Testing smallbore ammo lots: tuner tube on or off?

[TRSR8]

Mike Bush is a friend, he has a distain for some in the RFBR crowd, not the entire crowd, academic since he,’s no longer with the company.
I shot 2 Swindlehursts and shot CFBR with the guy that developed about 1/2 of it with Vick.
Ron Hoehn? Shot RF & CF with him, bought a lot of gold box from him.
My opinion matches exactly Gordons, through wins, not experimentation, like I said, easy to find.

 

[TRSR8]

So back to topic, I just spent a couple weekends testing a few lots of ammo I have and also working out tuner settings. The following is my experience so far:
- Great lots of ammo shoot good to great regardless of whether the tuner is attached or tuned perfectly.
- I cannot agree yet that one tuner setting is the right answer for all ammo. That said, the tuner setting I'm having good success with puts me in a good place for most all of the ammo and it's just a matter of fine tuning.
- Statistical significance is a rathole you'll never escape from. Regardless of whether you're tuning or testing in 5-, 10-, or 20- shot groups, the ammo is not as good as its best group nor is it as bad as its worst group. So if you find an ammo or setting in your testing that's promising, take the best few options and test them again. And again. In many cases, the one with the best initial group can show a flier or two but one of the other good ones will prove reliable over and over again.
- Tuning / testing in not-calm conditions is more difficult however it can be very useful. While tunnel / calm testing is great for many reasons, I'm not convinced that it provides the best information about what shoots best in wind. I think some ammo lots simply buck the wind better and dope more reliably.

Other than preliminary testing, shooting groups is a waste.
One way to verify good/great ammo….shooting targets. Plenty of examples of ammo that groups well not worth a damn on actual targets. Guys with major track records virtually never waiver on this simple fact.

 

[dgeesaman]

Other than preliminary testing, shooting groups is a waste.
One way to verify good/great ammo….shooting targets. Plenty of examples of ammo that groups well not worth a damn on actual targets. Guys with major track records virtually never waiver on this simple fact.

So you won't use a test tunnel? Or do you count lot selection as preliminary testing?

 

[TRSR8]

So you won't use a test tunnel? Or do you count lot selection as preliminary testing?

Yes I have, both ELEY and Lapua, for Lapua it is now, unfortunately, about the single way to get a case, but it has it’s flaws and more than a few top flight shooters will not, have not been to big matches because of top grade ammo sourcing difficulties. The world we live in at present, you pays your money and takes your chances.

 

[USMCDOC]

particle tuners work well but the upptergraft tuner tubes don’t work well on br rifles in rests although they seem to work for those who hold onto their Annie’s in prone

this last target was my last target at Perry,

 

[USMCDOC]

Other than preliminary testing, shooting groups is a waste.
One way to verify good/great ammo….shooting targets. Plenty of examples of ammo that groups well not worth a damn on actual targets. Guys with major track records virtually never waiver on this simple fact.

Tim,

That post above, i only have shot that rifle in one benchrest match.. i was indoors at Kettlefoot on a two pc rest setup. IR50/50 10 shot target.. 250-13X i thought that was pretty darn good for that rifle..

 

[JimSC]

A tuners overall effect depends on the stiffness of the barrel. If you have a long thin taper you are going to see more barrel whip than a shorter stubby barrel. Since you say you change settings according to your ammo Sounds like you have a taper barrel with a good amount of flex. I would use my chrono and see if I could match the FPS to a known ammo's setting.

 

[kevin nevius]

my327vette (great name BTW - do you own one?):

Just my opinion here - tuners (traditionally) are a mechanism of fine tuning. When I initially set up a barrel, the placement of the crown is the critical issue. You need great baseline accuracy to start with, or a tuner will never get you there.

But the system needs to be tested exactly as it would be in competition (whatever your discipline is). Testing without a tuner is just too large a variable to hope to learn anything reliably about how the system will perform with it (if tested without).

