BulZi wrote:The bullpup is ergonomically great for offhand shooting, because even with a long heavy barrel (22" bull), the center of mass is right above your trigger hand with a 13" LOP. You get to hold the weight in close to your chest, and not way out in front.

I disagree here. More weight farther from a pivot point slows the pivot around that point. Imagine a tightrope walker with a 12 foot balance pole weighing 20lbs or 2ft balance pole weighing 20lbs. The angular pivot speed around the center pivot point (which is basically what offhand shooting wobble is) is much faster for the shorter pole. This is why people have custom silhouette rifles built with longer, heavier barrels instead of short, really fat barrels. It slows down the wobble, resulting in higher scores.

Just a few notes.

I started shooting 3-position smallbore many years ago (sold all that a while back) and I have been shooting 600/1000 yard F-Class and rimfire silhouette for a few years. I learned that it takes some folks a lot more practice and investment (time & money) in developing competitive skills than it does others. Natural talent goes a long way, some folks will never be really good shooters. Good equipment also helps alot. You have to determine how much raw talent you already have and how much time & money you can invest in developing the talent. If you have a very busy career and family life then range time will be limited, hard to expect to be a world class shooter if you only shoot during a few matches.

Some folks have the luxury of being able to afford the finest rifles and scopes on the market and some of us cannot. I shoot a 10-22 and Marlin Model 60 in rimfire because it is what I can afford, I can't possibly swing an Anschutz. I also shoot a Savage action with a custom barrel in LR because I can never be able to afford a RPA or Nesika rig. If I waited to save up enough money to get the best stuff I could never shoot a match. Having said that, I have no ill will towards those who can get the best stuff. I wish them all the luck in the world. I know that I will have a lot more fun shooting what I have and getting as good as I can with it rather than trying to shoot at the highest levels. Basically, a new shooter has to ask himself how competitive should he expect to be with the gear and practice time has access to and if he will be satisfied with that answer.

I also learned that if I get too serious about a sport then I will quit having fun. If I can't have fun then I may as well stay home and paint the garage. Others thrive on being very serious about the sports they shoot whether it's BR, LR HP, or silhouette. That's their personaility and it works for them. Do whichever you are most comfortable with, it's still just a hobby.

Lastly, our little match at the club here is pretty laid back as far what we allow. As long as it's safe we'll let you shoot. If it's outside the rules you won't get to shoot for score or prizes but you'll still have fun. I would imagine that many of the match directors are them same way. Just ask them before hand if it's cool to shoot whatever you have.

JC,
Amen...the only time I have seen a person not allowed to shoot, was over the speed of the ammo, with damage to the targets (high velocity on cast targets), and he was offered free standard velocity ammo, and chose to decline it and not shoot.
I shot mallbore silhouette for 19 years with iron sights, because I could not afford a scope, ended up buying a kids rifle, for the scope, and have since progressed on to several scopes now. Come out and enjoy the fun, and smeel the burning powder, it clears the mind!

Innocent Mary

When you think Hoppies#9 would make a good cologne, beware, you have the fever.

AD9...trust me milk bones do not smell anything like H#9...smelled plenty of that in my youth cleaning all 23 DCM rifles as well as my brothers and mine three times a week. But yes, I have had the addiction to smelling burning gun powder in competition for 38+ years now.

Innocent

"More weight farther from a pivot point slows the pivot around that point. Imagine a tightrope walker with a 12 foot balance pole weighing 20lbs or 2ft balance pole weighing 20lbs. The angular pivot speed around the center pivot point (which is basically what offhand shooting wobble is) is much faster for the shorter pole."

Yeah, I know what a moment of inertia is. You are confusing the moment of inertia with the center of gravity, which is the point I was making. The moment of inertia for my bullpup is also quite good, since most of the weight is either in the very front or the very back (distributed far from the center of gravity) but you don't want to try to hold up a big cantilevered weight far from the center of mass.

Imagine if you had to hold up a 20-lb 20-foot balance pole such that it is aligned with a particular line in 3-space (like a barrel pointing to a target). You can choose to hold it by the first inch, or the middle inch (balance point). Which hold will be easiest with minimal wobble?

