Range Report Bullet questions.....need your advice

[Blackrifle1]

Hi everyone. I purchased a Savage FCP-K 10 (.308) with a Vortex Viper PST 4-16x50 scope to shoot outdoors from 250-700 yrds. I really like the rifle and scope- NO issues with either of these. I also purchased some Federal Premium .308 175 gr Sierra Matchking BTHP gold medal match ammo, mainly because this is the only ammo they had and I could find for this rifle. I'm no expert on ammo so I value your opinions.

I was shooting at the range with a couple buddies and my one buddy noticed the ammo tips were all irregular (uneven and offset holes in the point) As we started looking closer at all the ammo, they were all like this. The sad thing is that one of my buddies was shooting an AK with Wolf 7.62 hollow point ammo (yes Wolf) and the tips were actually perfect!- waaaaay nicer than the federal premium ammo. How can this be?

I contacted federal about the situation, sent them pictures (pictures from my iPhone, they aren't perfect pictures, but you can see the irregularities) and below is the response I got from them - which doesn't make sense to me...I never mentioned anything about hunting.....what do you think??

From Federal...."Thank you for submitting these pictures. This is a Boat Tail Hollow Point designed for superior accuracy, not designed as a hunting load. Irregularities in the hollow point will not affect accuracy at all. If you have further questions please contact Sierra."

What are your thoughts?

 

[melloyello]

Perfectly normal. That's how those bullets come when you buy them. Match bullets are more about bullet concentricity. The irregular meplats won't make a difference in flight. They will however cause cartridge OAL differences when measuring from bullet tip and not bullet ogive.

 

[rduckwor]

AT the ranges you are shooting, these variation will be a minor issue. However, Sierra is infamous for their irregular meplats. Truly serious long range shooters will trim and uniform these bullets if they stick to Sierra for their shooting. Most people use different bullet manufacturers for LR and ELR shooting (Berger JLK, etc).

Good Luck.

 

[thrusty]

I'm going to assume the reason why they mentioned hunting ammo is that they get your question ALOT and some people will assume that hollow points are ALWAYS made for expansion in hunting applications.....in other words, they assumed that you're asking whether the non-uniform tips will effect expansion upon impact.

I don't have any documentation for why the use of hollow points in LR bullets...however some will say they are used in order make the bullets uniform in weight...some will say the hollow point is there to provide surface area for expanding gasses...I'd like a good source if anyone knows of the exact reason for hollow points in LR applications....maybe Lapua can chime in.

 

[damoncali]

Totally normal. It's just the way they're made and it doesn't matter much.

 

[Blackrifle1]

ok- thanks for the replies guys. I just find it a little strange that a "premium" bullet that is supposed to be used for competition shooting has irregularities in the tip. I'm no expert, but my guess was (still is) that this could effect the rounds precision to be on target, why else do professional shooters check their tips for burs and stuff and clean them up?

 

[damoncali]

It's counter intuitive, but the irregularity of the tip has almost no impact on accuracy. Recently, people have started cleaning them up by "pointing" them (running the bullets into a die to shrink the diameter of the tip), or trimming them (cutting them back more precisely), or both. Pointing can decrease drag, trimming will increase drag, and doing both might be a wash. In any case, it's an advanced handloading practice for long ranges with custom rifles. There are many things that matter a lot more.

 

[ksthomas]

...some will say the hollow point is there to provide surface area for expanding gasses...I'd like a good source if anyone knows of the exact reason for hollow points in LR applications....maybe Lapua can chime in.

Well if that's not an open door invitation, I don't know what is! Sure thing. The manufacture of hollow points in match bullets isn't really a design feature, as much as just an end result of the manufacturing process. They don't "try" to make them hollow points, that's just what the process produces. The noses are closed up as much as they possibly can, but there is always a bit of an opening left. And as Thrusty already mentioned, just because it's a hollow point, doesn't automatically mean that the bullet was designed to expand. The SMK line is used in US combat sniper rounds (such as the M118LR) legally, since it does not violate the Hague or Geneva Accords. It's a non-expanding design which routinely behaves exactly like an FMJ on impact, as verified by the Letterman Army Wound Ballistics Lab and Col. Marty Fackler some years back.