When I finish a barrel, I test it just as it would be used in competition - with the tuner in a midrange setting. I look for good baseline accuracy - and round groups (preferable without vertical / horizontal dispersion or "stringing"). If I don't see it, I set back the crown incrementally and retest. Something in the .450" outside edge with roundness is probably workable (if I had to put a number on it). Then start your tuner testing.

Again, just my (very humble) opinion. Wishing you the best,

kev

 

[VLNBYR]

A word about the ammo test tunnels......They are not there to help you get your rifle tuned, that is your responsibility. Their sole purpose is to give you a choice of different lots, all shot under similar conditions. They can only offer you the best of what they have there at that time, not what may be the BEST lot for your rifle. Their ammo lots are not pre-selected in any way so don't expect their lots to be the magic bullets that will make your average rifle into a match winner.

 

[TRSR8]

Tim,

That post above, i only have shot that rifle in one benchrest match.. i was indoors at Kettlefoot on a two pc rest setup. IR50/50 10 shot target.. 250-13X i thought that was pretty darn good for that rifle..

Absolutely, a fine target for initial match, especially indoors which can have peculiar conditions often.
Also, pretty nice targets above, congrats.

 

[TRSR8]

A tuners overall effect depends on the stiffness of the barrel. If you have a long thin taper you are going to see more barrel whip than a shorter stubby barrel. Since you say you change settings according to your ammo Sounds like you have a taper barrel with a good amount of flex. I would use my chrono and see if I could match the FPS to a known ammo's setting.

That, friend, is incorrect, especially the FPS match. Good ammo is good ammo mine, anywhere from 1040 to 1080. Put the chromo in the closet.

 

[TRSR8]

my327vette (great name BTW - do you own one?):

Just my opinion here - tuners (traditionally) are a mechanism of fine tuning. When I initially set up a barrel, the placement of the crown is the critical issue. You need great baseline accuracy to start with, or a tuner will never get you there.

But the system needs to be tested exactly as it would be in competition (whatever your discipline is). Testing without a tuner is just too large a variable to hope to learn anything reliably about how the system will perform with it (if tested without).

When I finish a barrel, I test it just as it would be used in competition - with the tuner in a midrange setting. I look for good baseline accuracy - and round groups (preferable without vertical / horizontal dispersion or "stringing"). If I don't see it, I set back the crown incrementally and retest. Something in the .450" outside edge with roundness is probably workable (if I had to put a number on it). Then start your tuner testing.

Again, just my (very humble) opinion. Wishing you the best,

kev

Yet another national champion , but humble, and sneaky corvette guy giving a consistent message.
Folks.....these are the guys you listen to IMHO.

P.S. I owned three 327 Vette's , 2 327/350 & 1 327/375 fuelie. Best engine Chevy ever made.

 

[USMCDOC]

Absolutely, a fine target for initial match, especially indoors which can have peculiar conditions often.
Also, pretty nice targets above, congrats.

thank you sir

 

[JimSC]

That, friend, is incorrect, especially the FPS match. Good ammo is good ammo mine, anywhere from 1040 to 1080. Put the chromo in the closet.

then God help me if I brought rifling twist, barrel taper in regard to stiffness, bullet bearing surface, bullet weight, and acceleration into the mix

Do you understand barrel harmonic theory or optimum barrel timing ?
Maybe you want to explain what you think a tuner does and how it affects the harmonics. Maybe tell us what affects barrel flex and why every barrel is different

My old Remington 40X with a reverse taper 27 inch barrel is extremely sensitive to tuning. I put the same tuner on a 16 inch Varmint barrel and I can move it from one end to the other and see almost no change in groups size or shape

This is going to sound like sacrilege also but with the trend today of thicker heavier barrels I am beginning to wonder if they are necessary with the proper ammo and if a heavier tuner is necessary. I am ordering a new barrel this afternoon and will be ordering it unthreaded. If after playing with it a bit I may or may not install a tuner

