I told my buddy to get a box of UMC ammo to break in the new SS Montana barrels because it was "cost effective".

Thinking about it I wonder if it's a good idea as I'm not sure what type of metal the case is made of.

We're going the "clean after each shot for the first 10 shots then after every 5 shots for the next 30" as recommended by Montana.

We have the Wipe Out & Acceleratore, Bore Paste, etc.

Anyone familiar with the UMC metal cased bullets? Is it the same copper used to guild the Core Lokt's?


Thanks, Rob

It's probably a generic cupro-nickel guilding metal. I doubt it's plated steel. A magnet will tell you real quick.

"Metal Cased" in this instance is only using the old time description applied to Full Metal Jacket. These UMC cartridges are nothing more than normal guidling metal (97% Copper, 3% ??). I don't believe that any ammunition is being produced with Cupro-Nickel jackets anymore due to the fact that they left horrible amounts of fouling in the bore that lead to some of the "low-number" Springfields blowing up. The only difference in this ammo and normal Remington sporting ammo is the headstamp and the design, not the composition of the bullet jacket material.

Rob, a quality lapped barrel needs no breaking in. You are just wearing it out.
Butch

quote:

Originally posted by butchlambert:
Rob, a quality lapped barrel needs no breaking in. You are just wearing it out.
Butch

I always thought that but Montana recommends a break in procedure for their barrels so I assumed they're not lapped at the factory. Wrong assumption?

Rob

Rob, I have no experience with Montana barrels. I am not qualified to pass judgement on them.
Butch

quote:

I always thought that but Montana recommends a break in procedure for their barrels so I assumed they're not lapped at the factory. Wrong assumption?

I have no experience with the Montana barrel. I can't remember going to the trouble of breaking in a new custom barrel. Build, load, fire for effect.

quote:

Originally posted by Masterifleman:
"Metal Cased" in this instance is only using the old time description applied to Full Metal Jacket. These UMC cartridges are nothing more than normal guidling metal (97% Copper, 3% ??).

95% copper & 5% zinc, ranging to 90% copper & 10% zinc, depending on manufacturer and use. Current Olin listing is as Olin alloy #210, which is the 95% copper, 5% zinc version...it is included in their available "brass" alloys

Lubaloy [an Olin (Winchester)] gilding metal is reportedly a modification containing copper, zinc, and tin. It is also used by Hornady for making gas checks. Lubaloy is listed among Olin's current "Tin Brasses" or "Lubronzes")


EDITED TO UPDATE

Just looked up Lubaloy to see what latest composition is:

Two versions are listed by Olin

"Lubaloy" ,also known as Olin alloy #411, contains
91% Cu, 8% Zn, and 0.5% Sn

"Luballoy X", aka Olin alloy #425, contains 88.5% Cu, 9.5% Zn, and 2% Sn

From Montana Rifle's website...


New Barrel Break-In Procedures Thank you for purchasing your new Montana Rifleman barrel. While all of our barrels are handlapped a new barrel will shoot best if careful attention is given to proper break-in. The bore of your new barrel has “pores†in it and as you break in the barrel these “pores†are smoothed over. A smooth barrel always cleans up better than one that isn’t. Before we get started with the procedures the first thing I would like to stress DO NOT USE “Moly†coated bullets while breaking in your new barrel. The reason for this is that moly will coat the inside of your barrel and as far as I know there isn’t a cleaner out there designed to remove it. EQUIPMENT: 1. A good one piece coated cleaning rod suitable for caliber of rifle 2. Bronze bore brush suitable for caliber of rifle 3. Cotton flannel cleaning patches 4. Bore guide suitable for rifle being cleaned 5. Cleaning solvent such as Kroil , Hoppes No.9 , Break-Free or Shooter Choice & Sweets 7.62 Copper solvent BREAK-IN: 1. Clean barrel after each shot for the first 10 shots using bore guide and rod with bronze brush soaked in cleaning solvent scrub bore of rifle reapplying solvent as needed 2. Soak a patch in a good copper cleaner (Sweets 7.62) and run through barrel. If the patch comes out “blue†you have copper fouling. Keep running the copper cleaner through barrel until there is no blue. Before using any other bore cleaner ensure that you remove all of the copper cleaner from the barrel. Mixing of chemicals could have an adverse effect on the barrel. 3. Repeat the above procedures for the next 30 shots, cleaning after every 5 shot group. 4. Once you have completed the above procedures and you are no longer seeing signs of copper you can go to your normal cleaning regiment 5. But! If you are still experiencing copper fouling after going through the above procedures you might then use a Non-Embedding bore cleaning compound and cleaning rod with jag and bore guide, coat a clean patch with compound and make 10 passes through bore . Then do it again. This should solve any copper fouling problems.

I would not try to remove all the copper. I would iron in the copper that is in the barrel inclusions. If you you clean it out of the inclusions, it will continue to catch copper. If the barrel maker leaves tool marks, use JB or Isso as they are mild abrasives and won't harm the barrel.
Butch