160 Geelslang Avenue, Kameelfontein, Roodeplaat, Pretoria
+27 62 852 4311
info@accugun.co.za

Match Barrels

Different Barrel Making Techniques

Cut Rifled Barrels

The art of making a cut rifled barrel is very old and has mostly been replaced by new – but not necessarily better or faster – technology. All barrels start with a precise hole being drilled, which is referred to as gun drilling. Normally the hole is drilled slightly smaller than the actual diameter, and then reamed or honed to final size. In the case of cut rifled barrels, each groove is cut by means of a hook cutter. The cutter cuts 1/10000 of an inch at a time, thereafter the barrel is indexed to the next groove and cut. This process repeats itself until all the grooves are cut to final size. The advantage of this method is that no stress is induced back into the metal. The grooves can be cut to the correct depth, resulting in increased barrel life.
Barrel Contours

Special contours available on request. Please contact us.

MATCH CONTOURS – VARMINT / TARGET

The key to an accurate firearm is consistency. Getting everything to happen the same way for every shot is key to producing small groupings, and there are a large number of issues to be addressed in achieving an accurate firearm.

Usability

Enhancements that give the shooter a firmer and more consistent hold on the firearm, as well as a more consistent trigger pull.

Tolerances

Parts that better fit together will shift less, or shift more consistently, under recoil. Rifle bedding is one of the most common practices of such accurizing procedure.

MATCH CONTOUR – PALMA

Between a straight taper and a Palma taper barrel of the same weight, it comes down to balance. More of the mass of the Palma taper is toward the shank end which moves the balance back towards the action. That brings the balance of the rifle back closer to the shooter which makes the rifle “feel” better balanced in positional shooting.

Harmonics

The act of firing a gun generates a rapid pressure increase within the barrel bore, causing the barrel to resonate and vibrate in a whip-like fashion.

Projectile propulsion consistency

Firearms rely purely on the powder within a cartridge to provide propulsive force, and any slight variations in powder load and rate of combustion will affect the internal ballistics of the gun, even if the projectile weights and shape are the same.

Breaking-in 

Any premium barrel that has been drilled and reamed will show reamer marks that are directly across the direction in which the bullet travels. It is essential to properly finish the barrel, such as your Mojet barrel. The direction of the finishing is the same as that of the bullet’s trajectory, therefore fouling is minimal. The function of the break in the procedure is to break in the throat area off the barrel. When the barrel is chambered, the reamer leaves marks perpendicular to the lands. When the bullet is fired, due to high pressure and temperature the copper dust is vaporised in the gas and carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited into the bore though this might fool one to believe that the barrel is fouling, it is in fact caused by the throat. The copper needs to be removed to prevent build-up. As the throat gets polished, the fouling will be reduced which is also an indication that the barrel is broken in.

Cleaning 

Cleaning A good quality cleaning rod with a bore guide is essential to clean the barrel properly. We use a Barrel Magic to clean our barrels, as it does not necessitate the use of a brass brush. A soaked patch with barrel magic left for a few minutes and followed by a couple of patches until clean is all it takes. Always clean from the breach if possible. Often damage is done by improper cleaning, more than shooting the rifle. It is vital to prevent damage to the crown, as this will compromise accuracy. A barrel with a worn or damaged crown can be re-crowned and accuracy will usually return. Abrasive Cleaners work well. They do not damage the bore, they clean all types of fouling (copper powder, lead, plastic), and they have the added advantage of polishing the throat both in “break-in” and later when the throat begins to roughen from the rounds fired. There are two basic types of bore cleaners – chemical and abrasive. Chemical cleaners are usually a blend of various ingredients including oils and ammonia that attack the copper. Abrasive cleaners generally contains no chemicals and are oil, wax, or grease based with an extremely fine abrasive such as chalk, clay, or gypsum. They clean by chemically removing the fouling. Both are good, and we feel that neither will damage the bore when used properly. A jag with a patch wrapped around it also works well. Apply the cleaner and begin scrubbing in short, fast strokes of about two to four inches in length. Concentrate most of the strokes in the throat area , decreasing the number as you go towards the muzzle. Make a few full length passes while avoiding exiting the muzzle completely, but do partially exit for about six strokes. You can avoid accidently exiting by mounting the rifle in a vice or holder of sorts and blocking the rod at the muzzle with the wall, or something to keep it from completely exiting. A recommended starting point would be 3×1 shot cycles, followed by 3×3 shot cycles and 3×5 shot cycles. Observe when the fouling reduces and shoot as normal. We have found 25 to 30 shots before accuracy will start to suffer, however it is best to keep the barrel clean.