FIRECRACKING

[tdboomer]

What is this..how does is happen..tried to google but got no real information.

 

[Preacher]

It's when your throat and and a ways into the rifling look like a dried up lake bed, all cracked and groovy looking from to much, to fast..........

 

[eggman]

Look at about any 22 Dasher with a borescope after it has been shot a fair amount and chances are you will be able to see firecracking.

Rodney

 

[Preacher]

I see it in 22/250's quite often......
I saw it in my 22/6mm AI a lot

 

[Dans40X]

Take a peek in a 50BMG chambered barrel with a bore scope if you want to witness fire cracking-
Flitz is the only compound that I've used,spairingly)to remove carbon from fire cracked 50Bbls.

225-250gr of powder torching off 50 BMG rounds raises havoc in bores.

 

[GerryM]

Preacher has it right > It looks like a dried up lake .
This happens . It's also called errosion. The first stage is the slight cracking then it starts to wear away the lands making them uneven . then it extends farther and farther as you continue shooting more and more rounds. Fact is some fire crack sooner then others. It all depends on the particular lot of steel. You can get pretty good accuracy for at least 2000
round on a normal case like a 222 or 223 or 308.
Mags make them go faster and so does that 22/250 with slow powders. Hot loads are sometime the culprit along with very slow powders. Keep your velocity at a reasonable rate and your wear should be normal.
I hope this helps explain what's going on .

 

[fdshuster]

Have watched it happen to Shilen, Hart, krieger, etc. w/ my 'hawkeye'. Sometimes makes you want to cry when one of these extreme high quality barrels is gradually destroyed. When the firecracking becomes severe enough, little chunks of steel begin to depart from the surface of the lands,edges first) and the grooves, usually where they meet the lands, in the 90 degree corner. Put on a new barrel though, and it's like getting a new rifle.

 

[OldDoug]

Remember there is a difference between fire cracking and the normal look of a stock commercial rifle barrel where the cutter or button pulls the metal. That is ugly also.

Hawkeye borescopes can be scarey!!

Alligator skin heat cracking is part of the varmint hunting game.

If you overheat the barrel, fire/heat cracking will result.

 

[fdshuster]

OldDoug: In my experience, firecracking will result, as a by-product of the intense heat of the burning powder. Yes, I agree, a steady diet of rapid fire, as in CMP & NRA Hi-power matches, with an AR-15 in 223, will burn-out a barrel faster when compared to a bolt-action, fired single-shot, also 223. Rapid fire will accelerate the firecracking, just as a large over-bore cartridge,243 for example) will give shorter barrel life, compared to a 6BR. Just my opinion: whatever the cause, it gets ugly. I try to think of the barrel as another expendable item, no different than bullets, primers, etc. that needs to be replaced, and that cost must be factored in to the cost of each shot fired.

 

[bingo1010]

Attaching a picture,and details) of fire-cracking from one of my barrels.

Happy Shooting
Donovan Moran

just out of curiosity, how did the 243 shoot with the barrel looking like that??

 

[lloydx2]

The average 30 cal barrel lasts about 3 seconds

 

[Ackman]

As it was explained to me by a barrelmaker. The extreme pressure and heat of firing cause the throat to expand very quickly, then it contracts. Heat and expansion/contraction will over time cause work hardening to where those little breaks in the metal surface start to appear.......firecracking. If heat is allowed to build up without a cooldown, cracking happens sooner.