People choose longer barrels for a lot of reasons, and people put weight on the muzzle for a lot of reasons. Longer barrels are used with iron sights sometimes just to increase the sight radius, which is a non-issue for scopes and red dots. Sometimes a longer barrel has a particular ballistic effect, either to speed up (or in many cases with longer rimfire barrels, to slow down) the round. Sometimes people want to slow down a swing, but ultimately, what you are talking about (moment of inertia) is no longer the limiting factor. Rather, it is the ability of a shooter to hold a stable line in comfort. Weight helps steady things, but I guarantee that a person can hold a broomstck steadier in the middle than on the end, regardless of length or weight. That is why a javelin thrower holds the javelin near the middle, rather than on the end - impossible to aim from the back or front.

Yes, a longer balance beam will have a larger moment of rotational inertia than a shorter beam of equal weight, but it will be harder, rather than easier, to hold steady from a point far from the balance point.

I love the smeel of gun powder in the morning...it smeels like...

For me it's the Eley primer but really, I can quit anytime I want too...

BulZi wrote:Yes, a longer balance beam will have a larger moment of rotational inertia than a shorter beam of equal weight, but it will be harder, rather than easier, to hold steady from a point far from the balance point.

It will require more strength to hold up, but the linear extension from the end (i.e.- aiming point on a far surface extended through the axis of the pole) will be steadier. This is where we differ in our opinions. I have built my smallbore rifle as light as I reasonably could within my budget (1712 action) and put as much weight in as long a barrel as allowed by the rules. It does slow down the wobble and does fatigue me a bit more over 120+ shot matches due to the weight farther from me. I have also shot a couple rifles with very thick, short barrels that were designed for benchrest. They were much harder to hold steady on a target long enough even though they were approximately 2lbs heavier than my frankenhunter rifle.

With that said, the easiest proof that bullpup rifles are not easier to hold steady offhand is in the fact that there isn't a single one of them in the hands of a top shooter at any of the top matches. These people, who I am not one of, spare no expense in development of gear for this game.

"With that said, the easiest proof that bullpup rifles are not easier to hold steady offhand is in the fact that there isn't a single one of them in the hands of a top shooter at any of the top matches. These people, who I am not one of, spare no expense in development of gear for this game."

Uh, except for the fact that bullpup stocks are not legal due to the requirements about comb height relative to the bore center axis. You can spend all the money you want, but you can't change the rules. That is like saying that a car is slower than a bike, because no one has ever won the Tour de France in a car, and those teams have the money to buy anything. None of the top teams have cars, strictly bicycles.

The whole point of my post is this: An electronic trigger solves the crappy-mushy-trigger problem of the bullpup, but it doesn't solve the rules problem of the bullpup stock layout. That is purely a NRA rules matter, and not due to a technical deficiency on the part of the bullpup. Trigger linkages are such a technical deficiency, but they can be solved

I mainly responded because your analysis of a balance-beam was wrong, physics-wise. You said that a longer balance beam was more stable than a shorter balance beam of equal weight, which is true, due to the larger moment of rotational inertia. However, in either case, the long or short balance beam is being held at the center of mass, which was exactly my point about why a bullpup is comfortable, which you ignored. This is the most relaxed position that offers the most stable grip with the least amount of isometric effort, tremor, fatigue, etc. It is easier to hold an object stable in space by gripping near the center of mass. It is also easier to hold an object stable if it has a large moment of inertia, which is influenced by the mass and the mass distribution. Both statements are true.

You ignored that point, and then you cited a false argument, that no top competitive shooter is using a bullpup. How can they, when several rules of the stock configuration prevent bullpup stocks? If you can't have the cheek above the bore center, and you can't have the scope anywhere other than directly above the bore line, and you can't have a tilt-axis stock, you can't have a bullpup in silhouette competition. It just isn't allowed.

People don't shoot them in silhouette competition, but it is because they are against the rules, not because they have inferior ergonomics, balance, or stability. They have never been a major platform for precision shooting in other disciplines largely because of the poor triggers. The trigger problem can be solved by innovation, but the rules problem can only be solved by regulation changes.

