Poor results past 100yrds with 160gr NP .277 bullets!

[Why not?]

It is not uncommon to see guys at the range shoot small groups at 100 yards, yet shoot groups just like yours at 300. There are several reasons, and I have seen it over and over again.

My own personal standard for big game hunting rifles is a magazine-full from the bench into five inches on a target at 300 meters on our silhouette range. That's 328 yards, one and a half Minutes Of Angle.

Think about it this way: all five shots hit within two and a half inches of the aiming point at 328 yards, more than accurate enough for myself hunting.

Not a slight towards anyone at all, but you would be amazed at how many guys cannot do that consistently with their favourite hunting rifle. I have been disappointed several times myself.

Ted

 

[444shooter]

Only loss is I have to track down some 150's. No LGS has much in the way of reloading supplies.

Anyone local want to trade a couple boxes?

Got quite a few, but far away in AB

 

[Nipigon Jack]

Looks like X Reload has the 160 grain partitions in stock.
$65.00/50

 

[Ganderite]

Twist: If a bullet is too long or too slow it will yaw badly or tumble. You will see this clearly at 100 yards. If the load groups with nice round holes at 100, you are good to go. The bullet will gain stability as it moves down range, because RPM remains about the same, but as it slows, the air becomes less dense.


All you have done is document and prove (again) that 100 yard groups mean nothing in terms of down range performance. If you are a 100 yard plinker, your load is great.

If you want accurate ammo to 300, then you have to do your load development at 300. This is because of the interaction of velocity variations with barrel harmonics. 100 is too close to see it, but 300 shows it clearly.

Take your existing load and shoot it again at 300 yards, shooting 2 increments hotter and 3 increments of 0.3gr milder. 3 of each should be enough.

One of those loads should group well.

Nothing wrong with the twist or the bullet.

 

[medvedqc]

for some that will be more than enough for some ... seems your rifle did not like the COAL powder primer and bullet.

 

[freddyfour]

It is not uncommon to see guys at the range shoot small groups at 100 yards, yet shoot groups just like yours at 300. There are several reasons, and I have seen it over and over again.

My own personal standard for big game hunting rifles is a magazine-full from the bench into five inches on a target at 300 meters on our silhouette range. That's 328 yards, one and a half Minutes Of Angle.

Think about it this way: all five shots hit within two and a half inches of the aiming point at 328 yards, more than accurate enough for myself hunting.

Not a slight towards anyone at all, but you would be amazed at how many guys cannot do that consistently with their favourite hunting rifle. I have been disappointed several times myself.

Ted

My 300m target has only one shot on paper, point of aim is the top left target.

The 200m group looks more like what you describe for a 300m group.

The 130gr AB running at 3200fps with 63gr RL22 shoots 3-3.5" at 200m out of this rifle.

 

[MRP]

If u get 1 inch at 100 u should get 3 at 300 plus a little bit depending on the scope power. Low 4x not as sharp as 9x. Scope parallax is most likely to be the answer. What scope is it, check the parallax range, most are 100 to 150 yards some as low as 75. The more yards out past the parallax zero the more shooter has to be doing his part. If u ever shot a bow its about nock points, u must be the same every time.

 

[Suther]

If u get 1 inch at 100 u should get 3 at 300 plus a little bit depending on the scope power. Low 4x not as sharp as 9x. Scope parallax is most likely to be the answer. What scope is it, check the parallax range, most are 100 to 150 yards some as low as 75. The more yards out past the parallax zero the more shooter has to be doing his part. If u ever shot a bow its about nock points, u must be the same every time.

The shooters position behind the scope would have to be horrible for this to be a parallax issue - in fact I'm not sure you can get that far out of alignment and still see through the tube. Chances of this being a parallax issue seems highly unlikely.

 

[Why not?]

If u get 1 inch at 100 u should get 3 at 300 plus a little bit depending on the scope power.....

This is what most people think, but is not the case at all. Ganderite has posted a quick explanation why.

Twist: If a bullet is too long or too slow it will yaw badly or tumble. You will see this clearly at 100 yards. If the load groups with nice round holes at 100, you are good to go. The bullet will gain stability as it moves down range, because RPM remains about the same, but as it slows, the air becomes less dense.


All you have done is document and prove (again) that 100 yard groups mean nothing in terms of down range performance. If you are a 100 yard plinker, your load is great.

If you want accurate ammo to 300, then you have to do your load development at 300. This is because of the interaction of velocity variations with barrel harmonics. 100 is too close to see it, but 300 shows it clearly.

Take your existing load and shoot it again at 300 yards, shooting 2 increments hotter and 3 increments of 0.3gr milder. 3 of each should be enough.

One of those loads should group well.

Nothing wrong with the twist or the bullet.

This has been proven many times by shooters all over the world by actually shooting at longer ranges after printing small groups at 100, and is what I was referring to in my earlier post.

It is not uncommon to see guys at the range shoot small groups at 100 yards, yet shoot groups just like yours at 300. There are several reasons, and I have seen it over and over again.

My own personal standard for big game hunting rifles is a magazine-full from the bench into five inches on a target at 300 meters on our silhouette range. That's 328 yards, one and a half Minutes Of Angle.

Think about it this way: all five shots hit within two and a half inches of the aiming point at 328 yards, more than accurate enough for myself hunting.

Not a slight towards anyone at all, but you would be amazed at how many guys cannot do that consistently with their favourite hunting rifle. I have been disappointed several times myself.

Ted

Ted

 

[Ganderite]

Parallax can give a 1 minute error quite easily. At 300 yards that would add 3" to whatever the group would have been.

My concern is the "If u get 1 inch at 100 u should get 3 at 300 "

Not necessarily. The reverse may be true. If you have a good load that gets 3" at 300 yards, it should be 1" at 100.

But if there are velocity variations, they don't have much effect on the 100 yard group. And the way the barrel harmonics can either mask or amplify these variations (positive or negative compensation) do not show up at 100, but do show up at 300 (and beyond).

The bottom line is that if the OP cars about 300 yard performance, he has to do his load development there. 100 yards does not mean anything, except that the rifle works well.

 

[freddyfour]

This is what most people think, but is not the case at all. Ganderite has posted a quick explanation why.




This has been proven many times by shooters all over the world by actually shooting at longer ranges after printing small groups at 100, and is what I was referring to in my earlier post.



Ted

Parallax can give a 1 minute error quite easily. At 300 yards that would add 3" to whatever the group would have been.

My concern is the "If u get 1 inch at 100 u should get 3 at 300 "

Not necessarily. The reverse may be true. If you have a good load that gets 3" at 300 yards, it should be 1" at 100.

But if there are velocity variations, they don't have much effect on the 100 yard group. And the way the barrel harmonics can either mask or amplify these variations (positive or negative compensation) do not show up at 100, but do show up at 300 (and beyond).

The bottom line is that if the OP cars about 300 yard performance, he has to do his load development there. 100 yards does not mean anything, except that the rifle works well.

Always appreciate when you guys chime in! I have about 85pcs of 160 NP left so I will mess around till she is all gone. I have never had this happen with any rifle I have loaded for, mind you I have only been loading for about 7yrs. Was pretty disappointed after printing reasonable groups at a 100.

 

[MRP]

I'll have to test the 1 minute thing some time, when the 4' of snow is gone.