Getting the Best from your Slugs | Precision Ballistics

Getting the Best from your Precision Ballistic Slugs

To get the best from your Precision Ballistic Slugs, read the following for some helpful tips and pointers.

(While the pictures are predominantly of the Mako, the information provided will tend to apply across all of our slugs.)

1. Start with a clean barrel

Everyone has their preferred method of barrel cleaning either a solvent soaked pad on a pull through or the little felts that get shot through
The desired end result is that you end up with no residue left on your chosen cleaning item.
Please also make sure that your barrel is suitable for shooting slugs, some considerations being, appropriate twist rate, inletting, choke tightness & length.

2. Lead your barrel

Due to the characteristics of our slugs we find that groups close up significantly when a barrel is leaded in fully.
We normally find that 10+ or so shots on average leads a barrel in, but this does vary from barrel to barrel with some needing less and others more. We have found some barrels needing 50+ shots to be fully leaded in.

The below shows the improvement by leading in on a Hatsan AT44, It's worth noting that the fliers on the last two targets was admitted mistakes on the shooters part.

(Kindly supplied by AGF\Mopane)

3. Minimise Launch Errors

Launch errors can occur for a number of reasons however one of the most common is when the slug is inserted at a slight angle. This can happen either by inserting the slug at a slight angle or when the slug is inserted from a magazine that is having issues with engaging the slug in such a way to present then at the optimum angle.
The slug needs to be inserted so that it's central axis is aligned with the barrel bore axis.

The following shows a slug inserted incorrectly at a slight angle

Note the difference in seating depth between the top and bottom.

(thanks to WolfieMac from the AGF for use of the image of a Mako in his R10)

When fired the slug travels down the barrel and on engagement with the rifling starts to rotate (or spin), as the slug is not optimally engaged i.e. the barrel bore and slug axis are not in the same plane it introduces a wobble into the slugs nose, with the central axis of the slug prescribing a progressive spiral as it rotates and moves down the barrel.

The above graphic depicts how the slug nose would spiral on engagement with the barrel rifling as it traverses down the barrel.

This wobble translates into a launch error which could then be detrimental to down range accuracy.

What is needed is for the slug to be inserted into the barrel squarely, so that the barrel bore axis and the slug central axis are aligned.

4. Magazine Interoperability

As you will have seen the accuracy of slugs is can be closely coupled to how they are inserted into the breech or barrel of the gun they are being used in.

One of the biggest influencers of how well this is accomplished is whether the slugs is loaded via a magazine, single shot loader (SSL) or manually. Lets visit these options in turn and how we view their respective merits.

For those who preference or choice is to manually load, this allows a measure of experimentation and subsequent consistency of loading on finding what suits you and your setup. Single shot loaders in our opinion are the next best thing to manually loading as this, in our experience offer the next equally consistent option to manual loading.

Finally we have the differing types of magazines and for as many manufacturers there are, there as many different magazines, these all have their strengths and weaknesses, that someone far more academic than us could write a lengthy dissertation on extolling their varying virtues, positives and negatives. However to simplify matters for now, lets break them down into two primary groups, those where the round sits freely in its own chamber or partition and those that likewise sit in their own chamber / partition but have engagement with an O-ring in some manner, to enable ease of reference lets call them "free mags" and "O-ring mags" respectively ongoing.

Both free and O-ring mags have their own positives and negatives depending on their design. In essence we have found that those "free mags" that are very loose or shall we say spacious with their allocated partition or chamber can present issues, in that this loose fitting structure allows the slug to be presented to the barrel with the nose inclined downwards. As discussed before this is detrimental to the insertion and will undoubtedly introduce a launch error and subsequent downstream inaccuracy. Worst case scenario, we have even heard of both slugs and pellets tumbling within magazines. While we are not decrying FX mags we have found their overly generous design can be detrimental and do recommend the Eaglevision magazines as a viable alternative (Eaglevision can be found here).

Regarding O-ring mags, these can present their own challenges. Historically due to the design of waisted diablo pellets, people are used to just pushing them into the magazine and allowing them to find their own natural equilibrium, where the O-ring tends to navigate to the waist of the pellet once past the diablo head. Unfortunately this methodology doesn't always work effectively with slugs.

Slugs tend to have a more pronounced nose, when not being fully seated within a magazine that utilises O-rings, we have seen one of two things occur.

1) The O-ring grips the slug by its more slender nose and so orientates the slugs nose towards the centre of the magazine, this means that on insertion we see the same bore / slug axis miss alignment that is detrimental to accuracy.

With the slug inserted squarely and with both the bore and slug central axis aligned, when fired it traverses down the barrel and on engagement with the rifling, it spins on that synchronised central axis and so has minimal if any wobble, this significantly improves flight stability and accuracy.

The above two images shows the slugs grasped by nose, with the left image showing them sitting "high" and the right image clearly shows the effect of the O-ring pushing the slug nose inward.

The below two images show the the slugs seated in the magazine. With the O-ring gripping the slug by the saddle, you can clearly see both the insertion depth on the left and how the slug noses are all more central to their respective magazine compartments.

2) The next aspect that we have encountered (albeit infrequently) is where you have an encapsulated magazine with single item insertion, where the slug is inserted the O-ring acts against the nose of the slug and pushes it up against the magazine, therefore hindering the magazines ability to rotate freely.

Both of these issues can be negated by seating the slugs in the magazine so that the O-ring effectively grips the slug by the base or saddle, therefore causing the slug to sit in a more central or "true" position with the nose more able to enter the barrel with the bore and slug axis aligned thereby facilitating accuracy.

There is one final thing to note, we have also experienced that initial shots with O-ring mags are accurate but as the magazine rotates, for some reason they go "off", in our experience we have found this to be again for one of two reasons. The O-ring is used to place tension on the round and as such, less rounds = less tension meaning the possibility of insertion errors, however the most common reason that we have seen is that the O-ring is aged, and doesn't have the elasticity it once did, simply replacing it will resolve the issue.

We hope the above guide is useful but feel free to contact us for any clarification that is required.