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Adjusting barrel length to tune load???

When you have a rifle built you no doubt head to the range with 5 or 6 loads near the top of your calibers capability and hope for one of the faster loads to group well. When it doesn't and you want to experiment is it possible to shorten barrel length to adjust the harmonics for a faster speed node. I realize it's a drastic measure and shorter barrel means less speed but could you end up with a faster accuracy node?
 
If you look at the size of tuner adjustments, I think that it would be possible that the length adjustments that would be needed for this approach would be much smaller than you might imagine. As an alternate, there are a couple of tuner brakes on the market, and if they were too large in diameter you could build a muzzle brake so that weights could be attached for tuning.
 
Boyd is correct, I've had a couple R.A.S tuners installed on my rifles, adjustments were very small that corrected vertical on target.
 
As an example, let's look at the straight 284 for F-open.

With H4350, my 32" barrels will tune at 2800-2810. Pressures are mild, but the next node up is too hot.

With H4350, a 30" barrel will tune a little faster 2825-2850 (per my friends - not my personal experience). The next node is well out of reach.

Now, if I change powders, the 32" can go faster and have good accuracy in a higher node. That has to be tempered with the knowledge that the most successful F-open competitors seem to gravitate to H4350. Between them and myself, it seems that there is a sweet spot that defies explanation.

On the other hand, I'm married to H4350 for a while and am considering running a little shorter, stiffer barrel for F-open next year.
 
I'm a firm believer that a very good shooting rifle is a result of the entire package working in "harmony". To support this, I took a very average barrel that two previous owners said was not competitive, set it back, cutting the entire tenon off and rechambered..literally in a 3 jaw with no indicating of the chamber and screwed it onto a Teddy action in an old style McMillan br stock and shot it. The gun absolutely shot lights out! In fact, the person I got it from and a friend of his stopped by the shop shortly after me putting the barrel on. I had them both shoot the gun. They both shot groups in the zero's and ones right away and were raving about how it shot. The friend that sold me the barrel asked what I had done to my rifle..that it was shooting as well or better than any gun he'd ever had his hands on. I told him that I had just put his old barrel on my rifle and that he just shot it. He couldn't believe it!

As I said, I didn't even indicate the barrel when I rechambered! I did nothing to "correct" anything. That loser barrel was simply shortened by a little over an inch and screwed onto a different action in a different stock. I won a lot of wood with that barrel and it remains one of the best shooting barrels I've ever had, to this day. Go figure that one out. It had to be related to everything working together as a package that made it shoot the way it did. The two previous owners both said the barrel was a tomato stake and I bought it for very little or nothing.

If you know me, you know that I'm a very, very strong advocate for tuners. I've experienced things like I just described with tuners making guns come alive...although, I don't claim this as a result that should be counted on. The expected benefit of a tuner should be a wider tune window and adjustability. That said, seeing things like this as a result of trying to make it happen this way, I'm sold that the entire rifle, along with the respective barrel length, play a big part in how the rifle is judged. I often wonder how many "hummers" are passed of as average that may have just been cut at the wrong place.

Food for thought.
 
When you have a rifle built you no doubt head to the range with 5 or 6 loads near the top of your calibers capability and hope for one of the faster loads to group well. When it doesn't and you want to experiment is it possible to shorten barrel length to adjust the harmonics for a faster speed node. I realize it's a drastic measure and shorter barrel means less speed but could you end up with a faster accuracy node?

If you want to go this route just cut a deep crown and take a file to the front of the barrel to tune it. Should work in theory. Just don't go too far :eek:
 
I'm a firm believer that a very good shooting rifle is a result of the entire package working in "harmony". To support this, I took a very average barrel that two previous owners said was not competitive, set it back, cutting the entire tenon off and rechambered..literally in a 3 jaw with no indicating of the chamber and screwed it onto a Teddy action in an old style McMillan br stock and shot it. The gun absolutely shot lights out! In fact, the person I got it from and a friend of his stopped by the shop shortly after me putting the barrel on. I had them both shoot the gun. They both shot groups in the zero's and ones right away and were raving about how it shot. The friend that sold me the barrel asked what I had done to my rifle..that it was shooting as well or better than any gun he'd ever had his hands on. I told him that I had just put his old barrel on my rifle and that he just shot it. He couldn't believe it!

