Reloading load and bbl length?

[Cole]

I am new to the forum and to reloading. I have spent the past few months reloading and shooting .44mag in my Ruger Redhawk and Super Blackhawk. I am ready to try my luck with rifle reloading.

I have a browning .300 Win Mag. Stainless, 26" barrel. In the past I have always shot factory loaded Federal 180gn BT Barnes Triple Shock. Now this is hard to find and way too expensive. All of the load data that I am looking at in the Barnes Manuel and every other publication that I have read only shows the pressure for the barrel length of 24" which was the test length.

I also have a browning .338 Win Mag. Stainless 26" barrel.

How much more pressure builds up when shooting a 26" barrel? Does this change the charge that I should be using? I am looking to use H4831 for starters with federal brass, and magnum primers. I want to make sure I learn all I can before I start reloading rifle rounds, if i make a mistake it is going to be a $2500 loss.

[Tex S]

Start at minimum load and work you way up, looking for pressure signs the whole time.

The minimum charge for a 24'' bbl will also be okay for a 26'' bbl.

[kraigwy]

In reality, you can get buy with a bit slower burning powder with a longer barrel.

The ideal is topicke a powder that fills the case about 90% full of powder, and burns at the rate that it keeps burning while the bullet is in the barrel, and is comsumed before it leaves.

Once you reach that point you tinker with it until you get the accuracy you desire.

[Mr Odd Six]

My 26 inch varmint barrel likes IMR 4350 best.

Everything faster just destablizes the bullet.

I went for max loads off the bat. Ended up backing off 2.5 grains from max

[oldscot3]

This is a topic that I find interesting but I don't know enough to take a position. I will contribute this though...

I read a recount of an experiment once where a 30-06 was shortened an inch at time and fired. The author suggested, if I remember correctly, that most, if not all of the powder was burned within a few inches of the chamber. Bullet velocity, however, increased until it exited the muzzle presumably because it is being accelerated the whole time it is in the barrel by the pressure (expanding gases) that was generated by the burned powder. So, the shorter the barrel the slower the muzzle velocities and vice versa.

Powder choice with regard to barrel length may be a tricky thing for you. Expansion ratios are a factor and that changes between your 300 and your 338. I have a 7 x 57 with a 19 1/2" barrel. I used to try to load medium powders to get best velocity with 175 gr pills in that short barrel. It never worked for me, I get best velocity with good ole RL 22 (pretty slow stuff) and I've never seen it shoot flames.

Reload your weapons with works best for the round(work up from safe starting loads) and don't worry about the barrel length.

[SL1]

To directly answer the questions asked by the OP:

Increasing barrel length does not increase pressure. It increases velocity because there is still pressure in the barrel until the bullet exits, so the bullet is still accelerating as long as it is in the barrel. So, longer barrels give higher velocities.

For relatively small changes in barrel length in the vicinity of "normal" length for the caliber, the same powder is optimum for the "longer" and "shorter" barrels.

SL1

[Cole]

Thank you all for your help. I just finished shooting my .300 win mag. I loaded the barnes TTSX 180 BT with H4831. It seemed that I had very small amounts of yellow colored particles left over, I would assume this is unburnt poweder? Could this be from not having a sufficient crimp on the shell?

[SL1]

The small yellowish particles are unburned powder. In playing around with QuickLOAD, it appears that a case full of H4831 will burn only about 97% with this case and bullet combination. If you are using a lighter load of it, then even more may remain unburned.

SL1