.308 LAPUA Palma brass

[Bart B.]

Originally Posted by hounddawg

so basically a well tuned load as far as powder choice/powder charge/seating depth and primer selection does the same thing a tuner does.

No. If that were true, nobody would use tuners to make their best handloads more accurate.

If one's handloads have less than a 5 fps extreme spread, a tuner could reduce vertical spread a few SOA or more. All barrels that shoot the same small velocity spread won't have the same vibration properties.

[hounddawg]

No. If that were true, nobody would use tuners to make their best handloads more accurate.

maybe they don't have the patience or ability to can't get their ES/SD's down by load tuning. If you are in consistent single digits for SD and low teens for ES I don't see much of a purpose

[Unclenick]

By adding mass at the muzzle, the tuner slows the overall rate of bending in muzzle deflection. That causes a flat spot to be wider, so load error either in charge weight or due to change in temperature has less effect. In other words, it makes the sweet spot wider, which can be an advantage in some conditions.

[Bart B.]

Originally Posted by hounddawg

If you are in consistent single digits for SD and low teens for ES I don't see much of a purpose

How many seconds of angle is the vertical spread of identical 308 Winchester .500 G1 BC bullets impact at 1000 yards with a 10 fps muzzle velocity extreme spread averaging 2600 fps out the muzzle at the same angle up from the horizontal?

What would the spread be if all bullets left at an angle that well compensated for the outer 80% of that drop (caused by the faster and slower muzzle velocities beyond SD) for each bullet?

[hounddawg]

By adding mass at the muzzle, the tuner slows the overall rate of bending in muzzle deflection. That causes a flat spot to be wider, so load error either in charge weight or due to change in temperature has less effect. In other words, it makes the sweet spot wider, which can be an advantage in some conditions

now that makes good sense, thanks

I knew a guy who was a very competitive rimfire and competed in 300 and 600 centerfire BR that made a rig with orings and neodymium magnets that he was experimenting with on one of his centerfire rifles. Unfortunately he passed a couple of years ago and I have no idea whether his idea worked. I have a nice selection of magnets and O rings, might do some playing to see what I can accomplish. I might be able to convince myself to have my next barrel threaded for a real tuner.

I am pretty sure I can hillbilly engineer something that will accomplish the same thing that one of those adjustable barrel dampening points like the one I linked to a couple of posts back. I might try an experiment with this summer. I checked a couple of rifles and a nylon zip tie is the perfect thickness to put between the barrel and the stock. Easily adjusted by loosening a action screw and using the depth rod on a caliper

[Bart B.]

Originally Posted by hounddawg

I am pretty sure I can hillbilly engineer something that will accomplish the same thing that one of those adjustable barrel dampening points like the one I linked to a couple of posts back. I might try an experiment with this summer. I checked a couple of rifles and a nylon zip tie is the perfect thickness to put between the barrel and the stock. Easily adjusted by loosening a action screw and using the depth rod on a caliper

Remington tried such a device on their 40X target rifles. Two angled screws at the fore end tip, one at 4:30 o'clock and one at 7:30. All it did was change the pressure on one or both touch points as the stock fore end bent from varying external forces. Only totally free floating barrels whip, wiggle and vibrate 100% consistently from shot to shot.

[hounddawg]

Only totally free floating barrels whip, wiggle and vibrate 100% consistently from shot to shot.

so it is said, but then there is a lot of things that are said that are questionable. I like to find out for myself

[Bart B.]

Originally Posted by Unclenick

By adding mass at the muzzle, the tuner slows the overall rate of bending in muzzle deflection. That causes a flat spot to be wider, so load error either in charge weight or due to change in temperature has less effect. In other words, it makes the sweet spot wider, which can be an advantage in some conditions.

Well stated. Thanks.

[Bart B.]

Originally Posted by hounddawg

so it is said, but then there is a lot of things that are said that are questionable. I like to find out for myself

Here's a variable that prevents the most accurate rifle shooting the most accurate ammo into one hole groups:

What direction and how much the hand held rifle's bore axis moves after the primer fires and where it points as the bullet leaves.

[hounddawg]

What direction and how much the hand held rifle's bore axis moves after the primer fires and where it points as the bullet leaves

There is about a million and one things if truth be told. Last practice session I dug out my old shooting coat that I used in High Power but had never bothered with in F class. It threw my entire natural position off so bad my groups looked like they had been shot with a 12 gage. I stripped it off and went back to my sweatshirt and the groups immediately tightened.

