Nosler Accubond Long Range problem

[elkaholic]

Guys, check your lr ab pills for eccentric tips. I've found one already that isn't good for much more than a fireforming load as the tip isn't centered perfectly. My pills aren't factory seconds either......

update... ran the whole box over the table and had three that didn't pass muster/ too crooked. 3% bent tips is a bit high for a rather high dollar pill when even the 140 bt blems I got from shooters a while back had 0% bent tips.

That doesn't do much for accuracy! It seems unlikely though that since you only found three that it was what caused your problem?......Rich

 

[bigngreen]

I'm far more worried about high velocity, oh crap close range shots than long range, I hope I'm wrong but just looking at the cavity and tip combo I'm thinking these could ruin a meat cutters day. Bonding or not it looks like that nose will go of like a grenade at close range!

 

[elkaholic]

I'm far more worried about high velocity, oh crap close range shots than long range, I hope I'm wrong but just looking at the cavity and tip combo I'm thinking these could ruin a meat cutters day. Bonding or not it looks like that nose will go of like a grenade at close range!

I plan on finding out before the weekend is over!......Rich
i just visually checked the 5 bullets that I have and one of the five has a noticeable fold in the jacket from the ballistic tip down the ogive of the jacket for about 1/8" or so. This happens quite often when you run a bullet through the point forming die when you have a void in the end of the jacket (i.e. no lead to support the jacket) I suspect they probably get quite a few of those during production but cull them out during quality control.This is ONE of the areas I mentioned earlier concerning multiple steps in making a bullet The more of them, the better the chance for accuracy decline...Rich

 

[Fiftydriver]

Guys, check your lr ab pills for eccentric tips. I've found one already that isn't good for much more than a fireforming load as the tip isn't centered perfectly. My pills aren't factory seconds either......

update... ran the whole box over the table and had three that didn't pass muster/ too crooked. 3% bent tips is a bit high for a rather high dollar pill when even the 140 bt blems I got from shooters a while back had 0% bent tips.

I have tested bullets with out of center tips to see how they effected down range accuracy. What caused me to test this is because when I was testing the first batch of prototype bullets from the old Wildcat Bullet company, I got a shipment of 265 gr Aluminum Tipped RBBTs. Richard told me that the tips on many of these bullets were not concentric but to use them for velocity testing just to see what they would do and to make sure they did not come apart in flight.

In testing, I sorted bullets out so that I had a batch of bullets that were all within 0.001" in baring surface length. Then I sorted two batches out, one that had tip run out less then 0.002 thou and one lot that had tip run outs of at least 0.008" and many were over 0.010" run out. Rolling them across the bench really showed how out of center they were.

Set up at 1000 yards and shot three shot groups. The bullets that had extreme run out did shoot larger groups. For five, three shot groups, the "Bad" run out bullets averaged 0.960 moa ctc. The nearly perfect run out bullets averaged 0.823 moa ctc.

Now on any given day, I can not say for sure that this difference was not ME instead of the bullets. In my testing, the heavier the bullet and the larger the caliber, the less critical it is to have the tip perfectly centered.

I also believe that the mass of the bullet will cause the bullet to rotate around its center of mass and because the tip is VERY light in comparision, it does not have enough mass to really effect the stability of the bullet.

I also tested some barnes TTSX bullets in 7mm, 30 cal and 338 as they often have tips that have more run out then you would expect from a commercial bullet maker. Again, in all those tests, I could not produce results that proved the bullets that had the most run out caused accuracy to drop off. The polymer tips are EXTREMELY light and it seems that they do not have enough mass to cause any accuracy problems that would effect us as long range BIG GAME hunters.

In all honesty, these results do surprise me as I do not see how a tip leading the way that is wobbling around does not really effect accuracy to a great deal but all one has to do is look at the meplat on a SMK to see that they can be extremely inconsistent with one side being much longer then the other and while uniforming the meplat on these bullets can help with making BC more consistant, accuracy usually is not effected to any noticeable degree.

 

[Fiftydriver]

I'm far more worried about high velocity, oh crap close range shots than long range, I hope I'm wrong but just looking at the cavity and tip combo I'm thinking these could ruin a meat cutters day. Bonding or not it looks like that nose will go of like a grenade at close range!

Looking at the bullet design with that huge cavity behind the tip, I would predict explosive expansion when driven over 3000 fps and when impacts are hard and at ranges under 200 yards.

I think for deer sized targets there would be no real issues as most bullets will get the job done but on a heavy target such as elk, you could easily run into problems in my opinion. That is all it is for sure but I think I would probably stick with the conventional Accubond if there is a chance for a close range, hard impact.

 

[elkaholic]

I have tested bullets with out of center tips to see how they effected down range accuracy. What caused me to test this is because when I was testing the first batch of prototype bullets from the old Wildcat Bullet company, I got a shipment of 265 gr Aluminum Tipped RBBTs. Richard told me that the tips on many of these bullets were not concentric but to use them for velocity testing just to see what they would do and to make sure they did not come apart in flight.

In testing, I sorted bullets out so that I had a batch of bullets that were all within 0.001" in baring surface length. Then I sorted two batches out, one that had tip run out less then 0.002 thou and one lot that had tip run outs of at least 0.008" and many were over 0.010" run out. Rolling them across the bench really showed how out of center they were.

Set up at 1000 yards and shot three shot groups. The bullets that had extreme run out did shoot larger groups. For five, three shot groups, the "Bad" run out bullets averaged 0.960 moa ctc. The nearly perfect run out bullets averaged 0.823 moa ctc.

