Quote History Quoted:
Some mentioned it already but the 1-10 twist rate of many .308 barrels may be too fast. nylon isnt very hard and it may slip in the bore causing inaccuracy. Also powder efficiency is also dependant on bullet weight for building up pressure.
Powders that work with a 168 gr slug, might not be good with a 55 gr bullet.
I never bothered with sabots for that reason.
Buy yourself a .243 barrel and load up some hot ones if you want speed. probably be happeir with the results. Dont even need a new bolt or magazine.
View Quote
I was not able to get plastic sabots to work for me, others have, I went to making my sabots out of aluminum and that has worked for me. I I'd make a matched set male/female fine tooth spline set. Male plug of hardened steel that I press my aluminum sabots around with a collet type die. And a matching female push through die that I run my projectiles through. This solved my "slippage" issues with the rifling spin not transferring. That was after I gave up on plastic, might have worked with plastic as well ???
As to your "Just get a 243". Although I love AR-10/DPMS-308 guns chambered in 243-Win and think they are a great option. Sabots can do more, and do it with less bore wear issues.
I'm running a 338-Fed and 358-Win chambered large frame ARs fast twist bores. I can run heavy 300+ grain cast lead pills from custom molds as both subsonic or supersonic loads and the twist is just fast enough to stabilize them (which is what I originally built those guns for) but I can also run sabots with projectiles turned from 1/4" copper rod myself and also 6.5mm commercial projectiles (multiple versions of same homemade sabots with different inside & outside diameters) and can consistently acheive velocities of 4,000+ fps with projectiles that are heavier then they even make for the 243 caliber at least commercially with BCs in the 0.5-to-0.7 range. That kind of performance is something a 243-Win is NOT capable of delivering.
Sabots are a game changer that are basically a "loophole" that let you get away with legally cheating the laws of physics. They are just finicky as heck and are hard to get to work just right so you can get the performance while minimizing the accuracy problems. It takes a lot of development to find a sabot/bullet/charge combo where everything plays nice as a harmonious combination and it settles down into a consistent load that holds an acceptable group.
I'm still deep down the development rabbit hole myself. But I do have some loads that work in my specific guns that give me performance levels that could not be achieved by simply necking down to a smaller bore with the same size case body. Got to have the big bore for enough surface area to push on to maximize the internal ballistics then shed the sabot for the long thin pointy core to maximize the external ballistics. That is the inigma that the sabot attempts to solve. Bigger bore with short fat light for caliber projectile maximizes internal ballistics, small bore long slender heavy for caliber projectile maximizes external ballistics. The sabot is the only way to get both, to have your cake and eat it too.