You are ignoring the fact that you are still confusing comfortable/easy with steady. They are not the same. If ease of lifting and comfort resulted in accuracy, we'd all be shooting 4lb guns with 16" pencil thin barrels in silhouette matches. If weight as close as possible to the pivot point (which is NOT either of the hands when shooting a rifle, and is actually close to the center of the upper chest or hips in standing offhand shooting, depending on the model used), we'd all be shooting max weight guns with short, heavy barrels and weight in our stocks. Neither of these is true because neither of them actually work. The fact that it requires less force applied at a given distance from the pivot point to accelerate a shorter mass of a given weight about the pivot point is exactly why the longer barrel results in a steadier offhand shooting. The more mass there is farther from the pivot point, the more force (wobbly offhand shooter input) it takes to accelerate the mass in a given direction at a given rate. Given the same force applied at the pivot point, the larger mass farther from the pivot point will accelerate much more slowly about the pivot point.

According to your logic, a shorter gun of a given weight that would put the center of gravity over the trigger hand is easier to shoot well offhand (i.e.- steadier) than a longer gun of a given weight. In this case, let's take the 8.5lb limit for a smallbore hunter silhouette rifle. With a shorter barrel and weight put in the stock, the center of gravity could easily be moved back to the trigger hand or even farther. It doesn't have to be bullpup configuration. The same center of gravity can be achieved without the comb being higher than the centerline of the bore. Maybe I should chop 10" off my 26" barrel (or even more with a "short barreled rifle" permit!) on my rifle and shove cut-off barrel chunk in the stock to make it easier to shoot offhand and give me a HUGE advantage over all of the other master shooters out there. Umm.. yeah. Why do you think that no one actually does that? Why do you think that guns used for offhand shooting speed events usually have shorter barrels and guns used for slower, more accurate events have longer barrels? It's physics, not poor triggers. Do you really think no one would have put better triggers on short rifles by now if they were actually better? Seriously?

There are lots of shooting games where there is no rule preventing having a comb above the centerline of the bore when shooting offhand. Bullpups don't rule those unless the point of the game is to shoot very quickly at larger, closer targets. Bullpups definitely have their place, as quick-pointing guns that can pack firepower into a smaller package. When it comes to our particular game, where we have lots of time to shoot at small targets at distances that make them difficult to hit, a shorter rifle is only beneficial if the physical dimensions and strength of the shooter require it.

By all means, keep trying to explain to people who do nothing but shoot offhand in matches why you know how to design an offhand rifle better than anyone else. It would be entertaining if not for the risk of new shooters reading it and believing it enough to end up with frustration and regret at spending their time and money the wrong way.

BulZi wrote:".That is like saying that a car is slower than a bike, because no one has ever won the Tour de France in a car,....

Jesse, You gave me a good laugh with this one! Submarines don't have the stamina of runners either. A sub never finished a 5K race....

Jason, we are not building the bullpup for rimfire silhouette. We are building it for ourselves.
The main reason to build it is the basic 10/22 problem of a poor bond between the barrel and receiver.
This is only important when you mount your sights on the receiver as the 10/22 does with scopes.
If you follow 10/22 at all you will see barrel droop mentioned a lot.
When we have them built, you will see the results either here or on Rimfire Central.

I ain't getting it to the WR squared debate since I make, sell, and use heavy lead weight in my AR's.


It does dampen accelerations and attenuate recoil. But, because it helps my AR doesn't mean it makes a bullpup less accurate or harder to shoot.

Regards, Ray

"You are ignoring the fact that you are still confusing comfortable/easy with steady. They are not the same. If ease of lifting and comfort resulted in accuracy, we'd all be shooting 4lb guns with 16" pencil thin barrels in silhouette matches. If weight as close as possible to the pivot point (which is NOT either of the hands when shooting a rifle, and is actually close to the center of the upper chest or hips in standing offhand shooting, depending on the model used), we'd all be shooting max weight guns with short, heavy barrels and weight in our stocks. Neither of these is true because neither of them actually work. The fact that it requires less force applied at a given distance from the pivot point to accelerate a shorter mass of a given weight about the pivot point is exactly why the longer barrel results in a steadier offhand shooting. The more mass there is farther from the pivot point, the more force (wobbly offhand shooter input) it takes to accelerate the mass in a given direction at a given rate. Given the same force applied at the pivot point, the larger mass farther from the pivot point will accelerate much more slowly about the pivot point."

