Muzzle Weight Specs?

[AlanF]

I'm impressed with the idea of using a muzzle weight to widen the barrel vibration nodes and make load tuning easier. One disadvantage of my barrel clamp setup and 1.25" parallel barrel is that nodes are narrow. I intend to persist with the barrel clamp, but have ordered a 33" Lilja tapering to 1" at the muzzle. Would anyone be prepared to reveal some specs for their weights e.g. material, length, diameter, attachment method, position in relation to muzzle?

[Bindi2]

I'm impressed with the idea of using a muzzle weight to widen the barrel vibration nodes and make load tuning easier. One disadvantage of my barrel clamp setup and 1.25" parallel barrel is that nodes are narrow. I intend to persist with the barrel clamp, but have ordered a 33" Lilja tapering to 1" at the muzzle. Would anyone be prepared to reveal some specs for their weights e.g. material, length, diameter, attachment method, position in relation to muzzle?

Why we need all the help we can get .

[Brad Y]

Alan, most seem to be in the order of 500-700gr. I think Dave Mc did one about 900gr from discussion on another post somewhere. I dont think length matters too much but wouldnt go longer than 5 inches. My next one will be 4 inches and made from 38mm bar stock, taper bored to fit the barrel and loctited on. This barrel looks like a keeper so if the weight has a negative effect, I can take it straight off. The last one was 50mm bar stock and a couple of inches long and threaded on- wont be doing that again. Depends if you want the coke can short and fat look or something a little less out there in diameter but a bit longer to keep the weight up.

[Bindi2]

It needs to be adjustable. The weight and shape are yours to decide.

[Cameron Mc]

Alan, I made 8 weights before the world champs last year.
I did not use any science for the dimensions. All mine are threaded to a sleeve that I loctited to the barrels.
Mine are all 1.5" diameter x approx. 5" long. I used 316 stainless. The weights are flush with the muzzle.

The next one I make will be bored to slip straight onto the barrel and fixed. Like Brad suggested.
I have found the primary benefit of the weight is the mass not the adjustability.
Just for interest, Marty's are glued straight to the barrel, and we know how he went at Raton

Hope that helps
Cam

[AlanF]

Thanks Brad and Cam.

Cam I calculate yours would be adding about 630 grams to a 1 inch diameter barrel. I think Marty once said his was around 7 or 800, but don't quote me on that. BTW DaveMc was very impressed with your vertical in the teams event at Raton Cam, so your weight must be pretty close.

Is taper boring a straight-forward process? I won't be doing it, but is it something that can reasonably be done on a gunsmith's lathe?

Alan

[Cameron Mc]

G day Alan

Those weights you quoted are very close.
Taper boring for a gunsmith should be no worries. It is done on a "gunsmith type, centre" lathe.

Cam

[Brad Y]

Bruce I will disagree with you on it being adjustable. If you want a tuner then yes you want it adjustable. If you want a dampener weight only then no. I wont be putting a tuner on any barrel anymore apart from a 22lr.

Alan- yes taper boring can be done but need to be wary of chatter over long distances. Slowing the speed and reducing the depth of each cut would help (im no machinist but this is what Im told). Might be able to get a couple of pics of mine over the weekend if Im lucky.

[Brad Y]

Funny story Alan, your above posts regarding estimated weight for Cams weights made me re check my calculations for mine... yes again its been proven I should have paid more attention in maths class Off to the metal place tomorrow to get some more bar....

[williada]

Hi Alan,

It’s nearly time for me to do a run outside as the moisture is lifting off the grass. So this will be briefer and perhaps I can add more at lunchtime for what it’s worth. I have mentioned before the role a fundamental weight plays in lengthening that node. But the overall weight of the tuner can still have a variable part in it, so the fundamental weight is still a fundamental weight. You can have the best of both worlds i.e. one to increase the length of the node and the other to follow a micro tune all built into the same fundamental weight.

I agree with Cam and have mine threaded on, and Cam’s results have proven the concept. There are many methods to derive the weight and how far it should extend past your muzzle. But beware that weight might be heavier than you think. If it is, then you can still get the benefits of a lighter variable tuner for following a node and playing with group shape. The latter is important for compensation. Or you can have a lighter fixed weight and hope it’s about a node counter. The other things that matters are (a) the bore size of the tuner for the conditioning of the internal atmosphere; and (b) that there is not a Mr average weight for all barrels. The weight is dependent on a major vibration near your muzzle.