Now on any given day, I can not say for sure that this difference was not ME instead of the bullets. In my testing, the heavier the bullet and the larger the caliber, the less critical it is to have the tip perfectly centered.

I also believe that the mass of the bullet will cause the bullet to rotate around its center of mass and because the tip is VERY light in comparision, it does not have enough mass to really effect the stability of the bullet.

I also tested some barnes TTSX bullets in 7mm, 30 cal and 338 as they often have tips that have more run out then you would expect from a commercial bullet maker. Again, in all those tests, I could not produce results that proved the bullets that had the most run out caused accuracy to drop off. The polymer tips are EXTREMELY light and it seems that they do not have enough mass to cause any accuracy problems that would effect us as long range BIG GAME hunters.

In all honesty, these results do surprise me as I do not see how a tip leading the way that is wobbling around does not really effect accuracy to a great deal but all one has to do is look at the meplat on a SMK to see that they can be extremely inconsistent with one side being much longer then the other and while uniforming the meplat on these bullets can help with making BC more consistant, accuracy usually is not effected to any noticeable degree.

Kirby........IMO you are correct that the light tip has some affect but not a lot. The base of the bullet (rudder) is a far different story. Try putting a nick on the base sometime and see what happens.......Rich

 

[Fiftydriver]

Kirby........IMO you are correct that the light tip has some affect but not a lot. The base of the bullet (rudder) is a far different story. Try putting a nick on the base sometime and see what happens.......Rich

Yep, one would not think it works that way but it sure does. That is why boattail bullets are more difficult to produce and shoot extremely well then flat base bullets. I have found that most custom bullets that have accuracy problems can be tracked down to the boattail or bullet body dimensions.

Even bullet weight has proven to be not all that critical. I have shot 7mm bullets that varied by as much as 3-4 grains that still would shoot under 3/4 moa at 1/2 mile ranges as long as baring surface lengths were consistant and boattails consistant as well.

 

[elkaholic]

Yep, one would not think it works that way but it sure does. That is why boattail bullets are more difficult to produce and shoot extremely well then flat base bullets. I have found that most custom bullets that have accuracy problems can be tracked down to the boattail or bullet body dimensions.

Even bullet weight has proven to be not all that critical. I have shot 7mm bullets that varied by as much as 3-4 grains that still would shoot under 3/4 moa at 1/2 mile ranges as long as baring surface lengths were consistant and boattails consistant as well.

You are on the money with the bullet weight too. Some of the things we fiddle with to be perfectionists amount to little and things we often ignore, can be a big deal. When I first started making bullets, I thought more weight forward was probably a good thing (like the tip on an arrow) keeping the thing pointing forward. I soon changed my mind! We all weigh powder charges right down to a kernal of powder and yet, there are many other variables in developing a round that are FAR more important. Go figure.
I have had some trouble with tips in the past and also have conducted tests. I concluded pretty much as you have that it is something to consider, but not as much as you think. What I did learn was don't polish the bullets very long in a tumbler, etc. after they are complete with tips. It is amazing what that vibration will do! .........Rich

 

[Lefty7mmstw]

I doubt it'll kill a load to have slightly crooked tips on the pills, but it'll get you laughed at by anyone who can see worth a hoot. It also is a sign of quality control issues, so where else does the pill have issues....

As to the accuracy of these pills, the 7mm 150 alr survived the stw's today with good groups. At 200 yards 77 grains rl25 and the 150 alr went into a 2" group with mostly vertical in my rifle, mostly from a sandbag reset. The next group fired with my rifle was 80 grains rl25 and the 150 alr, of which the first three went into 1.1" at 200, and the next two went wild from mirage.

The ced chrono wouldn't pick up the bullets in the rainy overcast so I didn't get speeds. It was cool and rainy with zero wind so the mirage was bad within three shots nearly every group.

As to my dad's rifle, he simply pulled some 150 grain pills he had loaded with 78.5 rl25 and stuffed the alr's in replacing the original pill. The first group was about 3" ( 4 shot)at 200 yards with two definate groups, before and after a sandbag reset both handing in 1" or less double taps a couple inches apart. The second group was a 1.2" three shot group with the fourth called off as the mirage went nuts ( I didn't bother to fire).

I will play with these pills more in my rifle as they seem to be about as accurate as the 7mm 140gr nos tipped pills are, but I need better weather to really wring them out.

 

[gamehawker]

Roy and Lefty,

How far off the lands are you loading these ABLRs?

Thanks!

 

[Lefty7mmstw]

Roy and Lefty,

How far off the lands are you loading these ABLRs?

Thanks!

Loading to mag length... at 3.650". I'm not single feeding these so why load longer.

 

[Engineering101]

Lefty,

Pardon the dumb question but how are you getting mirage on a rainy overcast day where there isn't even enough light to trigger the chrono? Does it not take some sun to have mirage? (By the way, the IR skycreens for the CED work well and allow shooting in any light or lack thereof.)

 

[Lefty7mmstw]

Lefty,

Pardon the dumb question but how are you getting mirage on a rainy overcast day where there isn't even enough light to trigger the chrono? Does it not take some sun to have mirage? (By the way, the IR skycreens for the CED work well and allow shooting in any light or lack thereof.)

barrel heat mirage mainly... haze from the humidity too

 

[Lefty7mmstw]

Lefty,

Pardon the dumb question but how are you getting mirage on a rainy overcast day where there isn't even enough light to trigger the chrono? Does it not take some sun to have mirage? (By the way, the IR skycreens for the CED work well and allow shooting in any light or lack thereof.)

I have the infared screens for my ced, but don't have a powder source for them at present... I need to get my hands back on the oehler. Much better chrono.