Edit - as long as I am on the soap box in rimfire about the only thing you have to worry about is FPS and even that is pretty standard. The bullets are roughly the same weight and shape, the powder has the same burn rate etc. any adjustments needed are minor unless you are going from the sub sonic to high velocity or sub freezing to 100F. Try centerfire where something as minor as going from CCI to Remington to Federal primers can throw the tune out due to the primer's brisance or going from a Berger to a Lapua bullet of the same weight because of the difference in bearing surface

 

[Shiner Taste Tester]

This is just my .02 cents. I start testing WITHOUT the tuner first., because I like to shoot the scoped half of the match without the bloop tube / tuner on my rifle acting like a wind sail. My thinking is if a rifle will shoot well without a tuner it will really shoot with a tuner on it.

Howard

 

[USMCDOC]

My old Remington 40X with a reverse taper 27 inch barrel is extremely sensitive to tuning. I put the same tuner on a 16 inch Varmint barrel and I can move it from one end to the other and see almost no change in groups size or shape

That's because that 16 inch barrel needs more weight that the reverse taper 27 inch barrel.. and that is why you can move that tuner from the reverse taper barrel on your 16 inch barrel from one end to the other with not noticeable difference because that tuner for the 16 barrel isn't heavy enough..

 

[JimSC]

That's because that 16 inch barrel needs more weight that the reverse taper 27 inch barrel.. and that is why you can move that tuner from the reverse taper barrel on your 16 inch barrel from one end to the other with not noticeable difference because that tuner for the 16 barrel isn't heavy enough..

yep exactly right, all this tuner stuff is really pretty simple when you think about it

 

[TRSR8]

then God help me if I brought rifling twist, barrel taper in regard to stiffness, bullet bearing surface, bullet weight, and acceleration into the mix

Do you understand barrel harmonic theory or optimum barrel timing ?
Maybe you want to explain what you think a tuner does and how it affects the harmonics. Maybe tell us what affects barrel flex and why every barrel is different

My old Remington 40X with a reverse taper 27 inch barrel is extremely sensitive to tuning. I put the same tuner on a 16 inch Varmint barrel and I can move it from one end to the other and see almost no change in groups size or shape

This is going to sound like sacrilege also but with the trend today of thicker heavier barrels I am beginning to wonder if they are necessary with the proper ammo and if a heavier tuner is necessary. I am ordering a new barrel this afternoon and will be ordering it unthreaded. If after playing with it a bit I may or may not install a tuner

Edit - as long as I am on the soap box in rimfire about the only thing you have to worry about is FPS and even that is pretty standard. The bullets are roughly the same weight and shape, the powder has the same burn rate etc. any adjustments needed are minor unless you are going from the sub sonic to high velocity or sub freezing to 100F. Try centerfire where something as minor as going from CCI to Remington to Federal primers can throw the tune out due to the primer's brisance or going from a Berger to a Lapua bullet of the same weight because of the difference in bearing surface

You can lead a horse to water but a few of’em still die of thirst.
Centerfire??? Well, I’ve won IBS aggs, IBS 2 gun, Placed 2nd 200-300 IBS nationals, submitted HV world record group…….does that count?

P.S. trend toward thicker barrels? Today they tend to be around .900”. Twenty years ago they tended to be around .900”

 

[JimSC]

Centerfire??? Well, I’ve won IBS aggs, IBS 2 gun, Placed 2nd 200-300 IBS nationals, submitted HV world record group…….does that count?

did you adjust your powder charge for afternoon vs morning relays? 30F days vs 90 F days ? if so why ?

 

[TRSR8]

did you adjust your powder charge for afternoon vs morning relays? 30F days vs 90 F days ? if so why ?

I could go into detail but I’d have to charge you for lessons.
You continue to associate CF and RF……. Wrong then…..wrong now.
Lots of opinion for a guy with little experience.