Your pointy bullets and their flight

[Steve Blair]

If your LR gun is shooting .1 or less at 100 I'd like to borrow it for 2015.

No, seriously I would like to see the targets.

[br]
Don't have 6BR targets but here's a tuner setting session from my .300 WSM F-Class rifle. Fired from a wooden bench, 230 Hybrids at ~2865 fps. Target bullets don't get much pointier and longer than 230 Hybrids. When validating the #5 setting, the rifle agged five 5-shot groups @ .202". I think it could be improved with a solid, concrete bench but this is what I have available. The second target is what the rifle and load will do at 1000. That is twenty-two shots in 7.642", fired in a match from prone with rest on the ground and rear bag on my shooting mat. [br]
A 6BR or Dasher can improve this due to less significant recoil problems. I agree with Jim, If your 6BR isn't agging in the ones or better, look for the problem.

 

[johara1]

If your LR gun is shooting .1 or less at 100 I'd like to borrow it for 2015.

No, seriously I would like to see the targets.

You PM me your cell # and i will send you some and if you can agg. in 2" at a 1000 what do you think it's doing at 100……. jim

 

[johara1]

Oughtta take it to some short range shoots and see how it fares. Unlimited class needs some smaller aggs.

Why, i think you should come to a long range match ……. and see how you fare……….. we need humor ……… jim

 

[Raythemanroe]

If your LR gun is shooting .1 or less at 100 I'd like to borrow it for 2015.

No, seriously I would like to see the targets.

You PM me your cell # and i will send you some and if you can agg. in 2" at a 1000 what do you think it's doing at 100……. jim

Ray

 

[michaelnel]

This is unlikely to end well.

 

[jerrysharrett]

"Don't believe everything you read on the Internet". wasn't that Will Rogers??

 

[jerrysharrett]

Donovan, got it, thanks.

 

[Toby Bradshaw]

This is unlikely to end well.

As with many unproductive discussions, that's because apples are being compared with oranges. I assume that Jerry is talking about agging in the 1s across a multi-day all-conditions short-range tournament. There are plenty of tournaments where a grand agg starts with a 1 for quite some distance down the list. Jim is giving the numbers for his world record aggs, and I'm betting that his 100-yard tests agging in the 1s are not multi-day all-conditions shooting.

If we compare apples to apples using records (see below), it's pretty clear that short-range benchrest records require much smaller groups and aggs when expressed in MOA. There are many confounding factors, of course. E.g., conditions have a much greater effect in long-range BR, can't see bullet holes at 1K, much better flagging at short-range shoots, there are vastly more competitors and venues in short-range BR, and the list goes on. ANY of these records are impressive accomplishments and nobody is well served by suggesting otherwise.

IBS Light Gun 1Kyd 6-match agg = 3.072"
IBS Light gun 1Kyd small group = 1.397"

Short range bag gun 5-5 aggs (MOA):
IBS 5-5 agg 100yd: 0.1364
IBS 5-5 agg 200yd: 0.1602
IBS 5-5 agg 300yd: 0.1828

IBS 100yd group: 0.051" (NBRSA record 0.0077")
IBS 200yd group: 0.091" (NBRSA record 0.075")
IBS 300yd group: 0.240" (NBRSA record 0.149")

Of note is that ALL of the short-range group records are below 0.050 MOA, equivalent to a half-inch group at 1Kyd (not saying that a half-inch group at 1K is as easy as a 0.050" at 100yd). The record short-range aggs are roughly half the 1K record agg in MOA.

It seems to me that there is virtually no overlap between the top competitors in short-range and long-range BR. I would guess that the top shooters in either discipline could BECOME top shooters in the other discipline, because the mental game is very similar in both. Clearly both disciplines require great equipment and the ability to read/adjust to conditions.

 

[Raythemanroe]

This is unlikely to end well.

It seems to me that there is virtually no overlap between the top competitors in short-range and long-range BR. I would guess that the top shooters in either discipline could BECOME top shooters in the other discipline, because the mental game is very similar in both. Clearly both disciplines require great equipment and the ability to read/adjust to conditions.

I'm not sure I agree 100%, Point blank shooters seem to have a bit more relaxed reloading regimen then LR benchrest. I'm sure Ohara didn't set his records dumping powder, probably weighed to better then a Milligram resolution. Following the thread I would assume that sorting longer VLD type bullets is much more important.

