I suspect, but do not know, that there are considerable differences in harmonics between tapered and straight barrels, and I suspect that maybe these differences in harmonics might possibly influence the ability to tune a barrel using different loads and bullet seating depths, among other factors. This is there a preference for straight vs tapered BR rifle barrels for long range and also for short range precision shooting.
Do harmonics on tapered vs straight bull-nose barrels influence tune-ability?
- Thread starter Cassidy
- Start date
jonbearman
I live in new york state,how unfortunate !
Keep in mind that at shortrange and long range there are weight limits to stay within the rules.I would think if you could run a straight 1.350 for 200 yds , many might choose it for stiffness but in real world terms there are rules with strict weight limits.
To answer the question, yes, the straight vs. straight barrel does influence harmonics and tunability. Is either an insurmountable goal? No. They can both be tuned.
And as jonbearman said, weight limits have much to say about the taper of the barrel you use. In short range BR, the taper of the barrel even has limits. Now add to all this and the weight limits and you have another problem. That problem is balance. If you stick a heavy barrel on a light stock you get or can get a rifle that is nose heavy and out of balance.
And as jonbearman said, weight limits have much to say about the taper of the barrel you use. In short range BR, the taper of the barrel even has limits. Now add to all this and the weight limits and you have another problem. That problem is balance. If you stick a heavy barrel on a light stock you get or can get a rifle that is nose heavy and out of balance.
GSPV
A failure to plan is a plan for failure.
There is actually no limit on taper, per SE, in short range benchrest. There are outside dimensions that the barrel must not exceed. So, you could easily shoot a straight cylinder barrel. It just can't be larger anywhere than the max diameter of a LV or HV depending on the class. You could even shoot a reverse taper. Just can't exceed the max diameter anywhere along the LV/HV profile.
I think that one of the two major orgs has one class with no profile limit. This in the interest of promoting experimentation.
There is also another benchrest org, UBR, that doesn't stipulate profile.
But, I know what you meant, and mostly people end up with something like the common profile because they work.
I think that one of the two major orgs has one class with no profile limit. This in the interest of promoting experimentation.
There is also another benchrest org, UBR, that doesn't stipulate profile.
But, I know what you meant, and mostly people end up with something like the common profile because they work.
Both can be tuned and a tapered barrel CAN be stiffer than a straight. Length plays a huge role in barrel stiffness, too.
Here's a link discussing barrel stiffnes and a formula for calculating it. Good read!
--Mike Ezell
http://www.riflebarrels.com/articles/barrel_making/rigidity_benchrest_rifles.htm
Here's a link discussing barrel stiffnes and a formula for calculating it. Good read!
--Mike Ezell
http://www.riflebarrels.com/articles/barrel_making/rigidity_benchrest_rifles.htm
There is a limit on barrel taper if you are considering short range Hunter or Varmint Hunter classes in IBS. You might also consider a hunter taper for your next VFS rifle barrel.
There are reasons for going with whatever contour you or your smith chooses, but as Greg said, if the contour is smaller than the MAX as outlined in the rule book, it can be any contour you want...unless you can show me where the rule book says otherwise.Uthink Uknow said:
GPat
Site $$ Sponsor
I'll start by throwing out the limitations of weight classes and diameter for specific competitive disciplines and just deal with a personal experience of my own.
I built a wildcat some years ago specifically for shooting an unrestricted weight class of varmint rifles for a local range match. I specified the barrel to be 1.25" straight no taper. When I took the components and reamer to my gunsmith he looked it over and told me it would be very difficult to tune and would likely never shoot all that well. I had him build the rifle regardless and after about 10 day trips to the range I finally got that rifle to shoot, and boy did it shoot. After that the rifle shot that specific load and that load only. It wasn't a fire breather so the throat barely eroded even after 3000+ rounds and I never deviated from the powder charge even after several more attempts to find a load that worked a little better.
In this single instance (which may or may not prove true in others) the straight taper barrel was harder to tune, but once that tune was found it didn't budge.
I built a wildcat some years ago specifically for shooting an unrestricted weight class of varmint rifles for a local range match. I specified the barrel to be 1.25" straight no taper. When I took the components and reamer to my gunsmith he looked it over and told me it would be very difficult to tune and would likely never shoot all that well. I had him build the rifle regardless and after about 10 day trips to the range I finally got that rifle to shoot, and boy did it shoot. After that the rifle shot that specific load and that load only. It wasn't a fire breather so the throat barely eroded even after 3000+ rounds and I never deviated from the powder charge even after several more attempts to find a load that worked a little better.
In this single instance (which may or may not prove true in others) the straight taper barrel was harder to tune, but once that tune was found it didn't budge.
GSPV
A failure to plan is a plan for failure.
The rule books do not specify a taper. They specify maximum dimensions. Period. If you stick close to those max dimensions, sure, it ends up dictating a taper.
But, there is no rule that says that you have to stick close to them. E.g., in HV, you could use a straight cylinder barrel that matches the rule book dimensions at the muzzle. Legal? Yes. Would it be competitive? I don't know. Kinda doubt it.
But, there is no rule that says that you have to stick close to them. E.g., in HV, you could use a straight cylinder barrel that matches the rule book dimensions at the muzzle. Legal? Yes. Would it be competitive? I don't know. Kinda doubt it.
I guess maximum is the qualifier in your statement and I don't know that I've ever seen anyone go much below the maximum in the dimensions. I've also never seen anyone shooting a six pound Hunter class rifle either. We all tend to stay close to the maximum.
Alex Wheeler
Site $$ Sponsor
I think this is an area that people get a little mixed up on. My opinion is you want a stiffer setup for short range and some flex for long range. You need to be able to tune a barrel, harmonics allow that, if the platform gets too rigid the tune window seems to shrink. I have seen a trend in some f-class guns. The extra long PRT stock with a 30-32" straight barrel. That is a very flexible combo and it works very well at 1k. They seem to have a nice tune window and have been easy to tune. Everybody wants to stiffen things up today, not a good plan IMO.
zfastmalibu said:
As I said, though...bigger diameter alone does not necessarily mean stiffer. The link I posted is a good read, if you care to take the time to read it. Length is a huge factor to barrel stiffness. A straight barrel will lose rigidity faster with length than a tapered barrel. Perhaps I should phrase that differently....A straight barrel will gain flexibility faster with length than a tapered barrel.
Which reading you prefer depends on whether you believe a more or less stiff barrel tunes best. In my personal experience using tuners, they both tune easily....flip a coin. But a majority of rimfire shooters believe a more flexible barrel tunes best with a tuner. I am not convinced and hope to have some vibration analysis results soon, that will hopefully help definitively with this question.--Mike Ezell
I guess we better not even mention fluted barrels at this time.
Probably not, but they don't get stronger by fluting them, UNLESS compared to an unfluted barrel of equal weight, which of course, would have to be smaller in diameter. This is assuming equal length, too.--MikeUthink Uknow said:
Alex Wheeler
Site $$ Sponsor
Mike,
I was not replying to your post specifically, just making a general statement. I agree that straight barrels loose rigidity when they get long. The 30-32" straight barrels being used are relatively flexible and so is the PRT stock. I am in the camp that believes a slightly more flexible setup is preferred for 1000 yd shooting. It gives a wider tune and less dependence on ES.
I was not replying to your post specifically, just making a general statement. I agree that straight barrels loose rigidity when they get long. The 30-32" straight barrels being used are relatively flexible and so is the PRT stock. I am in the camp that believes a slightly more flexible setup is preferred for 1000 yd shooting. It gives a wider tune and less dependence on ES.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.