Since beginning the work of experimenting with and building a few rifles for shooting sabotless bullets, It must be said that I have become spoiled! Excellent accuracy was achieved right from the start with minimal effort and at very high levels of performance. I had never shot so many nice targets in such a short period of time using a wide range of different bullet weights and types at the highest load levels possible. Elimination of the plastic sabot eliminated the associated problems and limitations of sabots and resulted in production of a rifle that is more versatile and capable of significantly higher performance levels than previously possible.
       

        What are the limitations or problems associated with plastic sabots? They are as follows:

1.    Load pressure is limited.

    In a rifle using saboted bullets, the sabot serves as the link between the bullet and the rifles bore. Since the sabot is made from plastic, it has only limited strength. If load pressure goes above certain limits, the sabot will fail and loose its ability to function with resulting poor accuracy.

2.    Accuracy at very high velocity is difficult to achieve.
     
    Accuracy at very high velocity levels is much more likely to suffer because the limited strength of the sabot may not be able to withstand torsional forces imposed by the barrels rifling.

3.    Barrel rifling twist rate which determines what weight and speed bullets can be shot is limited.

    If a rifle barrels rifling twist rate is too fast, it becomes difficult if not impossible to shoot a saboted bullet at highest velocity because the soft plastic sabot will not withstand the high shear / torsional forces imposed by the fast twist rifling. If shooting plastic saboted bullets from a barrel with fast rifling twist then velocities must be slower to achieve accuracy.
        If high velocity is to be achieved with good accuracy using saboted bullets then the barrel rifling twist must be slower. The use of the slower twist rate limits the weight of bullets that can be shot. If the longest and heaviest bullets are to be shot at high velocity then, faster twist rifling must be used which eliminates the possibility of using plastic sabots if expecting accurate results.

4.    Plastic sabots are affected greatly by temperature.

        If best accuracy is to be obtained when shooting saboted bullets, then careful attention must be paid to temperature. As barrel temperatures rise the plastic sabot gets softer and loses strength which degrades accuracy. That means that a significant waiting period between shots is required to avoid overheating the rifles barrel if best accuracy is desired. Also, hot weather makes things even worse even to the point that a load may require considerable reduction if any accurate shooting is to be done.


        The advantages gained through the use of sabotless bullets are therefore as follows:

1.    There is no limit to the "safe" load pressure that can be used because an unsaboted solid copper or copper jacketed bullet can easily withstand maximum safe working pressures without blow-out or other failure.

2.    Unsaboted solid copper or copper jacketed bullets are strong enough to withstand any obtainable velocity and still give excellent accuracy.

3.    Any sufficiently fast rifling twist can be used when shooting sabotless copper or copper jacketed bullets because the bullet material strength is more than sufficient to withstand torsional forces.

4.    Temperature is of much less concern when shooting sabotless bullets and great accuracy is still obtainable without long waits for barrel cool down. Hot weather is also of little concern.


        What are some disadvantages associated with shooting sabotless bullets?

    As with anything, there are always some negatives that need to be dealt with. One disadvantage is as follows.

1.    The bullet size as related to barrel bore size is very critical. If the bullet is too loose a fit in the barrel bore, misfires or poor ignition with inconsistent results and poor accuracy will result. If the bullet is too tight then loading will be difficult if not impossible. Many bullets may require resizing to obtain the proper fit. A bullet sizing die or dies are provided with Swing-Lock sabotless rifles to assure the customer can obtain bullets to the exact size needed. Also, future Swing-Lock rifles will use precision barrels of the proper size which will allow the use of some already commercially available bullets ( e.g. Parker Ballistic Extreme ) which will fit properly without the need for resizing. Bullet sizing dies will still be provided to allow use of other bullets as well.

        To be fair, it should be mentioned that the above disadvantage regarding sabotless bullets brings to light an advantage with regards to saboted bullets which is the fact that the barrel bore to saboted bullet fit is not nearly so critical. The soft plastic sabot allows for errors which cannot be tolerated when shooting sabotless bullets.

    Many bullets such as those shown above which are really very desirable to shoot must first be sized to the exact correct size before they can properly be loaded. For bullets to load properly, after sizing they will measure approximately .0002 to .0003In. over the rifles bore diameter. If bullets are of proper size, they will load with approximately the same force as a snug fitting load using a sabot. Dies provided with Swing-Lock rifles are custom made for the rifle to produce bullets to the correct size. Future rifles will also be able to use certain commercially available bullets ( e.g. Parker Ballistic Extreme ) without the need for resizing. Sizing dies will still be provided to allow the use of other bullets.
    When sizing .458 diameter bullets, two dies are used. the first die sizes the bullet down approximately half way while the other die brings the bullet to final size. The photo below, shows a typical bullet sizing die and brass punch which is used in a standard loading press.