Also your agg ratio would be: 0.1364 to 3.072, 0.051 to 1.397 Record for record



Ray

 

[Toby Bradshaw]

This is unlikely to end well.

It seems to me that there is virtually no overlap between the top competitors in short-range and long-range BR. I would guess that the top shooters in either discipline could BECOME top shooters in the other discipline, because the mental game is very similar in both. Clearly both disciplines require great equipment and the ability to read/adjust to conditions.

I'm not sure I agree 100%, Point blank shooters seem to have a bit more relaxed reloading regimen then LR benchrest.

And long-range BR shooters don't (can't, because of limited flag info) read and hold for conditions as well as short-range shooters.

But I still maintain that the key elements -- shooting for aggs instead of single groups, reading the effects of loads and conditions on the targets, testing many barrels to find those that are competitive, strategies honed by lots and lots of practice under match conditions -- are the same.

 

[Dusty Stevens]

Oughtta take it to some short range shoots and see how it fares. Unlimited class needs some smaller aggs.

Why, i think you should come to a long range match ……. and see how you fare……….. we need humor ……… jim

Howd you do last year?

 

[Raythemanroe]

This is unlikely to end well.

It seems to me that there is virtually no overlap between the top competitors in short-range and long-range BR. I would guess that the top shooters in either discipline could BECOME top shooters in the other discipline, because the mental game is very similar in both. Clearly both disciplines require great equipment and the ability to read/adjust to conditions.

I'm not sure I agree 100%, Point blank shooters seem to have a bit more relaxed reloading regimen then LR benchrest.

And long-range BR shooters don't (can't, because of limited flag info) read and hold for conditions as well as short-range shooters.

You couldn't read that many flags and get your shots off before conditions changed..

Wonder what the ratio of mirage effect at point blank vs 1k is?


Ray

 

[Toby Bradshaw]

You couldn't read that many flags and get your shots off before conditions changed..

The point of flags is not just to know when a condition is stable, but to know where to hold when it changes. Many top shooters don't use sighters to know where to hold -- they (not me) can tell where to hold just by looking at the flags and the position of the previous record shot. Using record shots as sighters is a huge help, but of course it only works if you can see bullet holes at the distance you're shooting.

Wonder what the ratio of mirage effect at point blank vs 1k is?

Angular displacement by mirage is constant, so absolute displacement is directly proportional to distance.

 

[holstil]

I take from this discussion that a point on which to improve on is not so much the long, pointed or boat tailed, but the materials and processes required with regard to LR bullets.
Sooo, does anybody care to discuss other methods or concepts to (some degree feasibly) build a better mouse trap? Cast or partial cast of different materials, different swaging tools/methods or combining methods? Thinking of solids, spinning is a great way to remove/prevent error and variance, can that be expanded on? Spun jackets cast cores? Wait, I said feasible didn't I? Some probably wouldn't want to indulge their secrets.

I'm certain there are other qualified opinions from those reading and posting but thank you for your posts on the subject Bryan and Eric. Obviously much respect afforded.

It's very hard to pass up information coming from the likes of Sam, J O'hara, Larry, James Coffey and many other shooters who have put the proof on paper.
Don't shoot much but I enjoy testing what I read and hear when I can.
Thanks to all for conversation.

Larry, How'd the match go?

 

[goodi]

The origin of this post was a statement questioning the possibility of achieving consistent accuracy from pointed VLD projectiles at around 3000fps.

Opinions and experience related to this statement was then sought.

Subsequently, a number of informative responses have been provided from various sources.

As others have rightly pointed out, in terms of precision long range 1000yd BR Mr James O’Hara has managed to achieve standards of accuracy, presently unmatched in the LRBR fraternity.

IMHO, the numerous world 1000yd BR records he has set with pointy VLD projectiles at around 3000fps should ensure that any questions or comments from James should be given appropriate emphasis and consideration and should not be taken lightly.

I have no doubt, that in addition to Mr O’Hara numerous other 1000yd BR competitors strive to tune their rifles to an accuracy standard which enables 100yd groups of around 0.1 inches or less.

