Freebore in a hunting rifle.

[fj40]

The twist is 1-14. I will do some measuring and post the measurements.

 

[fj40]

From base of bullet to lands 2.1625 I have been shooting nosler 55 grain ballistic tips and getting a oval hole in the paper at 100 yards.

 

[backwoods83]

You really got them out to far, I'd try some of the new 40 grn lead free nosler BT and jump then farther, they may shoot well, the regular 40 grainers are tac drivers in mine.

 

[fj40]

It's been that way since the gun was new. I've been told that a bullet should be seated one diameter in the neck .224 in this case. Tech guys at barnes bullets said that with a 1-14 twist anything heavier than 40 grains nonlead would not stabilize. He rocomended 36 grain bullets. I have been thinking of having the barrel set back and have the smith make it so at least one bullet width is in the neck. Then it would give me some versatility.

 

[backwoods83]

Yes lead free bullets are sometimes longer, but the ballistic coefficient of the 36 grn barnes varmint grenade just plain sucks.

 

[J E Custom]

Do you use a throat reamer to /and talyor throat length till max velocity with max pressure is reached?

No . I personally dont like to use throating reamers because of the potential of getting something
less than perfectly concentric.

With a complete reamer everything is true and you know exactly what your chamber
specs/dimensions are.

I never recommend building a rifle around a cartridge and bullet combination because if it
does not shoot your stuck with a T#&D . But if you build around a use and with the intention
of using different bullet styles you can all ways find a good load.

There is a practical limit to free bore and I would limit my self to 3/8 of an inch because of
velocity on impact with the rifling in a high velocity cartridge.

I have a 22 lr that has been in the family for over 60 years and has seen untold numbers of
rounds down the barrel. The throat has almost 3 inches of free bore and will still shoot sub
MOA at 50 yards .(But it is low velocity).

J E CUSTOM

 

[fj40]

J E
What would be considered the correct amount of freebore? Does it vary percartridge and or personnel experience? The 22-250 I have has enough freebore that it won't shoot well unless bullets are seat near the lands but there is very little bullet in the neck when seated that way. And the nonlead 36 grain bullets that are recommended for my 1 in 14 twist are ling for nonlead but they are still just a hair shorter than the 55 grain leaded bullets. So what is the happy medium to long freebore?

 

[J E Custom]

J E
What would be considered the correct amount of freebore? Does it vary percartridge and or personnel experience? The 22-250 I have has enough freebore that it won't shoot well unless bullets are seat near the lands but there is very little bullet in the neck when seated that way. And the nonlead 36 grain bullets that are recommended for my 1 in 14 twist are ling for nonlead but they are still just a hair shorter than the 55 grain leaded bullets. So what is the happy medium to long freebore?

I would not recommend letting the freebore exceed the body length of the bullet you want to use.
so it has not left the neck completely before engaging the rifling.

There are exceptions but that is the general rule I use if possible.

As I said earlier, I'm not sure what the point is that excessive freebore could cause problems
but there has to be a practical limit. But I do know that no freebore can cause excessive
pressure if not accounted for (Less Powder than with freebore).

A Minimum freebore would be .120 on a high pressure/magnum round but .020 thousandths
bullet jump will keep you out of trouble with standard cartriges with recommended loads.

But if you are looking for max velocity the .120 freebore would be my lower limit.

J E CUSTOM