Ned Ludd
Silver $$ Contributor
Something else you can do is to buy one box of commercial ammunition loaded with the 150 SST bullet. Hornday makes this round, there may be other brands also:
www.grafs.com
Note that this is not the "Superformance" version, which I would avoid for the purpose I am about to suggest because of its markedly higher velocity/pressure. What you can do is chronograph the commercial 150 SST ammo in your rifle, and get a feel for how well it shoots at the same time. If you like the way it performs, reproducing the velocity of the factory load with Varget will probably get you close. Then you can tweek the charge weight and seating depth and probably make your reloads a bit better than the commercial stuff.
Another aspect of having some of the commercial 150 SST ammunition [non-Superformance version] is that it is not likely to generate excessive pressure. Thus, you can gain some peace of mind as to how much velocity you can generate with your handloads without going grossly over MAX pressure. To be clear, this is not written in stone...different powders can produce different pressures to generate the same velocity, and we have no good way of knowing how the powder used to load the commercial 150 SST rounds compares to Varget. Nonetheless, it is probably a fairly safe assumption in this case.
An alternative to this approach is simply to try a few different types of commercial ammunition to find one that provides acceptable results, then use the same bullet and a similar powder to re-create a load for your setup. It's somewhat opposite of what a handloader is normally attempting to do, which is generate a solid load from scratch with specific chosen components. However, reproducing a commercial load you know shoots well is a simple way to gain more practical reloading experience, and there is nothing wrong with reverse-engineering a commercial load that shoots well.
HORNADY AMMO 308 WINCHESTER 150gr SST 20/BX 10/CS - Graf & Sons
Hornady Custom SST rifle ammunition combines the highest quality brass, primers and powders with our Super Shock Tip (SST) bullet to deliver peak performance from a factory load. The SST bullet features a polymer tip that reduces drag, improves aerodynamics and delivers a high ballistic...
www.grafs.com
Note that this is not the "Superformance" version, which I would avoid for the purpose I am about to suggest because of its markedly higher velocity/pressure. What you can do is chronograph the commercial 150 SST ammo in your rifle, and get a feel for how well it shoots at the same time. If you like the way it performs, reproducing the velocity of the factory load with Varget will probably get you close. Then you can tweek the charge weight and seating depth and probably make your reloads a bit better than the commercial stuff.
Another aspect of having some of the commercial 150 SST ammunition [non-Superformance version] is that it is not likely to generate excessive pressure. Thus, you can gain some peace of mind as to how much velocity you can generate with your handloads without going grossly over MAX pressure. To be clear, this is not written in stone...different powders can produce different pressures to generate the same velocity, and we have no good way of knowing how the powder used to load the commercial 150 SST rounds compares to Varget. Nonetheless, it is probably a fairly safe assumption in this case.
An alternative to this approach is simply to try a few different types of commercial ammunition to find one that provides acceptable results, then use the same bullet and a similar powder to re-create a load for your setup. It's somewhat opposite of what a handloader is normally attempting to do, which is generate a solid load from scratch with specific chosen components. However, reproducing a commercial load you know shoots well is a simple way to gain more practical reloading experience, and there is nothing wrong with reverse-engineering a commercial load that shoots well.
ressure signs. Case volume, chamber/throat dimensions, and seating depth play into that. As you have had some satisfactory results with 223 and seem conscientious, let’s consider a principle source of error . Several mention mediocre accuracy with the SST which matches my experience, thus a different bullet, which your barrel “likes”, is warranted. The Berger 155.5 typically gives outstanding results, as does the 155 Scenar and the 155 Sierra #2156, if your use-case is “target”. Testing your system with some known good factory ammo has been suggested and is sound. Fed GM Match 168 or 175 gr is a good starting place. Varget covers a wide spectrum in 308 so stick with it. There is a large body of knowledge here, covering general sweet spots for various projectiles using varget in various cases, which nevertheless require careful approach. Your method of working up a load requires incremental powder charges, but what increments ? 0.2 to 0.3 grain increments are appropriate for 308. You might find googling “Creighton Audette Ladder Test” to be interesting.