As I said, I didn't even indicate the barrel when I rechambered! I did nothing to "correct" anything. That loser barrel was simply shortened by a little over an inch and screwed onto a different action in a different stock. I won a lot of wood with that barrel and it remains one of the best shooting barrels I've ever had, to this day. Go figure that one out. It had to be related to everything working together as a package that made it shoot the way it did. The two previous owners both said the barrel was a tomato stake and I bought it for very little or nothing.

If you know me, you know that I'm a very, very strong advocate for tuners. I've experienced things like I just described with tuners making guns come alive...although, I don't claim this as a result that should be counted on. The expected benefit of a tuner should be a wider tune window and adjustability. That said, seeing things like this as a result of trying to make it happen this way, I'm sold that the entire rifle, along with the respective barrel length, play a big part in how the rifle is judged. I often wonder how many "hummers" are passed of as average that may have just been cut at the wrong place.

Food for thought.


As i read this i'm chuckling, it's making me think about something that happened a few years ago. A friend of mine that is a very good FTR shooter got a barrel that was supposedly a tomato stake and not worth a nickel from another very good well known FTR shooter. He took the barrel and set it back and put it on his rifle, the gun was a laser. He then shot the gun in a long range state championship and won it beating the other guy that he got the barrel from in the first place.......I still laugh thinking about it.......lol
 
I have a good friend that has won more F-class & LR BR than i can count on all the fingers and toes a few times over. He shoots a modified 6.5-06 Baer and always adjusts his barrel length to his pet load that sits 141's at 3150. If you are set up to do your own machining I am convinced that is a sound option.
 
If you want to go this route just cut a deep crown and take a file to the front of the barrel to tune it. Should work in theory. Just don't go too far :eek:
In rimfire, I think they call that, Sporter Class.:) True story.
They aren't allowed tuners, so they have devised barrel contours that place weight at the muzzle and backbore/machine to tune. Of course, they don't have the luxury of loading their own ammo. Instead, they test and test different lots until they find a good lot of Tenex or similar, that works with their set tune...then test some more, for another lot number for when the first lot goes out of tune...many carrying two or more lots of tested ammo to the bench.

The only difference I can see in this and adding or reducing powder charge in centerfire..is that adding or reducing powder charge is easier and more predictable.

Both methods can and do work. In the case of sporter class in rf, they have the benefit of a mass at the end of the barrel similar to a tuner..it just doesn't move but does give the benefit of a wider tune window..as does any mass at the end of the barrel. The problem comes when..not if, the tune for the day changes. Having an adjustable tuner gives one the ability to keep a single load, or a single lot of ammo in tune with just a small nudge of that dog knot on the end of your gun. HUGE!!!
 
In rimfire, I think they call that, Sporter Class.:) True story.
They aren't allowed tuners, so they have devised barrel contours that place weight at the muzzle and backbore/machine to tune. Of course, they don't have the luxury of loading their own ammo. Instead, they test and test different lots until they find a good lot of Tenex or similar, that works with their set tune...then test some more, for another lot number for when the first lot goes out of tune...many carrying two or more lots of tested ammo to the bench.

The only difference I can see in this and adding or reducing powder charge in centerfire..is that adding or reducing powder charge is easier and more predictable.

Both methods can and do work. In the case of sporter class in rf, they have the benefit of a mass at the end of the barrel similar to a tuner..it just doesn't move but does give the benefit of a wider tune window..as does any mass at the end of the barrel. The problem comes when..not if, the tune for the day changes. Having an adjustable tuner gives one the ability to keep a single load, or a single lot of ammo in tune with just a small nudge of that dog knot on the end of your gun. HUGE!!!
Rim fire shooters believe that the barrel must be choked to shoot. and if you thread the barrel for a tuner it won't shoot .
We thread one that didn't shoot and put our tuner on it. The x count and score went up over 40 percent . Larry
 

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