The conventional FMJ or FMJBT design is, in essence, made "backwards" during production. You start with a flat-based jacket, and form a point in the center of that flat base. This results in a rather sharply pointed jacket, open at what will ultimately become the base. Once this ogive and meplat is formed, a lead (or steel) core is inserted, and the base closed or boat tailed. Final sizing and the addition of a cannelure (on those bullets that have them) completes the bullet. To do this rather extensive reforming at the ogive, most FMJ jackets are massively thick, compared to similar hunting or target bullets. They need to be to accommodate this much reforming. Unfortunately, the thicker the jacket, the harder it is to keep it concentric. Thinner jackets are much easier to maintain concentricity, but don't stand up to such drastic forming. The solution is to make the bullet from the other end. That is, stamp a boat tail on the flat base, insert a lead core, and then close the end with the open mouth into the ogive. In doing so, you reduce much of the stress on the jacket, and can therefore use a thinner jacket to begin with. This thinner jacket, being easier to draw and maintain concentricity on, usually makes for a much more accurate finished bullet. The problem here is that you have to be able to get the formed bullet back out of the die, and that's what keep you from closing the nose down too far. There's a pin hole at the very tip of the die, and a very thin knock out rod that pushes the formed bullet back out on the upstoke of the press. The strength of this knock out rod is the limiting factor. If the material at the tip of the bullet actually pushes into the knock out hole, you get what Sierra calls "flaring" (a straight portion of material, actually ahead of the ogive). This adds tremendous strain to the punch, and will usually end up bending (like a pretzel) them. This in turn leads to the press trying to seat a second bullet on top of the first (which is still in the die) and generally creates a hell of a mess. The tips have to be kept far enough back from that knockout hole (only talking a few thou here) to avoid this, which means you can't fully close the tips. This gives the resultant hollowpoint format we see in the finished product. It has nothing to do with air flow in flight, expansion on impact, or any of the dozen other ideas I've seen expressed about them. It's a manufacturing anomaly, pure and simple.

 

[ksthomas]

ok- thanks for the replies guys. I just find it a little strange that a "premium" bullet that is supposed to be used for competition shooting has irregularities in the tip. I'm no expert, but my guess was (still is) that this could effect the rounds precision to be on target, why else do professional shooters check their tips for burs and stuff and clean them up?

Blackrifle1,

There's virtually no effect whatsoever on the "precision" of these bullets, or how they'll perform on target. While everyone gets concerned about the tips (meplats), it's actually the least important area of he entire bullet in terms of most accuracy questions. The meplat, if you look at the bullet from the nose on, is actually located as close to the center of gravity as it can possibly be. Irregularities in the jacket's concentricity, which place the problem as far from that CG as possible, are what magnifies in flight and creates serious accuracy problems. As I explained in the previous post, reducing the jacket thickness, and maintaining that concentricity, is what that hollow point design is all about. The critical end of the bullet, is the base, particularly the break of a boat tail where the bearing surface transitions to the BT angle. Any sort of damage or deformity in this area will also cause serious accuracy problems.

 

[thrusty]

Well if that's not an open door invitation, I don't know what is! Sure thing. The manufacture of hollow points in match bullets isn't really a design feature, as much as just an end result of the manufacturing process. They don't "try" to make them hollow points, that's just what the process produces. The noses are closed up as much as they possibly can, but there is always a bit of an opening left. And as Thrusty already mentioned, just because it's a hollow point, doesn't automatically mean that the bullet was designed to expand. The SMK line is used in US combat sniper rounds (such as the M118LR) legally, since it does not violate the Hague or Geneva Accords. It's a non-expanding design which routinely behaves exactly like an FMJ on impact, as verified by the Letterman Army Wound Ballistics Lab and Col. Marty Fackler some years back.

The conventional FMJ or FMJBT design is, in essence, made "backwards" during production. You start with a flat-based jacket, and form a point in the center of that flat base. This results in a rather sharply pointed jacket, open at what will ultimately become the base. Once this ogive and meplat is formed, a lead (or steel) core is inserted, and the base closed or boat tailed. Final sizing and the addition of a cannelure (on those bullets that have them) completes the bullet. To do this rather extensive reforming at the ogive, most FMJ jackets are massively thick, compared to similar hunting or target bullets. They need to be to accommodate this much reforming. Unfortunately, the thicker the jacket, the harder it is to keep it concentric. Thinner jackets are much easier to maintain concentricity, but don't stand up to such drastic forming. The solution is to make the bullet from the other end. That is, stamp a boat tail on the flat base, insert a lead core, and then close the end with the open mouth into the ogive. In doing so, you reduce much of the stress on the jacket, and can therefore use a thinner jacket to begin with. This thinner jacket, being easier to draw and maintain concentricity on, usually makes for a much more accurate finished bullet. The problem here is that you have to be able to get the formed bullet back out of the die, and that's what keep you from closing the nose down too far. There's a pin hole at the very tip of the die, and a very thin knock out rod that pushes the formed bullet back out on the upstoke of the press. The strength of this knock out rod is the limiting factor. If the material at the tip of the bullet actually pushes into the knock out hole, you get what Sierra calls "flaring" (a straight portion of material, actually ahead of the ogive). This adds tremendous strain to the punch, and will usually end up bending (like a pretzel) them. This in turn leads to the press trying to seat a second bullet on top of the first (which is still in the die) and generally creates a hell of a mess. The tips have to be kept far enough back from that knockout hole (only talking a few thou here) to avoid this, which means you can't fully close the tips. This gives the resultant hollowpoint format we see in the finished product. It has nothing to do with air flow in flight, expansion on impact, or any of the dozen other ideas I've seen expressed about them. It's a manufacturing anomaly, pure and simple.

Fantastic explanation. Thank you for the schooling!

I had no clue of the actual process and that precision/target bullets are made from the tail up to the nose - In other words, the hollow points are just byproducts of the manufacturing process.