It may be found in two ways. Firstly, I make a slave tube of correct internal size and thread it on. It also has an external thread by which I add weights. These weights can be screwed hard up against each other for test purposes. I simply add weight to the tube until two different loads I prepare to induce the vertical group form in the same spot at a set distance. You can then make a new tuner based on that weight as one piece or you can make a variable one of the same weight. I prefer the variable, because then I go about manipulating that to duplicate my best nodal tune from load development without the tuner on. That then becomes the base line for future adjustments particularly for altering group shape and taking out lateral.

The other way is the witch doctor method of ringing a barrel, to find that last node near the muzzle by holding the bare barrel between your fingers and tapping it so it keeps ringing. You must base calculations on finding the middle of the harmonic node to the end of the muzzle for the counter weight. The weight then depends on the weight of the metal in this distance and seeing that in oz per inch and then multiplying that by a factor of 1.5 then placing the weight forward of the muzzle by the distance from the centre of the node to the muzzle multiplied by 1.5. It becomes a heavy long bit of gear.

If you are using a variable tuner, you have to know where your micro peaks and troughs are, so sometimes you wind it one way to find a peak and the other to find a trough. These are small amounts. Or you can go big from say peak to peak skipping the trough. David.

[Bindi2]

Alan, I made 8 weights before the world champs last year.
I did not use any science for the dimensions. All mine are threaded to a sleeve that I loctited to the barrels.
Mine are all 1.5" diameter x approx. 5" long. I used 316 stainless. The weights are flush with the muzzle.

The next one I make will be bored to slip straight onto the barrel and fixed. Like Brad suggested.
I have found the primary benefit of the weight is the mass not the adjustability.
Just for interest, Marty's are glued straight to the barrel, and we know how he went at Raton

Hope that helps
Cam

Interesting we have found the position is barrel specific using both threaded sleeves or grub screwed direct to barrel. Size seems to be immaterial, not having tried two different weights on one barrel for comparison.

Williada has nailed in much better prose then I.

[AlanF]

David,

The only tuner success I've had was with a heavy tuner which improved a barrel dramatically just by screwing it on. Adjusting its position didn't seem to improve things any further, or at least not reliably. I remember with another tuner getting a fantastic group at the home range then taking it to NSW Queens where it was very ordinary. I prefer the concept of widening the nodes, then load tuning. It seems to be more tolerant of different conditions. I accept that tuners have the potential to take things to the next level, but there's a lot of good shooters who haven't been able to master them. In benchrest smallbore, some of the best exponents are literally firing thousands of rounds testing in different conditions to get sufficient data for tuner settings. I say good good luck to them.

Alan

[Bindi2]

Maybe there is a point in weight when a tuner becomes just a barrel weight. That begs the Q do you dead weight the barrel or tune with a lighter adjustable weight or find the correct weight for your barrel.

[Brad Y]

Totally agree with Alans comment. We have to remember that we are shooting F class for score over a whole day/weekend or week of shooting competition. One tight group on one particular occasion doesnt do any favours. I had no repeatable success with a tuner, one detail it would look good, go back 100m and it was a flop. Constantly worrying about re adjusting to get it right, when the focus needs to be soley on wind reading. But having the weight on the barrel showed marked improvement just by being there without any particular setting. Some barrels wont need a weight at all- aka 'the hummer'- and both the long range benchrest guys and F classers are always on the lookout for one of these.

Of course you could do the specific testing to see what weight works best. Remembering there are still limits for overall rifle weight. Anything around the 600-800gr mark seems to be working so dont see the need to change that at the moment. Lighter barrels such as palma and LV could get away with lighter weights, stiffer barrels might need more weight to make an impact on such a stiff barrel. One thing is still for certain- no barrel weight can entirely make up for poor load development.

[Bindi2]

It appears to me that there is two lines of thought giving two means to do the same thing. Is one better than the other I doubt it. Is one easier to do yes but will it have other effects over time maybe.
Yes Brad we shoot for score. If your rifle holds a smaller group across all ranges than the next guys you have a better chance with the wind. The wind shots will show as lateral water line depending on direction giving the measurement you should have made if any by which you learn. One thing I have learnt is that the flags in use are not very good indicators for F/C to hold X ring. The reason being they are to course for 1MOA and or to slow.