5Redman8,
Oh the joys of handloading,
First off, if your rifle is built on a strong modern action and your data that lists 2400 fps as a safe top velocity, there are some things you can do to get more velocity.
It is very common to use published data and when you actually test in your rifle, velocities are well short frm those of the tested data.
This is for several reasons. THe main reason is that many companies, powder and bullet makers that provide data often use pressure barrels which have min spec, basically match grade chambers and the barrels are often match quality as well with much tighter bore diameters then what we have on many standard grade barrels.
What this does is produce more velocity and presssure for a give charge of powder then in a looser chamber in a standard barrel. THis is why your velocity is lower and why this is common.
Seating your bullets out longer also will reduce pressure and velocity unless you are seating into the lands and then pressures can increase.
Basically what you are doing seating the bullet out farther, especially in a medium bore and big bore rounds is increasing the case capacity of the round which will result in less velocity unless you correct your powder charge for the increased case volume.
Always keep in mind that velocity is a product of pressure and time. THese are at least the major componants to velocity, sure bore finish and ambiant temps have some influence but by amd large you get a certain velocity from generating a certain amount of pressure behind a bullet for a certain amount of time(the time it take the bullet to travel down teh bore).
This is relatively constant from one rifle to another as long as the bore is in good condition and the bullets are seated relatively the same to the lands.
What this means is that if a load data manual lists 2400 fps with a given bullet out of a test barrel, they are generating X amount of energy to accomplish this.
You will need to generate the same X amount of energy to get the sme results. With the looser chamber and possibly looser bore, and with your seating the bullets out longer, it will take more powder to generate the same amount of pressure in your rifle compared to the test rifle.
As long as you are alert to the pressure signs and make sure you stay in a safe range, it is perfectly safe to increase your powder charge to reach the velocities listed in the load manuals.
Keep in mind to check the barrel length the tests data was generated in. If they use a 26" barrel and you have a 22" on your rifle, DO NOT EXPECT TO GET THE SAME VELOCITY because it will take much more pressure to do so in your shorter barrel.
Also, you may not get the exact velocity without some pressure problems, keep this in mind at all times when increasing your load and velocity.
Where youare getting 200-300 fps less, you should be able to easily get within 100 fps safely as long as your barrel lengths are real similiar. If you are using a shorter barrel, take 30 fps off for each inch and refigure your target velocity.
Again, all this only should be used in a modern strong action. If you happen to have a small ring mauser in this caliber which there should not be but I have seen smiths do it, leave your loads where they are.
If you are using a quality M98 action or any modern commercial action, you should be able to increase your velocity to be very close to published velocities.
GO slow, increase in 1/2 gr levels in a case with this volume and do not get greedy. Watch for pressure signs and at the first hint of them, back off by enough to make then go away.
There are also some rifles that will not show pressure signs in the conventional way. My full custom rifles that I build are so tight in the chamber and action specs that you can not read pressure off a case reliably with conventional measurements and get an accurate idea of your pressures.
Also, soem factory rifles will produce velocities far over listed specs with no pressure signs at all, this does not mean that they are not far over pressured.
USe velocity as your guide and when you reach listed velocity stop because to get that velocity you have to generate the pressure as well. Even if you have no pressure signs, STOP!
As far as velocity drop to the chronograph, it varies from 10 to 20 fps in most cases, not really enough to worry about.
Hope this helps some,
Good Shooting!!!
Kirby Allen(50)
