[Reb]

Does anyone know if the Micro-groove rifling tends to lose accuracy from wear faster than a non-Micro-groove barrel? Is it more sensitive to fouling or pitting? With the shallower rifling I was wondering if barrel life was reduced. Any ideas on how many rounds could be fired before wear is noticed?

Odd questions perhaps, but I am having my first experience with the Micro-groove in a 35 Rem. 336

Reb

 

[Jack Monteith]

Hi, Reb:
I've no hard numbers on the .35 Remington, but centre-fire barrels don't generally wear out, they burn out. So high velocity small bores like the .220 Swift and the .243 Winchester don't last as long as the medium bore & medium velocity rounds like the .308 Winchester and the .30-06. The match rifle crowd gave up on the .243 when they found a barrel couldn't make the 1000 round mark.

Generally the rifling at the muzzle still looks like new when the throats done. Sierra expects their test .308 barrels to last over 3000 rounds and they don't baby them. Time is money, so they fire 10 shot groups as fast as they can. Now a .35 Remington operates at 35,000 psi compared to 60,000 psi for a .308 and that means a much lower flame temperature. Combine that with the larger bore and I'd estimate a .35 would last 5000 rounds.

Actually the grooves aren't that shallow. Mine's .352" on the lands and .359" in the grooves. According to Hatcher's Notebook, .359" is the correct groove diameter and Remington Core-Lokts are maybe half a thou fatter than Hornadys, Speers and Sierras.

Bye
Jack

 

[kciH]

These barrels can be more sensitive to fouling if you are using lead bullets. I would avoid lead bullets in a micro-groove barrel, they don't seem to work very well in the limited experience that I have had using them in a 9mm Camp Carbine. The jacket fouling from a 35 Remington is almost non-existant because the velocity is so low. I would think you could probably shoot a box of shells a week for about 10 years, if properly cleaned, before you lost any noticable accuracy with one of these rifles. It may last a lot longer than that if you don't heat the barrel up regularly. Getting the barrel too hot is when I believe the most damage is done becasue the metal is hotter and more susceptible to throat erosion, which is the part of the barrel that "wears out"

 

[Jack Monteith]

Hi, Gents:
Micro-Grooves are a bit trickier than conventional barrels, but not impossible. Here's Marshall's advice.
http://beartoothbullets.com/faq/index.htm
The Micro-Groove section is a fair ways down the page.

Bye
Jack

 

[Reb]

Thanks Jack!

And thanks for the heads up on the 200 gr. Hornady being a bit too tough for the 35 Remington. I put a bag of them back at a recent gun show.

I guess I can't blame the barrel on the 35 Rem. for any serious problems.


Reb