7mm RUM Barrel Break In and Hunting Loads

[erikljoh]

Hi guys, recently picked up a 7mm RUM, and would appreciate any input on barrel break in with a caliber like this.

Also, what bullets would be best to hold up under the velocity? I am currently thinking about the Nosler Accubond or the Scirroco, but around 3200, will they hold up on deer/boo/black bear?

 

[Varmint Hunter]

Break-in would be no different than for any other cartridge. I usually shoot once and clean for the first 5 rounds, then shoot 3 and clean for the next 5 groups. Lastly, I shoot 5 and clean for 5 groups. That should take 45 rounds. It bwill also provide you with a box of once fired brass and an idea of what loads look promising.

Everyone seems to use a different break-in method but they are all variations of the same process.

Either bullet should work fine for your intended game. The Accubond is harder and will provide better penetration while the Scirroco should give better expansion. If short range impacts are expected then I'd opt for the tougher bullet.

The 160gr Accubond shoots very well from my 7STW and would be a good choice in any high capacity 7mm cartridge. The Hornady Interbond is similar to the Nosler Accubond but is said to expand a bit quicker and cost a little less.

VH

 

[Ian M]

Varmint is right about there being lots of different methods employed for breaking-in a barrel. I am switching to one suggested by Garry Schnieder - shoot singles till the barrel seems to be responding and is cleaning up quicker. That might be after a dozen shots or less with some custom barrels and might never happen with a particularly rough factory tubes. In the case of a rough barrel, after 20-25 shots I would simply make the statement - "You are now broken in, you SOB!" and shoot the hell out of it.
Check Dan Lilja's site to see a great video of the inside of a barrel - it came out of a long green box.
There is also an article in this issue of the NRA American Hunter on barrel break-in - for what it is worth.

 

[Varmint Hunter]

Here is Dan Lilja's take on barrel brake-in.

Barrel brake-in

 

[erikljoh]

Appreciate the input. I think the Accubond will be the way to go. I will let you know the results.