I was planning on playing with one of my CZ's Friday but 15 mph winds are forecast so if I do it will just be for wind reading practice, no testing

[reynolds357]

Originally Posted by Bart B.

Remington tried such a device on their 40X target rifles. Two angled screws at the fore end tip, one at 4:30 o'clock and one at 7:30. All it did was change the pressure on one or both touch points as the stock fore end bent from varying external forces. Only totally free floating barrels whip, wiggle and vibrate 100% consistently from shot to shot.

I would like to see that experiment repeated with a heavy Aluminum stock.

[Bart B.]

Originally Posted by reynolds357

I would like to see that experiment repeated with a heavy Aluminum stock.

Any external force on the barrel that is repeatable from shot to shot will produce repeatable barrel vibration frequencies, directions and amplitude for all shots. M1 and M14 service rifles properly rebuilt have 2 to 3 dozen pounds of pull down force at the stock fore end ferrule. Best accuracy was with new cases handloaded with commercial match bullets. 2/3rds MOA at 600 yards was easy.

But they are twice as susceptible to throwing wild shots way off call near MOA when slung up in prone or sitting compared to bolt action rifles with totally free floating barrels. Happens when changing how the rifle's held or sling's adjusted. Windage zeros were a half to one MOA different from off-hand without the sling.

If the heavy aluminium stocked rifle weight is more than about 13 pounds, it won't be held very steady in field positions without artificial support.

[hounddawg]

common sense tells me that for a rifle with a forend touching the barrel that when slung up and variance in the force applied to the sling would cause various amounts if force/flex on the barrel. Angle of exit would be affected depending on the lateral force exerted from the sling tension. I have seen my heartbeat bounce the sight/scope when slung up on bad days. A free floated barrel would not be affected by the slings force on the stock. On a rifle shot from the bench with the forward stop and a light hold the pressure would be exactly the same each time

[Bart B.]

Originally Posted by hounddawg

A free floated barrel would not be affected by the slings force on the stock.

Yes it would. The whole rifle moves in recoil before the bullet leaves the barrel. This is one reason why several people shooting the same rifle (barrel free floated) and ammo have different zeros on the sights. It's called "hot gunning" several people in a team match.

Been there, done that; won the team match.

[hounddawg]

Yes it would. The whole rifle moves in recoil before the bullet leaves the barrel

No kidding. I was talking specifically about a sling and the amount of force on the pressure point

[Bart B.]

https://royalsocietypublishing.org/d...052#d1631807e1

The above was published over a century ago.

I have always seen the scope reticle bounce and wiggle on target. Heartbeats expand and contract muscles which moves the bones supporting the rifle. Nobody holds rifles perfectly still. One third MOA is about as small an area us live humans can keep the line of sight inside of.

As the barreled action is held by the stock, any external force on the stock effects the barrel's movement while bullets go through the barrel. Slung up in prone, a free floated barrel will string shots horizontally as the slung arm's elbow is moved sideways.on the ground. Easily observed shooting 22 rimfire ammo at 50 yards.

[Unclenick]

There is no position shooting that doesn't affect POI. On the other hand, I assume position shooting does not detune a load. That is, the load that shoots best off the bench in a floating barrel gun will normally be the one the position shooter finds best, regardless of what new recoil moments his position and contact points introduce.

Personally, I've always had a problem with a slippery right shoulder in prone. When I fire the 300-yard rapid-fire prone string in a match, I always have to put about 2 MOA of right windage onto a 30 cal rifle, as the butt of the stock moves slightly to the right when the gun fires. 1 MOA with the AR. I leave that windage in place for prone slow-fire.

For sitting rapid that follows standing offhand, I always have to take two MOA of elevation off. But that applies to all rifles I shoot with a 6:00 hold, so I think it has to do with how my brain handles the greater wobble of the standing offhand position rather than having much to do with recoil moments. I suppose the new rules will let me prove that to myself with an optical sight and a center hold.

[hounddawg]

It would be interesting to test with a bipod, shoot 20 rounds from prone and 20 rounds from a bench with a bipod. Then 20 from a rest to see if POI changes.

