Only necessary on factory barrels. And it does the same general thing as firing 100-150 rounds through the barrel, but does it in a lot less shots. Better off getting the barrel hand lapped by someone who knows what they are doing.
If you are talking about the David Tubb's Final Finish and TMS, then yes, depending on your situation.
It works very well on factory barrels and bringing new life to barrels that have some wear.
I've personally used it on an FN A5-M SPR and a .22lr barrel with excellent results.
The FN gained an additional 400 fps velocity and I don't know if it made it shoot any better, but it definitely didn't hurt.
(The rifle started out shooting 1/4 MOA, and still did after using the Tubb product.)
On the .22LR, it was an inexpensive Green Mountain barrel and it shoots groups that are typical of high end Kidd barrels.
One of the Moderators here Rob01 is a very active competitive shooter and wrote this review of David Tubb's Final Finish and TMS. Link to actual PDF
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Tubb Final Finish and TMS Review
Some of you may have already read the Tubb Final Finish review I wrote back in 2001 on other sites but I’m putting an abridged version here as well as adding some information on another product I have been suing recently, Tubb TMS rounds.
First Final Finish, The product was advertised as "a better barrel in a box." It promised to reduce fouling, ease cleaning, give better velocities, and improve accuracy. So I figured I'd give it a try - I've spent $35 on less important things. The rifle I was going to use this product on was a properly broken-in stock Remington 700P in 300WM. Well, it was almost stock. I had the stock bedded due to excessive play and movement. The rifle shot fairly well, about 3/4 MOA with factory match ammo, but was a bear to clean and fouled very badly. After about 20 shots the bore looked like I had copper plated it. So, this being said, I decided to give the folks at www.zediker.com a call to get some Final Finish.
The .30 kit comes in a plastic case divided into 5 compartments housing the 5 different sets of coated 190 grain Sierra Match King bullets. You get 75 bullets (50 for .338 and larger) of 5 different levels of coarseness, which are coated almost like a moly coat. You will only shoot 50 the first time you do this treatment on a factory bore. The others you save for the future when your barrel needs a little touch-up, like when your throat is getting a little long. You load the rounds and shoot 5 strings of 10 rounds from the coarsest to the finest, cleaning between each of the 10 round strings. Some might say this sounds like a barrel break-in thing, and to a point it is, but you can do this on any rifle and believe me the benefits are much greater than just a break-in.
I loaded up the rounds per the instructions, Zediker can give you loads if needed, and I hit the range to complete the treatment. Some might say that the treatment sounds like a fire lapping, and to a point it does, but from what I've heard about fire lapping this product is easier and less aggressive as far as the bore is concerned. Do not look for accuracy while shooting these rounds. They aren't intended to produce great groups, just smooth bores. Personally I just shot at a large steel buffalo my club has at 400 yards. The whole process took about one-and-a-half to two hours and is pretty painless.
About a week later, after loading up some rounds for load testing, I hit the range. I made more of the same loads as I had used before the treatment so I could test the before and after effects. That load was 72.5 grns of RE 22 and 190grn Sierra Match Kings in Federal Match brass with 215M primers. (Disclaimer: Do not start with this load. Get a good reloading manual and start from their beginning load.) Having already done some testing, I had some velocities from the chrono to check the new velocities against. They say that the Final Finish kit will give you greater velocities, less fouling, easier cleaning, and better accuracy. It does! My velocities with the same loads went up more than 60 fps! Before the treatment my average velocity for the above load was 2833 fps with an ES of
50 fps. After the treatment the average velocity was 2899 fps with an ES of 32 fps. My primers were just starting to flatten with this load before the treatment, but after there wasn't a hint of pressure signs. The pressure must have dropped from the bore being smoother (hence, less friction). Also noted was that there was barely any fouling to be had and cleaning took no time at all. Accuracy, on the other hand, was just a little better. My average 5-shot group before the treatment at 100 yards was .75" and 3.5" at 300 yards. After the treatment the groups shrank to .6" at 100 yards and 2” at 300 yards. A fair accuracy jump combined with the other benefits made me very happy. I just started loading for the 300WM so I'm sure by playing with this basic load I can squeeze some more accuracy out of this factory barrel.
If you are interested and want to read some more on this product go to www.zediker.com. This is where I bought mine from but there are other places that sell it. For about $35, delivered, it was well worth it - especially on a factory barrel. If you load your own give it a try. You won't be sorry.
Now to another product I have found works very well, the Tubb TMS rounds. These rounds are designed to be used on both factory and custom hand lapped barrels unlike the Final Finish which is recommended for only factory barrels. The TMS rounds can be used in two ways, as a break in for new custom barrels and as a throat maintenance system as the name implies. For factory barrels the Final Finish would be a better option for break in as you are treating the whole bore and not just the throat area as is needed in a custom hand lapped barrel.
First for use in break in, when getting a new custom hand lapped barrel the bore itself is very smooth but the throat area is sharp from cutting the chamber. This is what the standard break in is supposed to take care of by smoothing the throat so that it doesn’t cut into the jacket which can degrade accuracy. The TMS method is much easier to use than the old shot one, clean, shoot one method of break in which can take hours. The TMS method is to shoot three TMS rounds, clean and then shoot three more. According to the gentleman at Tubb’s company your barrel is now about 95% broken in. I used the TMS method on my GAP .243 and found it worked very well.
TMS rounds are also used for throat maintenance during the life of your barrel. Approximately every 200-300 rounds firing a couple of the TMS rounds down the bore it will keep your throat area smooth and not allow it to get like alligator skin which can happen from the heat and pressure and cut into the bullet’s jacket damaging the bullet and leaving fouling in the throat area. I have been using the TMS on my .243 and also on my 300WM and found it works.
I also want to add that there was no significant lengthening of the throat when using the TMS rounds. Also according to the gentleman at Tubb’s, the grit used on the TMS rounds is finer than the grit used in the lapping compound used to hand lap the bore so there is no damage to the rest of the bore using these rounds.</div></div>
If you do not already know, you will quickly find out that barrel break in and conditioning is a very controversial topic and is the source of many heated debates on this site.