do you normally shoot the 210's at..... 2950?

BALLISTICALLY I can't see any reason 2750 wouldn't be comparable, if it aggs better..... Real world I bet the drift difference is lost in the noise and so what if your WHOLE GROUP forms an inch further over......


al
 
Guys - I think that trying to drive 210 grain bullets to 2900 fps out of a .308 would not be wise. In looking at my latest Sierra reloading manual, that's something best left to a .300 Win Mag, not a .308 Win. :confused:
 
As to the question above about how big are the ovals, they are approximately two calibers wide. I have several other rifles that I shoot at this range, including 6mm, .338 and even an old Swiss Schmidt-Rubin 7.5 x 55mm that all produce round holes in targets at 1,000 yards.

Thanks for the help.
 
Phil,

What do you normally shoot the 210's at..... 2950?

BALLISTICALLY I can't see any reason 2750 wouldn't be comparable, if it aggs better..... Real world I bet the drift difference is lost in the noise and so what if your WHOLE GROUP forms an inch further over......


al
Well honestly Al, I'm not willing to give that inch as each one in our game costs you an average of >3 points. No thanks.

No I don't think I've ever sent a 210 at 2950. Rarely do I even approach 2900 and doubt seriously I've ever sent one at 29.

While books and programs might say that wind drift numbers are comparable the real world says different. Wind does not go in one direction only and at each turn the bullet will loose energy. There's no free lunch. In each swirl of air, there's energy loss. When people say to me (as a referee), "I've never lost one of these, I'm not even pushing them". All I can do is think, "yea... well maybe you oughta".

Shoot 210s at 2750 at Williamsport and believe me yer gonna get annihilated. Them folks'll beat you like a rented mule.
 
Well honestly Al, I'm not willing to give that inch as each one in our game costs you an average of >3 points. No thanks.

No I don't think I've ever sent a 210 at 2950. Rarely do I even approach 2900 and doubt seriously I've ever sent one at 29.

While books and programs might say that wind drift numbers are comparable the real world says different. Wind does not go in one direction only and at each turn the bullet will loose energy. There's no free lunch. In each swirl of air, there's energy loss. When people say to me (as a referee), "I've never lost one of these, I'm not even pushing them". All I can do is think, "yea... well maybe you oughta".

Shoot 210s at 2750 at Williamsport and believe me yer gonna get annihilated. Them folks'll beat you like a rented mule.




So you're telling me that you shoot at 2850??? And that shooting at 2750 you'll get annihilated?

al


And BTW, you're not "giving up an inch"...... the difference in drift has absolutely no bearing on how you set your holdoff........
 
Oval holes

If you ever sat behind someone shooting 168 smk and really watched the trace you'll know why they make "oval" holes in the target. :eek:
 
So you're telling me that you shoot at 2850??? And that shooting at 2750 you'll get annihilated?

al


And BTW, you're not "giving up an inch"...... the difference in drift has absolutely no bearing on how you set your holdoff........

Yep, that's exactly what I'm tell'n ya.

And, yes, you are giving up an inch. I don't care how far they drift, only how far they CHANGE drift with the change in wind direction. When that happens, the bullet at 2750 moves MILES farther than the one at 2850. 2950 would be nicer but in a WSM, I can't get them to go that fast accurately, so I choose this particular tradeoff in speed vs accuracy. When it get's windy here, I get killed, and I don't mean just a little bit. I've gotten my guns to shoot a little better in the wind this year than they did last year, but still no where near as well as some of the other good guns here. When it get's windy, the Weatherby's, WinMag's and 68's just have that little bit more snot that you need. But, they do burn more powder and so on.

In my experience, best accuracy with a 210 Berger runs in the range of 2800-2950. In that same range, they work worst to best in the wind, respectively. Go into the 2700's, and they open up. Go too fast, they also open up.

Just chalk it up to "my opinion".
 
Hmmmm, interesting.

Thanks for understanding the question and for the clarification. I'm out of my depth here, very little practical experience, and am relying on what the charts tell me is the difference of 100fps............ I've never experienced the 100fps making "miles" of difference. I just backed my 600yd loads down 150fps and can see no difference in drift.

But you add the caveat "opening up" above AND below your selected velocity.... am I to presume that you might also get creamed with the faster load? In other words is this an artifact purely of velocity??? Or perhaps something else?


al
 
Its still an Accuracy Game

Get your very best accuracy and let the big dog run....:D
 
Al,

I'm not trying to convince you of anything. My opinion is, any bullet will have a velocity range where they work, regardless of what cartridge they're sent out of, ignoring barrel length of course becuase in our situation in 1K, there's generally not much variation within a caliber (bullet dia).

In the case of the 210 Berger at 1K, yes, if you send them too slow, they won't shoot. Send them too fast, they again won't shoot. I say too slow is 2800 and too fast is 2950. My idea that there's a low and high speed isn't some secret or just a tale I dreamt up. Scores of shooters know that you need to find the speed for a bullet.

Anyone who's shot a few ranges that vary will tell you that some ranges, while they get wind, are very consistant. You can shoot groups in a 30mph wind because it's one direction and basically doesn't change. You can also score well in that wind. Not nearly all ranges are like that. Wind is rarely consistant here. Shooting over rolling hills and or deep valleys causes tons of vertical. Add that to swirling wind making windage changes and what you get is bullets that won't make it to the target where they would get there if shot at another range. Believe what you like. My opinion is above.
 
Uh, Phil, do we get to take back all of Charles Bailey's wood? IBS SOTY, etc.?

As I remember, CB shot them about 3,250. I'll allow it was a 36+ inch barrel.
 
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