I need to change my length of pull when adding a jacket it seems and when I removed the jacket my POI went down a full three minutes but it tightened the groups up. I am thinking of ordering a thinner recoil pad and trying the jacket with the pad, easier than hacking off a half inch of stock. I have been rereading Jim Owens books the last couple of weeks and he really stresses having a consistent position.

[Bart B.]

Originally Posted by hounddawg

It would be interesting to test with a bipod, shoot 20 rounds from prone and 20 rounds from a bench with a bipod. Then 20 from a rest to see if POI changes.

I need to change my length of pull when adding a jacket it seems and when I removed the jacket my POI went down a full three minutes but it tightened the groups up. I am thinking of ordering a thinner recoil pad and trying the jacket with the pad, easier than hacking off a half inch of stock. I have been rereading Jim Owens books the last couple of weeks and he really stresses having a consistent position.

I've shot the same stuff with the rifle on bags atop a bench with rifle held 3 different ways, on one or two bags in prone with and without a sling and slung up in prone with a sling without artificial support. Zeros had a 2 MOA plus horizontal spread, 1 MOA vertical spread.

A friend had tested his rifle clamped in a free recoiling accuracy cradle at 600 yard shooting several 10-shot groups under 1.5 inch: 0.25 MOA. He won the 600 yard prone aggregate at the nationals shooting three 20-shot matches keeping all 60 record shots inside 12 inches

Nobody has put 20 consecutive record shots twice in a row inside 1 MOA with a high power rifle slung up in prone. Last time that was done with a 22 rimfire at 100 yards was about 45 years ago.

[Unclenick]

Originally Posted by Hounddawg

I have been rereading Jim Owens books the last couple of weeks, and he really stresses having a consistent position.

Those books are full of practical advice. I bought a couple of them on Commercial Row long ago, then got the rest when Jim Owen established his web site. I use his sight adjustment strategy in matches. I once started a match in the standing offhand phase by putting three 9's in a row at about 7:00. I didn't touch the sights between them because that's where I called them. Then I remembered Owen's advice to make a half correction, then another half correction if needed. All the rest were 10's and X's. My eye kept calling them at 7:00, but it was just seeing wrong that day, and if I had followed the advice from the git-go, I'd only have dropped one point instead of three in that phase.

The nifty thing about that method is it treats a shooter and shooting system as an amplifier with in-phase feedback that has the potential to oscillate if the gain is one or more (Nyquist's criterion). The feedback is the spotter position and the gain is how far the sights are adjusted to attempt the correction. If that adjustment is 100%, the gain is 1.0, and oscillation ("chasing the spotter") can result. By making less than full correction, the oscillation is damped out.

[hounddawg]

I am hoping using his method is going to overcome my biggest obstacle which is centering my groups. Not a whole lot of reloading in his books but he has excellent advice on technique and that is my weak link in the chain

[Unclenick]

When you consider service rifle match targets can theoretically be cleaned by a 2 moa (at 600) gun, you realize the shooter's technique is the weak link in most shooting. Making guns mechanically more accurate is almost a separate hobby, though it does a lot for confidence to have a tight-shooting rifle.

[hounddawg]

When you consider service rifle match targets can theoretically be cleaned by a 2 moa (at 600) gun, you realize the shooter's technique is the weak link in most shooting. Making guns mechanically more accurate is almost a separate hobby, though it does a lot for confidence to have a tight-shooting rifle.

for F class I think you need to have ammo and a rifle that will shoot .5 MOA 5 shot groups at 100 consistently. Once you start stretching it out the shooters ability comes more and more into play as the distance increases. I used Owens method for zeroing this morning, the wind was negligible at 300 at about 2 - 5 mph from right to left. Moderate mirage. 3 groups of 3 sighters then the last 11 into a seperate target

[Unclenick]

Unless you have 1/8" or 1/10" clicks on your sight, that's as close to true zero as you can expect to get. Good shooting!

[Bart B.]

Originally Posted by hounddawg

for F class I think you need to have ammo and a rifle that will shoot .5 MOA 5 shot groups at 100 consistently.

For F class, I think you need to have ammo and a rifle that will shoot sub .5 MOA 5 shot test groups at competition ranges consistently. Doesn't matter what it shoots at 100 yards.

Groups for a given load don't have the same subtended angle at all ranges. Variables causing this include bullet velocity, departure angle and BC along with atmospheric conditions. You may need one charge weight for closer ranges and another for further ranges. Or a tuner set for each range with one load.