Reloading for a short barrel

[geraldgee]

I recently bought a M700 .223 with a 16.5" barrel. I've had it out once and can already tell I'm gonna like it...especially after I swap out the trigger and stock. Nonetheless, I have questions that I need to ask of the experts:
How far up the barrel does a .223 bullet travel up the barrel until all the powder is completely ignited and burned?
How much does the burn rate of the powder play into this, if any?
Is there ever the danger that a particular powder NOT be entirely ignited by the time a bullet traveled 16.5"?
And finally, is there a formula that can be applied to powder that would answer the questions I just posed and can someone provide that formula?

Thanks for your help

Gerald

 

[UrbanSi]

I run multiple barrels in .308, the shortest being 15" and the longest being 26", there is a 20" and a 22" somewhere in there.

Most of my loads are with W-748 and IMR-4895.

The general consensus from most is that for every 1" you cut off, you lose about 20-30 FPS. It holds true in almost all my guns under 22"

You might have incomplete burn depending on the load, there is a lot to factor in.

It might help if you list your load and if possible any chrono data.

Some people look for excessive flash, which I find inconclusive as different powders use different flash suppressants. Its like people who want
to know what powder is being shot from factory loadings.

With .223 increasing crimp will have a few different results. It may lead to more complete burn but it may effect accuracy. A chronograph will
surely come in handy here.

Changing powder/primers will play a role in what combination works in your particular barrel length. If my ES and SD are in line while achieving
the accuracy I want, I could honestly care less about some unburnt powder (if in fact thats the case)

 

[thefitter]

Varies
Alot
yes, but it's not a danger just inefficient
Get a reloading manual and start with recommended loads for the bullets you want to use

But I'm no expert, have fun.

 

[ZiaHunter]

On a shorter barrel you will be better off with powders on the faster side of the scale. The best way is to check with Quick Load which will give you and estimate of the percent of powder burned.

 

[Jedi]

Quick load will answer all your questions

 

[Deadshot2]

Look at loads that are designed for the AR-15's to begin with. Barrel lengths are in the 16-20" range for the most part. While loads for these rifles also take into consideration the gas port pressures, they will make a good starting point for your bolt action loads.

Faster burn rate, yes but the real test is what happens out on the target.

Powders I'd start with (assuming they are available) are AA2230, BL-C(2), H335, or the relatively new CFE223. The rest is up to developing a load that works best in your rifle, meeting your needs.

 

[korykhunter]

If your shootin light bullets N120 burns very fast also, but I only use it behind a 40gr Vmax.