Wrong. I didn't say any of that. There are several variables in the design of a gun that are inter-related, and not independent. There are optimal and suboptimal ways for a gun designer to use the weight allowed (either by the rules, or other constraints like shooter strength or shooter preference for a carried weapon). A 4lb gun with a pencil thin barrel would not be ideal, simply because it wouldn't have the optimum weight and inertia to be steady. Reduction to absurdity works both ways. No one shoots 50lb guns that are 20 feet long offhand either, both due to reasons of practicality and rules. If it wasn't against the rules, someone might perhaps try (Schwarzenegger). God knows that heavy guns, long or short, perform better from the bench. Also, remember, I said that a long barrel affects sight radius and of course ballistics. There are plenty of reasons to want a long barrel. I said that, and you ignored it. If it were allowed and feasible, I'd want a barrel that goes all the way out to the bullseye - Other design constraints take over, weight, portability, practicality, cost, ballistics. At a certain point, comfort and ease of shooting are absolutely a factor.

"According to your logic, a shorter gun of a given weight that would put the center of gravity over the trigger hand is easier to shoot well offhand (i.e.- steadier) than a longer gun of a given weight. In this case, let's take the 8.5lb limit for a smallbore hunter silhouette rifle. With a shorter barrel and weight put in the stock, the center of gravity could easily be moved back to the trigger hand or even farther. It doesn't have to be bullpup configuration. The same center of gravity can be achieved without the comb being higher than the centerline of the bore. Maybe I should chop 10" off my 26" barrel (or even more with a "short barreled rifle" permit!) on my rifle and shove cut-off barrel chunk in the stock to make it easier to shoot offhand and give me a HUGE advantage over all of the other master shooters out there. Umm.. yeah. Why do you think that no one actually does that?"

Again, you are completely missing my point and ignoring my concessions of yours. You might choose not to chop off 10 inches of barrel purely for reasons of ballistic effects and sight radius, to name two. However, people do choose to put weight into the butts of stocks up to the rule limits all the time. They use lead slugs, wedges, and cores. It is partially to alter the center of gravity, partly to inertially damp recoil, and partly because that's where the space is (which is why people also put lead weights into the foreend stock too). No one EVER hangs a lead weight from the very muzzle end of a rifle to get up to the weight limit while increasing the moment of inertia to the utmost. Again, there are lots of reasons why that would be a bad idea. On a bullseye pistol, people tend to hang weight under the barrel, which has to do with minimizing the flip during recoil, by changing the moment of inertia. Often times, these barrel weights make it point worse, but recoil better. However, there are only so many places to put weight on those pistols and keep it inside the box.

"Why do you think that guns used for offhand shooting speed events usually have shorter barrels and guns used for slower, more accurate events have longer barrels? It's physics, not poor triggers. Do you really think no one would have put better triggers on short rifles by now if they were actually better? Seriously?"

Again, I concede that longer barrels have higher inherent accuracy potential due to pure ballistics. When barrel length is extremely limited by other design constraints (like in bullseye pistol, where the pistol has to fit into a small box) people do put a lot more emphasis on trigger performance than they do on rifle triggers. If I were shooting at 100 yards, I would choose a fairly low-end rifle over a $2500 olympic pistol any day, rules allowing. The longer barrel and the better pointing stability of a stocked firearm will beat barrel quality in this case. I would choose a 50lb bench rest rifle over either one, if I could shoot it from a bench. The mass distribution of a rifle is what it is for many many inter-dependent reasons. The barrel cannot be made arbitrarily light and accurate at the same time.

"There are lots of shooting games where there is no rule preventing having a comb above the centerline of the bore when shooting offhand. Bullpups don't rule those unless the point of the game is to shoot very quickly at larger, closer targets. Bullpups definitely have their place, as quick-pointing guns that can pack firepower into a smaller package. When it comes to our particular game, where we have lots of time to shoot at small targets at distances that make them difficult to hit, a shorter rifle is only beneficial if the physical dimensions and strength of the shooter require it."

We will never know, because bullpups aren't allowed in your particular game, for whatever reason. Bullpups don't rule ANY shooting competition, because they have a lot of weaknesses (cost, complexity, triggers, safety, noise, fumes in the eye, ambidexterity) and they aren't available as an accurate rules-compliant factory rifle from a company like Anschutz. This isn't an argument to say a bullpup is better for any particular competitive event, rules and practicality aside. I also concede that a bullpup design necessarily (without using axis-shifting optics) moves the sighting axis farther from the bore axis, which is bad.

