27 April 2018
accuracy so best they not be bent. With the uniform thickness and concentricity of the formed case I’ve found the best method to neck size is with bushing dies. I use Redding bushing dies for this but at least 2 other makers of bushing dies are available. I’ve found that with a small assortment of different diameter bushings I can size the cases just enough to give perfect neck tension (.002&rdquo with no distortion of the bullet when seated. With a proper reaming of the sized case mouth to accept the base of the cast bullet with the Lyman minimal taper neck reamer (VLD style) the use of an M-die is also many times not necessary. With the use of the proper bushing there is no need for an expander and the Lee Universal expander will work fine to slightly flare the case mouth so the cast bullet can be easily seated if the case mouths are not reamed. The Lyman M-die of 6.5 size also works fine but the neck expander part does not touch the inside of the properly sized case necks.
The selection of what primer to use may come down, particularly these days, to what you can get. In many recent tests of primers I’ve found that most regular LR primers work equally well. Many times though a magnum or magnum type primer (such as CCIs #34s) will not work best with many powders. It is best to use regular primers with cast bullet rifle loads unless you are using very slow burning powders (slower than RL22) or most ball powders (medium and slow burners). In extensive testing with an Oehler M43 which measures external and internal ballistics including pressure I have found little to no difference between CCI 200, Federal 210, WLRs and Remington 9 1/2s with cast bullet loads using powders from Bullseye up through H4831SC. As mentioned, with slower powders or medium to slow burning ball powders, the hotter magnum type primers might be best.
I’ve read and have been told many times that primers of very low brisance such as large pistol primers can improve accuracy. Most often it goes something like this; “I was working up a HV load in my ’06 and at 2000 fps the accuracy was 4 moa. When I switched to a “such or such” low brisance primer the accuracy went back to 2 moa.” Well there is some truth to that but I’ve found through considerable that most often the 4 moa load was above the RPM threshold and when switching to a low brisance primer the velocity/RPM dropped back down to within the RPM threshold. I’ve found that there can be as much a 200+ fps different with some powders, particularly with the slow burning powders, simply by changing primers. The lowering of the velocity from 2000 fps down to the 1800 fps range and back under the RPM threshold is actually what improved the accuracy. Thus it can be said that changing primers can affect accuracy. However if we work up a load with one primer and accuracy is good then by switching to another primer is there seldom found an increase in accuracy unless we are bouncing above and below the RPM threshold. I use and always suggest to others that a good regular LR primer like the CCI, Federal, WLR or Remington will work quite well in the 6.5 Swede with most powders.
Selecting an appropriate powder for the 6.5 Swede to use with cast bullets can be confusing. Many times the selection is made based simply on the powder(s) we have available on our shelf at home at the time. This many times works out fine if we have an appropriate powder available for the velocity range we are looking for and weight of cast bullet we have. With cast bullets of 120-130 gr and a velocity of upwards of 1400 fps Unique or a similar burning rate powder will work fine. For velocities up into 1600-1800 fps then the slow burning end of the pistol powders and the fast burning end of the rifle powders work very well. Here we find 2400, 4227, 5744, 4198 and 4759 to work well.
If we want to shoot a cast bullet of this weight faster then we must really begin to look at acceleration (the time/pressure curve) that the powder will have on the cast bullet. For higher velocity loads we want to accelerate the bullet to that velocity over a longer time. For this we must look at the medium and slow burning powders. H4895, 3031, 4064, Varget, RL15, RL19, 4350 and H4831SC are the ones to try here. Slower burning powders and even some of these will reach 100% case capacity/loading density before velocities get into truly high velocity for a 6.5 Swede. Another problem with slow burning powders is erratic ignition or pressures not getting high enough for consistent powder burn. The 6.5 Swede cartridge is not one of large capacity so a balance must be reached between the weight of the cast bullet, the burning rate of the powder and consistent ignition/burn. The use of magnum type primers may help a little here with the slow burning powders that are giving 90 – 100+ loading density.
With cast bullets of 140+ gr in weight the selection of powder to use is a bit different. For the low end loads the slow burning end of the pistol powders and the fast burning end of the rifle powders work best. Here very good accuracy can be had in the 1400 – 1600 fps range. If everything is done correctly then very good accuracy up through 1800 fps can be had with those powders. However, most are finding the best success with the slower burning rifle powders. They are also finding that such very slow burning powders that give 90 – 100+ loading density are working well. Again, particularly when using such slow burning powders, the balance between loading density, velocity and consistent ignition for the velocity desired must be found.
If we are keeping the velocity of our selected cast bullet down in or under the RPM threshold then just about any quality mould of regular design will give decent accuracy. However if we are selecting a cast bullet for the 6.5 Swede at velocity/RPM above the RPM threshold then that requires some thought must be given to the selection to the design of a cast bullet. If we want the “best” accuracy out of our 6.5 Swede, even at a velocity/RPM within the RPM threshold then the same requirement for design of the cast bullet applies. The selected cast bullet must fit. It is that simple. This “fit” must be from the bottom of the case neck, in the throat, against the leade and into the bore if the selected cast bullet has a bore riding nose. If we are pushing for best accuracy and high velocity/RPM then the GC must not extend into the case below the case neck. The base/shank of the cast bullet needs all of the support it can get during acceleration. It must not be allowed to bend, rivet or get gas cut. Also important is keeping the bottom of the GC square with the centerline of the bore. If the base gets crooked then the “launch” from the muzzle will not be even and accuracy adversely affected. We must keep the cast bullet centered and concentric and the best way to do that is to keep the entire cast bullet in the case neck and the chamber throat. If you truly want to get into high velocity then a long bore riding nose unless it has a very tight fit is not conducive to accuracy at really high RPM.
Most milsurp 6.5 Swede’s have long throats. Most of these are at or slightly larger than groove diameter. The most accurate cast bullet is one that fills the throat length with the shoulder/front driving band slightly engraving on the leade. If the cast bullet has a bore riding nose then the nose should be a tight fit with some slight engraving of the nose by the lands. I have come to avoid cast bullets with long bore riding noses if I want to get into high velocity/RPM with any accuracy. The basic idea here is to get maximum support of the entire cast bullet from the base to the ogive. This will allow for minimal bending and obturation during acceleration.
Two commonly found bullet designs for the 6.5 are Lovern designs and bore riders with long noses. The common Lovern designs are Lyman’s 266455 and 266469. The common
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