Icon Logo Gun Mart

Reloading: Burning issues

Reloading: Burning issues

It’s almost a year since I contacted Nigel Cole Hawkins, the UK distributor for Reload Swiss propellants and convinced him to ship me some samples for review. A few months later I started work on a revised long (‘ish) range target load in .308 but it has taken much longer than planned. So, let’s use this as an article on cartridge development.

Need to know

To start with we need to know a bit about the rifle to make sensible bullet choices. In my case the rifling twist is 1:14, OK for medium weight match bullets in the 140 to 170-grain range. Barrel length and chamber form are also important. My choice of the Sierra 155-grain HPBT Palma Match sits pretty much in the middle. Brass started as brand new standard Lapua .308 Win. (I’ve yet to do a ‘head to head’ comparison with the reduced flash hole diameter Palma Match Lapua brass – although my earlier experiments with changed flash hole diameters have convinced me that this can be an important ammo tuning feature). Primers are Federal 210 and the powder choices are all from Reload Swiss, RS40, RS50, RS52 and RS60.

To condition the new Lapua it was initially loaded with 150-grain PPU pills atop 40-grains of IMR 4895 (my current 308 ‘default’) and used for shorter range plinking. The cases were then de-primed, ultrasonically cleaned, tumbled and neck sized ready for use.

 

The need for speed

Ammo development requires a chronograph. From my Caldwell Ballistic Precision Premium kit to my Oehler 43 Mini Lab, the choice is huge. Basically, they are posh stop watches measuring the time of flight of the bullet over an accurately controlled distance. They turn this data into speed in either feet or metres per second (fps/mps). Many also offer a suite of extra features such as the storage of a string of velocity data, the ability to isolate the highest and lowest velocities from the string, calculate the average velocity of the string and determine a vital factor called the Standard Deviation (S.D.). Newer models such as my budget Caldwell also offer downloadable apps that enable the chrono to talk to your smart phone, tablet or computer. Whist the timing component in modern chrono’s are based and around quartz timing devices and is therefore extremely precise, the pitch of the sensors represents a potential variable. It is therefore a good idea to run a comparative test of your new chrono with another of known performance before taking the readings as accurate. My Caldwell seems to read just under 0.2% low based upon comparison with proof data from the same rifle, but that’s more than good enough!

 

Powder impressions

story continues below...

Cracking the lids on the Reload Swiss powders reveals them all to be relatively fine, dark grey extruded rod designs. Lose the labels off the tubs and you would be hard pressed to identify the individual types. Metering qualities proved to be extremely good. Batch weighing the bullets gave extremes of 154.6 and 155.3, par for the course with Sierra products. A total of 28 x 10 bullet batches, each with less than a 1/10-grain variation, were obtained from the three boxes. That gave me seven batches per powder type. The Swiss reload manual did not quote data for the chosen pill, leaving me to interpolate between the 150 and 168-grain data. The seven loads for each type were incrementally spread between the quoted start and max figures from the manual. From previous experience with the IMR 4895-based Palma ammo my default COL was 2.792”, a jump of 0.018”. Bullet runout/concentricity of the assemblies was checked on my Sinclair gauge.

 

Best sd of 6 with more to come

The barrel was scrubbed after each 10-round batch. Throughout the various tests the RS52 felt the best, closely followed by RS40, borne out by the ES and SD figures. Given range limitations I was primarily interested in getting the lowest 10 round batch SD with a view to later attempts at group accurising around those loads. The best SD were with 41.7-grains of RS40 and 45.6 of RS52, both recording a very impressive 6. The RS52 average was 2629 fps with absolutely no signs of pressure, indicating that there is almost certainly more to come from further increases in the charge weight beyond those interpolated from the max figures in the manual.

 

I’m a believer

Yes, I’m confident that I’m on the trail of an improved recipe based upon Reload Swiss RS52. Not only does it meter extremely well, it’s clean to use. Other scribes have likened it to Varget and I see no reason to disagree. As the new kids on the block I must say that the range of Reload Swiss powders has a great deal to offer both hunting and target shooting reloaders. More RS reloading experiments will follow, as will a ‘beyond the data’ conclusion to this test. Take a peek at the UK RS web site for further details about their products: - http://www.propellants.co.uk/

 

Bullet points

As a responsible scribe, I always endeavour to source at least one professional and independent corroboration of any legal issue that I cover. In the ‘Hollow Victory’ piece on the new law changes in bullet types I sought the wisdom of a couple of Firearms Officers as well as that of the advisor to a major shooting organisation. With regard to the use of ‘expanding’ projectiles for rifle target shooting I failed to get a consensus and therefore erred towards the negative advice. A couple of readers have challenged that interpretation, leading to me making further enquiries. Whilst the Home Office Guidance Notes are unambiguous, the actual legislation is drafted in a prescriptive manner that is open to interpretation. Following a written opinion from the highest authority I can now confirm that we ARE able to use ‘expanding’ designs for rifle target shooting purposes. However, some range standing orders still ban the use of hollow point projectiles so check before you shoot. Mea culpa.

Arrow