WOW!
I consulted with the Guru of Barrels and He imparted to me the knowledge of the ages regarding ultimate break-in!
See below how they do it!

...it all started on the kitchen table in a little villa just on the outskirts of Rome...

Uncle Vinny and Little Tony were looking to wring out the last bit of accuracy from the new rifle they'd acquired.

First, they plugged the muzzle with a cork and poured in the latest SuperDuperPooperLuber for the Ferrari engine.  This stuff was slicker than olive oil.  Plugging the breech end with the bolt pulled out, they shook it for 5 minutes and took it outside to hang upside down overnight...

In the morning, they took down the rifle and unplugged it, letting the liquid lightning flow out.  They then took a stainless steel brush on a cleaning rod and pushed it in hard and fast from the muzzle end...stroking it slow and hard on the way in, and pulling it out fast.
This they did precisely 69 times.

At this point, a generous amount of flushing was done by squirting Mama Mia's Vestal Virgin Secret Sauce down the barrel until all the other fluids were out.

Almost finished, Vinny and Tony attached a teeny-tiny-itsy-bitsy tamponlike patch to the cleaning rod and pushed it slowly, ever so slowly up the spout of the barrel, one at a time.
This they did precisely 69 times.
Until the patches came out clean as a, as a, well, you know, CLEAN!

Off to the range they went to test the accuracy of this specially treated barrel.
Before placing a round in the chamber, they muttered some old, very old, secret family incantation and danced a little dance around the bench on which the rifle rested.
Upon completion of the chant and dance, they waved their arms and hands in counter-clockwise cirles over the barrel they had so lovingly treated.
Commencing to load and fire, clean; load and fire, clean; first one round, then 3, then 5, then 20, and finally, after being at the range for over 72 hours of meticulously practicing this ritual of barrel break-in, they were rewarded with groups that were the ultimate in "Tightness".

On the 3rd day, their neighbor in the villa next door showed up with his rifle and they told him the story of their adventure in accuracy.
He nodded his head and proceeded to shoot a group of (pick one: 3,5 or 10) shots that was every bit the equal of Vinny and Tony's beloved jewel of a rifle.

Needless to say, Vinny and Tony were astonished at this feat of amazing shooting accuracy from their neighbor and asked him what it was he did to achieve it.

Brutus, the neighbor, and conqueror of tightness, smiled and said,
"Itsa branda new rifle, I justa shoota the godda-dam thing!!!"

...this spoof brought to you by the fertile , imaginative and demented mind of "BusMaster007"

Posted too early in the morning?

SEEK HELP!!

That's how I break-in all of my rifles.

No offense, but Vinny and Tony are charlatans. If breaking in a barrel doesn't involve dead chickens, rotten fruit, and voodoo, it's all snake oil and a waste of time IMO. Some people use goats to break in their barrels but I don't see the point.

Quoted: SEEK HELP!!

At least I didn't do the "There once was a young girl named Alice" limerick!

The correct way to break in a rifle:
1. Buy rifle.
2. Clean packing grease out of rifle.
3. Lube rifle.
4. Load and shoot rifle as much as you want.
5. clean before putting in the safe.

Break in complete.

oh no the secrets out now, I was hoping to patent it first.