This is merely to say that you confused moment of inertia with center of gravity in your original post, and to point out that the rules about stock appearance discourage innovation in firearm layout, even though many military firearms designers think the added complexity of the bullpup is worth the effort for other reasons (which may or may not include either accuracy or pointing stability). There are lots of rifles optimized for offhand accuracy which don't look like hunting rifles and wouldn't be allowed in many classes of NRA silhouette. That is fine. Perhaps, what is needed is a class of rifle that is unrestricted except for caliber, max weight, and that the overall length must be between 26" and 28" - A rules class like that would shift innovation towards the best shooting weapon that fits in a compact envelope.

"By all means, keep trying to explain to people who do nothing but shoot offhand in matches why you know how to design an offhand rifle better than anyone else. It would be entertaining if not for the risk of new shooters reading it and believing it enough to end up with frustration and regret at spending their time and money the wrong way."

I am not saying I know how to design rifles better for any purpose, competition or not. I just know how to make a bullpup with a good trigger, and that is something people have tried to do for a long time before. However, most shooters don't design weapons, they choose them based on what is available. Manufacturers of competition weapons design for rules compliance. Therefore, it is the rules which influence the designs which are seen on the firing line. No one can even go down this road in this event because of the rules. With no economic reason to do so, and plenty of reasons not to, the designer can't really explore it.

Try an experiment that has nothing to do with the expense and difficulty of designing and building a gun. Take a broomstick, and tape a laser pointer to it. Hang a five-lb sack of flour from the muzzle, and point it at a far wall. Then, move the 5lb's back, until it is between your two hands, near your chest. Examine the difference in pointing stability. The stick with the sack of flour has a greater moment of inertia, but the stick with the sack of flour near the center of gravity points more stably. This experiment shows that varying weight distribution (which changes the moment of inertia and center of mass) will alter pointing ergonomics. It is an accurate experiment to settle the initial point of contention, and not some BS argument about balance beams (which are, incidentally, your analogy, and are, incidentally, held near the center of mass). Convince yourself with an experiment that muzzle-heavy mass distributions do not point more stably. That was your original assertion.

I don't know everything about firearms design, but I know physics and biophysics. I also know that you are ignoring my points in making yours. You can increase the moment of inertia by shifting weight forward and backward without moving the center of mass at all. Such an object would have better pointing stability than a sphere (most compact mass distribution) AND it would still be balanced. The shooter is both the source and the solution for wobble, because we use dynamic muscle input to steady the aim.

Your original point was that an object with muzzle-heavy mass distribution and larger moment of inertia points more stably than a center-balanced object, which ignores that you can adjust the moment of inertia without changing the center of gravity by shifting weight both forward and rearward.

No weapon design that I have ever seen purposely places mass near the muzzle for reasons of pointing stability. Look at where the center of mass is on all of these non-bullpup rifles: http://jga.anschuetz-sport.com/index.ph ... &sprache=1

Not one has a big weight placed at the muzzle. In weapons that do have a forward mass distribution, it isn't because that distribution lends pointing stability, it is because some other design constraint necessitates it.

Easy enough to reply to the above novel with a small paragraph. In your broomstick example, if I held the gun more like a rifle and had the head of it under my armpit and held with both hands, the laser pointer was indeed much steadier against the far wall with the weight (6lb laptop in backpack, but close enough to your 5lb sack of flour) out at the far end than it was with it between my hands. I couldn't hold it there for as long, but it was definitely steadier with it there. I had two non-shooter coworkers try it to verify. Second, there are lots of rifles with weight purposefully added out near the end of the barrel, including very many of the standard class rifles in use in silhouette competition. Many of the smallbore variety have adjustable weighting systems on barrel shrouds that are extensions of the barrels themselves to be farther away from the shooter while retaining the shorter barrel travel time of a shorter barrel. Just because you don't know about them doesn't mean they don't exist. Don't let that discourage you, though.

Edit: Adding URL to specific example of barrel weighting system for Anchutz rifle designed specifically to stabilize

http://www.champchoice.com/prod-ANSCHUT ... -2760.aspx?