 

[ksthomas]

Not quite all, but the vast majority these days. Lapua makes some of the very few true "match" quality FMJ designs, specifically our D46 and Lock Base designs that are truly competitive against the HPBT designs. Even at that, we also offer the Scenar line (HPBT designs), and they are generally our most accurate. Many of the FMJs on the market today are abysmally bad, and yet guys still want to shoot them in their military style rifles, "because that's what the military uses." The military uses these designs because International Laws of Land Warfare require them, not because it's a nifty design. Pretty easy to see when even the military goes to something like the M118LR when they really need substantial accuracy. for the vast majority of troops, the typical 2.5-3 MOA FMJs are just fine.

When the 173 grain FMJBT was the standard projectile for our military 30-06 ammo, the arsenals like Frankford used to continually monitor the accuracy of the bullets coming off the lines. When a particularly accurate lot was identified, it was put aside for producing "Match" ammunition. If a more accurate lot was identified, the older lot was replaced or supplanted by the newer lot. This cycle was continued throughout the year. Ultimately, when the arsenal began production of that year's Match ammo, they had (literally) the best of the best bullets already identified and ready to go. When the 173 was replaced with the lighter 152/150/147 grain FMJs we've used since, the problem of producing really good FMJs had to be dealt with, and it was tough. This is at least part of the problem with the original M72 and M118 ammo; the bullets weren't usually as good as the selected lots chosen from hundreds of different lots of (again, literally) billions of bullets. I guess you could say that this inconsistency is what drove the military to seek out a solution that ultimately resulted in the use of the HPBT designs we see in the modern M118LR.

 

[Blackrifle1]

Blackrifle1,

There's virtually no effect whatsoever on the "precision" of these bullets, or how they'll perform on target. While everyone gets concerned about the tips (meplats), it's actually the least important area of he entire bullet in terms of most accuracy questions. The meplat, if you look at the bullet from the nose on, is actually located as close to the center of gravity as it can possibly be. Irregularities in the jacket's concentricity, which place the problem as far from that CG as possible, are what magnifies in flight and creates serious accuracy problems. As I explained in the previous post, reducing the jacket thickness, and maintaining that concentricity, is what that hollow point design is all about. The critical end of the bullet, is the base, particularly the break of a boat tail where the bearing surface transitions to the BT angle. Any sort of damage or deformity in this area will also cause serious accuracy problems.

Thank you for the explanation, and your expertise on this subject - just seems like it goes against the norm of any type of object going through the air at speed.

 

[damoncali]

Thank you for the explanation, and your expertise on this subject - just seems like it goes against the norm of any type of object going through the air at speed.

The faster they go, the weirder it gets. It's all part of the fun.

 

[ksthomas]

Blackrifle1,

It would seem that way, but part of the problem is that you're looking at the "deformation" as it's static; it's not when it's in flight. Say that's a 77 grain bullet, fired at 2750 fps in an AR with a 1x8" twist. While that slight angle across the meplat is noticeable when you're sitting there looking at it, in flight, that little sucker is spinning at about 4,125 revolutions per second on it's way downrange. Now picture an F-16 with it's front end damaged equally badly as the angled meplat on the bullets in question; makes a whole different picture when the F-16 is flying Mach 2, and NOT rotating around its CG. There, in trying to track straight, the damage would have an entirely different (and very severe) effect on the flight of the aircraft/projectile.

As I mentioned earlier, that meplat is sitting right on the CG of the bullet as you look at it, head on. The problems, such as an offset CG caused by jacket wall concentricity issues, are exacerbated or magnified the further they get from that CG. With any discrepancy on the meplat being so close to the CG, you're not really dealing with anything to magnify, if you see what I'm getting at. Bryan Litz can do a far better job explaining this in his books, but then, he's got a whole book to work with! You get the idea, though, don't you? Add to that the fact that the boundary layer of compressed air around the bullet in flight essentially prevents "contact" between the two, and you can see where the whole concept becomes just a minor anomaly, and not a major factor in the bigger scheme of things.

 

[Rapidrob]

In Dr. Mann's Book " A Bullets Flight", he clearly noted and states you can do darn near anything to the nose of the bullet and it makes very little difference where the bullet will go. Do ANYTHING to the base of the bullet and it will not fly straight.
Over my 50 years of shooting I can attest to this as fact. I have fired at long range bullets with damaged tips that flew straight. I have also fired old surplus bullets where the base of the bullet was slightly rusted away, or the lead core was cut at an angle to the base. Neither would come close to hitting the target.

 

[damoncali]

Another way to put it is that defects (like a void or inclusion) on the centerline of the bullet cannot unbalance it because they're already on the axis of rotation. Think about putting a wheel weight right smack in the middle of the axle- it's not going to do squat as far as balance goes! A defect on the bearing surface will have a large impact because it unbalances the bullet as much as is possible. Since the meplat is (hopefully!) at the center, it doesn't matter much - you can mangle it pretty good. There is probably a good deal more going on with regards to the fluid dynamics, but that's getting out of my area of knowledge.

 

[ksthomas]

Very good analogy, and a ridiculously simple illustration of that point. Couldn't have said it any plainer that this.