general reloading question

[onegoodshot]

So the published load data for many cartridges has to be on the weak side because of liability issues with idiots making loads for guns that can't handle them. Then you have the ruger, t/c, freedom arms data.

I'm not a speed junkie, so this is purely a question of "why?".

Try to follow me. I know I'm not articulating the question just right but.....

Say you have a Ruger 41 mag with a 7.5" barrel. Few published 41 loads fill up the case anyway. Even using the 265 lasercast, I still have case capacity left. Some guys here have made the 41 mag "long" chambers. What/How does the extra brass length do?? Is it so you can use MORE of a SLOWER burning powder or heavier bullets? When dose the barrel length come into play with powder burn rate?

[subsonic]

You ask good questions.

The most popular and arguably best powder for the job is H110(296). This powder doesn't like real low pressure or air space. It's also fairly hard to light, so having it firmly sitting against the flash hole is good too.

In your example, we'll take a .41 mag and load it to 1.590", SAAMI max OAL.
Lets guess it takes 20gr of H110 to make 1200fps with whatever bullet we're using. This is all just numbers grabbed from the air...

Seat it out to 1.700" and it will take more powder to reach 1200fps, but it will also hit 1200fps at a slightly lower pressure, and with more air space in the case.

What have you gained? Some will say you can add a little more powder to reach the same pressure and gain some velocity, which is true. But what load data are you going to use?

Do you have a pressure gauge to make sure you're not exceeding the max?

Will you loose more than you gained by reducing bullet pull?

Will accuracy and consistency suffer because of the added airspace in the case?

I'm not a fan of having mor than half the bullet or boolit out of the case....

[magnumwheelman]

I have a S&W 610 ( revolver ) originally chambered for 40 S&W, & 10mm... I had the chambers deepened to fit the 10mm magnum all 3 cartridges reach different velocities, so I'm not totally understanding the question...

also have a 357 Maximum, 38 special, 357 magnum, & 357 Maximum all fire in the revolver, same as the 10 Mag, they all progressively reach higher velocities the more case volume ( longer ) they are

in some cases, the longer case length allows the longer bullets to seat deeper

[mark]

Sept 4, 2013 14:55:20 GMT -5 onegoodshot said:

So the published load data for many cartridges has to be on the weak side because of liability issues with idiots making loads for guns that can't handle them....

Read post #7 here smith-wessonforum.com/reloading/163307-changes-231-charges.html from Mike Daly of Hodgdon. He explains this part of your post. As for the rest of your question, I agree with subsonic. I will add that in my Redhawk (44 mag), if opt for a longer and hotter load (using 110/296), I get better accuracy. I can guess why but the proof is in the target.
Mark

[onegoodshot]

Its the physics of the air space that eludes me. I'll stick to counting pills but I certainly thank you for your input. Using the 38/357 example. In a strong gun (ruger), you can load 38's to 357 mag power and still have a smaller framed gun. Even the factory +P loads come close to factory 357's.

When I was playing around with 10mm contenders many years ago, I did load ramps with a 10" and 14" 10MM and a 14" 10mm Magnum. Using factory ammo, the barrel length played little role. With my reloads, you could tell the difference in barrel length vs the various loads used.
Using the 10mm Magnum barrel I could push a 135gr Nosler HP so fast that it shed the jackets.

[seancass]

I'm not the most experienced , but i'll try contribute.

If you have extra case capacity And you want more velocity, look for a slower powder. If you are already using h110/296 i don't have a better suggestion! Someone else here might.

As to loading longer, it will generally decrease pressures, but some powders might not like that. The same amount of powder in a larger case will generally slow things down. Some prefer shorter cases full of powder. Others want as much powder and bullet as possible. You may be able to produce identical results either way.

I'm looking forward to reading more in this thread.

[mohillbilly]

I have a Dan Wesson 445 Supermag/max with a longer case than a 44 mag case . It was designed to shoot 200 fps faster than 44 mag at the same pressure . I have , I think found a better powder than 110/296 as , AA 1680 or old surplus 680 . As far as air space , forget that and look at how full the case is. The fuller the case, the powder will not "lay down" and that will give even ignition and burn like a cigarette (end burning ) . This will give you better shot deviation . A side benefit is safety , in that if you should double powder charge it would spill out , saving your gun ,hands ,eyes , and fellow gunners , as well as passerby s . Full or nearly full cases will cost more to load , more accurate in the long haul ( not identical accuracy ,better accuracy shot to shot , at the same speed , or better with a longer case and more slower powder ) , safer in double charge, small charges can be so small that laying in the side of the case it is possible to get a squib load , sticking a slug in the barrel and shooting again can spell disaster , ringed barrels and blown guns . hard to light powders down loaded can do this too. The 38/357 example stinks IF you are loading to standard OAL with the same slug and powder and charge weight . You are depending on Rugers safety factor then . Unless you have an old model three screw ( smaller frame ) , the same frame is on a super black hawk (44mag ) is on a .357 new model . The 357 would have a greater safety factor than the 44 mag as both guns are the same size/steel/hardening on the outside, but the holes are bigger on the 44 and the 357 weighs more because it has more steel and an even better safety factor ... BUT do YOU want to bet on Rugers safety factors ?? AND if you do is it possible to put those high power loads in an other gun that may NOT have a high a safty factor ? Ah those 38+p loads can be NEARLY as fast with the same slug but the factory loading could be powder that you have no access to . Heck even a different primer/batch could cause a kaboom . Or sometimes those loadings cheat with a much lighter slug . When it comes to barrel length it will tell you when you are loading too slow a powder , as there will be excessive flash,noise, and unburned powder . That will not hurt the gun but it will hurt your ears and wasteful on powder . As I remember , with the same loads, a 10" barrel was cut an inch at a time , with a loss of about 200 FPS per inch cut off . Remember it is not the loudest , fastest that make the best loads . IT is hitting what you are aiming at that IS important .... WHY are there different loading levels ? Short answer is some of these old chamberings were designed for black powder and wrought iron guns , some for fluid/nickel steel and some for super steels or stronger engineered /built safety factors , for higher performance . Don't put 454 Cassul loads (even if it would go in) into your 1873/1909 Colts , or your 357 max,mag,38 special into a 1902/04 38 long Colt . Those old guns have not the steel quality,engineering,safety factors .....Then again specs have changed as well said 1873/1909 Colts have .454 barrels or bigger ,and balloon head cases . .38 long Colts Had .401 barrels and balloon cases as well ...... Then inside or outside lubed /heeled boolits changed todays specs as well ...