We are having all sorts of arguments here about what a barrel tuner can do to improve the accuracy of a rifle.

We have a very sophisticated looking one from HOEHN, Model 4000 PLUS, and are thinking of installing it on a Sako P04R rifle and see what the results are.

You might wish to contact Dick Wright, a member here. He was a longtime columnist for Precision Shooting magazine (on benchrest topics). He has plenty of experience in the area of extreme rifle accuracy, and may well be able to assist you.

Good shooting!

John

My understanding is that the tuner works by extending the mass of the barrel, moving the null spot in vibration as close as possible to the muzzle. This is supposed to minimize the movement of the muzzle in response to the vibration set up by firing the rifle.

The more massive the barrel, the less effective the tuner.

I have never tried this, but I have read that you can observe the vibration and find the null spot by sprinkling a fine line of powder (talcum or dust) along the top of your barrel (first removing all oil, etc). In theory, the powder moves and will accumulate at the null point. May take several shots with a heavy .22 rimfire.

quote:

Originally posted by Saeed:
We are having all sorts of arguments here about what a barrel tuner can do to improve the accuracy of a rifle.

We have a very sophisticated looking one from HOEHN, Model 4000 PLUS, and are thinking of installing it on a Sako P04R rifle and see what the results are.

My experience so far is very limited, having bought a Falcon with tuner last year. I shot it for awhile at the setting it came with, then found out that it had been moved from the original owner's setting. Hmmm...I've started with it at its maximum extension and moved it back five clicks for each target I shoot at ARA matches. The last setting was not good, elevation was inconsistent. Tomorrow I'll try four more settings at an ARA match. I figure I'll shoot a lot of relatively poor targets but might understand the thing in the end.

The one we have is made by HOEHN, MODEL 4000 PLUS.

It has about 24 full turns.

I have installed it on a sported barrel Sako P04R rifle.

I have fired 12, 10 shot groups without it to use as a base.

I installed it on the rifle, and started with it fully screwed in.

I am shooting 6, 10 shot groups at each setting - that one full turn.

I am using ELEY TENEX ammo.

Will post my results.

In selecting Tenex, you have done everything reasonably possible to minimize rimfire manufacturing errors. (I suppose that there are unreasonable extremes, but those are just that.)

I suspect that you will be trying to detect very small differences. If you shoot twelve 5-shot groups at each setting, you will have twice the data. If you shoot 30 two-shot groups, you will have five times the data.

There's a bunch of different theories on what tuners do and the best way to adjust them. I feel like I have just scratched the surface. From what I've learned, the overall goal is to reduce the amount of vertical in groups downrange by minimizing the effect of the variance in velocity from round to round.

In my opinion for best results you should be testing the tuner using a lot# of ammo that has been proven to be consistent. Tenex is pretty good but not a guarantee. If the rifle isn't shooting very consistently to start with, tuning won't help anything. It won't make a mediocre rifle much better or turn bad ammo into good ammo, but it may put an extra edge on an already solid rig. Having an indoor range to shoot in like yours will be very helpful since any significant wind can make this fine testing worthless.

What I've done is set the tuner to zero and then adjust with quarter turns, shooting three shot groups with every adjustment. You'll see groups get bigger and smaller as you go. Then I pick out where the groups were smallest and with the least vertical and test those settings again, and then try shooting a few clicks plus or minus what is producing the best results.

The inside of the tuner may get pretty filthy if you shoot a lot, it's surprising how much stuff can accumulate, so I'd clean it out every time you give the bore a deep scrubbing too.

Contact www.RAStuners.com. They probably know more about tuners than anybody. The company is owned by Jim Bennington, a friend of mine, a retired engineer, who is a gun guy. These are very bright people who have been experimenting with tuners for years.

Tuners are very simple devices in spite of the mystery. I start with it backed up all the way and shoot my base groups. That established, I turn the tuner out just a few thousandths,that's all that's necessary, and shoot two shots. With Red Box, if they don't go thru the same hole, move it out a few more and shoot again. Repeat till they go thru the same hole. Then shoot more shots till you're satisfied.

If I'm going to do more experimenting, I measure the O.A.L. of the set tuner with a caliper so I can return to that exact setting easily.

I made my own tuner for my .17 HMR project that is documented endlessly here. See "My new project".

For optimum accuracy with a rimfire, you really do need a tuner. Have fun!

This is a CZ 452 that I stocked. Note the tuner (my design). This gun is one of a matched pair that I spent a year and a half making.

I took this picture while shooting it on my own range. I was sighting it in and setting the tuner before delivering it to the owner.

A close up of my tiners for the two custom CZ's. The tuners are quite small, only 1" major diameter because of the smallish rifles.

Dick,

Thank you for your input.

I have actually built some tuners very similar to yours, but with repeatable indents with markings so one can return to the same position.

Hoehn 4000 Plus


As you can see above, this is a rather sophisticated and very well made unit.

I have shot a few groups by going full turns between each set of groups.

But, it seems that very small changes can make a difference as you have mentioned.

We are going to be away for a while on safari, and I hope to continue ths test when I get back.