For the most part, this discussion has been beneficial as it has centred on theoretical and practical aspects of projectile design and manufacture and the actual associated standards of achievable accuracy

In my opinion, attempts to introduce and draw comparisons between LRBR and SRBR to this topic are not related to the discussion.

cheers
dave goodridge

 

[jerrysharrett]

Guys, my primary reason for starting this thread was to solicit ideas for a bullet design that would be more consistent than the
currently used super-points like LD's and such.

Is there a design of shape or a methodology of bullet forming that is more improved than what is currently used?

A statement has been made more than once in this thread that since most records set at 1K were set with VLD's that there should be no doubt that VLD's are the only way to go. Problem with this logic is that VLD's are the ONLY shape being used.

Not only is a better design possible a better methodology for bullet making might be possible given more thought. For example, the nose point is currently being swaged and the resultant shape is at the mercy of how that particular jacket decides to fold. How about if that ogive point spun or rolled like the aerial bombs in use since around WW I?

I am certain that if a super accurate measuring system were used to scan the nose profile of current bullets that, within a given lot, they would not all be alike, Maybe only off by a few thousands but off non the less.

Litz or some aero physics expert, is the ogive profile the most efficient for the high BC's we like? The ogive profile has been assumed to be the way to go, but is there a better design?

And so on...no where in my intention did I solicit any suggestions about loading, or whatever else, simply expecting to get LR shooter grey matter in gear.

Anyhoo, thanks for any and all your thoughts about whatever.

.

 

[JRS]

How about a triple radius ogive Jerry

 

[Bryan Litz Ballistics]

There are other shapes for projectile noses which have been designed for minimizing drag: http://en.wikipedia.org/wiki/Nose_cone_design

Rather than being sections of circular arcs like most bullet ogives, these designs are mathematically defined to be optimal according to supersonic aerodynamics. If you look closely at these optimal nose shapes like the Sears-Haack and the Von Karmen, they're very similar to a conventional secant ogive with an Rt/R ratio close to 0.5 (VLD).

Another problem when considering these 'optimal' nose shapes is that you can derive an 'optimal' shape for a specific Mach number, but the nose won't be optimal off that condition. In other words, the 'best' shape at 3000 fps is not also the best shape at 1800 fps. For aircraft and cruise missiles which fly at constant speed, you can design an optimal shape for a flight condition. But for bullets, the speed sweeps such a wide range that any nose design is a compromise between the expected high and low speed.

Scroll to the bottom of the Wiki link above to see a chart of what Mach numbers the various nose shapes are optimal.

-Bryan

 

[jerrysharrett]

There are other shapes for projectile noses which have been designed for minimizing drag: http://en.wikipedia.org/wiki/Nose_cone_design

Rather than being sections of circular arcs like most bullet ogives, these designs are mathematically defined to be optimal according to supersonic aerodynamics. If you look closely at these optimal nose shapes like the Sears-Haack and the Von Karmen, they're very similar to a conventional secant ogive with an Rt/R ratio close to 0.5 (VLD).

Another problem when considering these 'optimal' nose shapes is that you can derive an 'optimal' shape for a specific Mach number, but the nose won't be optimal off that condition. In other words, the 'best' shape at 3000 fps is not also the best shape at 1800 fps. For aircraft and cruise missiles which fly at constant speed, you can design an optimal shape for a flight condition. But for bullets, the speed sweeps such a wide range that any nose design is a compromise between the expected high and low speed.

Scroll to the bottom of the Wiki link above to see a chart of what Mach numbers the various nose shapes are optimal.

-Bryan

But what nose shape and generation methodology could we introduce that we could produce bullets that the noses would not be precise duplications of each other. I still have the feeling that;

1) the noses we swage are not precise duplicates of each other.

2) in using these unequal shapes and a seating punch, like the Wilson for example, where that punch contacts the nose curve, leaves a variation between its contact point and the curve, down below, where this curve contacts the chamber leade. (did I really screw up my attempt to describe this situation?)

Probably in using a hard jam or a significant jump this situation would not be an issue, but, in the situation of slightly away or just touching to slight jam, the variations in the condition 2 above might be the culprit that causes some inaccuracy???

.

 

[Steve Blair]

But what nose shape and generation methodology could we introduce that we could produce bullets that the noses would be precise duplications of each other.

[br]
Nothing made by man or God is a precise duplicate of anything else.