The official Mike Bellm's

Bellm TCs


TC Contender, G2, Encore/ProHunter Performance Center

 





Just to save everyone a lot of wasted time and ruined frames and barrels, if you are thinking of a "short mag,", "ultra mag," or similar large diameter, high pressure cartridges,

STOP!

NOTE:
NO LARGE DIAMETER HIGH PRESSURE CARTRIDGES IN THE ENCORE..... NOTHING LARGER IN DIAMETER THAN THE "H&H" HEAD SIZE OF .300 WIN. MAG., 7MM REM. MAG, ETC.

No short mags,
No super short mags,
No compact mags,
No ultra mags,
Nothing high pressure larger in diameter than .512"-.515" at the head of the case just above the belt, the approximate diameter of the H&H headsize above the belt.

I also decline to chamber Encore barrels for the H&H head size and the still larger diameter .378 and .460 Weatherby rounds or rounds based on these cases and rounds like 7mm STW. They are just too close to the "ragged edge" of what the Encore will handle routinely.

I get requests for these daily. They are too much for the Encore and stretch the frame too much. The Encore is NOT the equivalent of any decent modern bolt action and will NOT handle the additional force exerted from the larger diameter chambers unless they are either down loaded to lower pressure levels or given essentially a long "Weatherby-style" freebore, which undermines accuracy.

By the time you degrade the large diameter cartridges to a level the Encore can routinely digest, the performance is also down to the same approximate levels of those cartridges that ARE Encore compatible.

It is a matter of pounds per square inch. The cross section of a mag chamber at .512," for example, is a larger fraction of a square inch than, say, a .308 Winchester chamber at .470" and therefore exerts more force out the back of the barrel.

I like to use the reverse analogy of your lawn mower engine and your car engine. Both use approximately the same octane fuel and the same approximate 15 to 1 air to fuel ratio, but to get MORE force to the crankshaft your car engine pistons are much larger in diameter. The pressure inside the cylinder is the same, but the surface area of the piston is greater.

In your car engine, you WANT more force. In your break open actions you must MINIMIZE the force out the "cylinder" by the "piston', the cartridge case. To do that, you stay with a smaller diameter cartridge/chamber.

Another reason NOT to chamber for the large, high pressure rounds, is the depth of the screw holes in the barrel over the chamber. A larger diameter chamber means the screw holes must be shallower in order to leave an adequate chamber wall thickness between the chamber and screw hole.
Since I am working with barrels that have already been drilled and tapped, I do not have the option of going to chamber diameters that are oversize for the Encore barrels. Increase the diameter of the chamber, and you reduce the chamber wall thickness under the scope base holes.

The "short fat" and hot mags should be reserved for bolt action guns or stronger fixed barrel single shots, NOT the Encore.

You have much greater issues to be concerned about than a few extra feet per second to plow up Mother Earth with a bigger furrow when you miss.

Focus on accuracy and dependability of the TC system first!

Then respect the gun for its worth rather than stretching things to the limit!

Shoot Smart!

Don't do dumb things.

Mike Bellm


 

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