Tag Archives: cartridges of hunting

closed cartidge crimping round and star

THE CARTRIDGE CLOSING: ROUND OR STAR?

stock, forend, shotgun

hunting womanIn the rifled guns, the cartridge case of the cartridge is closed at the apex by the bullet, which engages the neck and is stopped in the seat by means of crimping. The case of shot cartridges causes the fractionation of the charge in a column of small independent projectiles, it requires instead of being clogged at the apex by a sealing disc and a rim of stationary, or by a folding towards the center, of the same tube of cartridge case.

crimping star cartidges

The first shutter system is called “round crimp“, instead the second, the most modern, is called “star crimp.” The two systems make cartridge autonomous and transportable because they maintain firmly the structure of the internal components, protecting them from moisture of the environment. The crimp is practiced through a coil, placed in rapid rotation by a manual operation hemmer machine or by an electric motor with a low number of revolutions.

The profile of the coil varies according to the shape of the rim, the speed of rotation and the type of material that forms the tube of used casings (cardboard or plastic). The edging round with section with two folding edges rounded suits lively powders because, of equal height, has a lower resistance than the other types, while the hemming square section, where there are the corners, was abandoned because generates pressures too high and is more difficult to perform.

round crimping cartridges ammunition

In casings cardboard is practiced on a round edge on 5-7 mm of the tube, adjusting this height with respect to the resistance of the cardboard, to the weight of the shot charge, the type of wad and the liveliness of the powder. In the cartridge plastic cases the rim height ranges 6-8 mm because this material has a lower resistance at the performance being more malleable at high temperatures of firing. Too low crimps are not recommended because, offering little resistance, cause a slow and incomplete combustion of the powder with the formation of dangerous “fires long.” Regarding the star crimp, is decidedly more modern compared round crimp.

I was produced by practicing at the top of the tube 6-8 longitudinal folds, using a special coil called “engraver” (6 folds is the traditional European close, 8 folds is typically American). Following a second coil crushes these folds towards the center, in contact with the column of the shot, practicing by rotating a circular outer edge, similar to the round crimp. The height of the outer circular edge adjusts the resistance to the carrying out of the closure on the carton and on the plastic, even if the two materials require a different form of engraver and of coil crimp. A regular star crimp closure must occupy approximately 11-12 mm in free cartridge case; this measure varies according to the thickness and type of material of the tube, the height of the outer circular edge, the shape and the width of the edge section. A lightweight closure can be used to reduce the maximum pressure of the cartridge, while a very tall and narrow closure may partially compensate for a lack of clogging.

The round crimp gives an increased resistance in the phase of initial sbossolamento, but an effort of extracting total minor in comparison of star crimp. With the edge round the charge at the beginning of his movement should exert more pressure to curl the tube, then finds a minimum sliding friction within the cartridge case. With the star crimp, the charge exerts less pressure in the conduct of external light edging, while meets a higher resistance and more continuous stretching the folds of the ripple of the tube, during the passage of the shot column and of the wad.

round and star crimping ammunition

For this reason the star crimp requires a lower dose of powder. The advantage of the star crimp in hunting cartridges is the abolition of the sealing disc, which has eliminated, in part, the famous “empty pattern”; it tends to reduce the dispersion of 5%, because it gets, in the swarm of patter, the “melted “ disposition, facilitating the penetration of the air and thus improving the remaining speed of the lead. In the past, the star crimp gave certain loading problems, employing cartridge cases of poor length, voluminous powder and heavy charges, while today the problem is solved with the use of a cup obturator that allow to reduce to the minimum the height of the column of the wad.

Teresa Renda

cartridges, hunting. shooting, hunter, shotgun, lee, mec

HUNTING CARTRIDGES: ORIGINAL OR HOME-MADE?

stock, forend, shotgun

hunting womanThe cartridge is an important tool in hunting, because its operation depends on the outcome of the shot. Depending on the size, characteristics of the shotgun, kind of wild, firing range, environment and climate of the place of hunting, the hunter prefers a personal taste for a certain kind of ammunition.

This attitude is not followed by everyone, but, although in varying degrees, all of these conditions are important and determinant in the shooting.

The personal preference for the particular cartridges is, sometimes, not too rational; however, if the hunter does not have confidence in the cartridge that shoots, feels a lot of insecurity that inevitably increases the number of missed shots. Psychology and ballistics are mixed together in fact limiting the results of a day’s hunting.

Therefore, the hunter must be convinced to seek specific cartridges, and have the utmost account of an ammunition for its proven and effective performance, not for the color of the case and the box, not for the famous  name of the  powder.

It is unjustified the behavior of certain hunters who shoot regardless of any cartridge, or who uses only one type of ammunition for hunting, as otherwise it is not logical the attitude of those who are always looking a cartridge better then the previous, only to end up to blaming the cartridge in the case of “missed targets”. A little ‘balance” never hurts!

A good cartridge, if you decide to make a home loading, however, is the result of a rational loading, which claims experience on the behavior of various materials, theoretical knowledge of the basic physical laws that govern the entire phenomenon in arming explosive fire, as well that the motion of the pellets and their harmful effect on the game.

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hunting, cartridges, huntes, shootinh, shotgun

You can then decide to load their own cartridges at home, or alternatively buy in the armory.

To have so excellent ammo, just buy the original brand cartridges. In the wide range of commercial products are excellent cartridges, where performance is effective in most of the operating conditions, only by changing the number of dots in relation to the size of the wild.

But if you need cartridges suitable for atmospheric temperatures too high or low, to a very humid climate, a reed with unusual drilling, or to particular shooting situations, only the loading personnel can solve the problem. Of course sometimes it will take a while to adjust a dose for the specific hunting requirements but modern powders much more stable than those of the past, give us a hand to move quickly toward a gratifying result. And then savor the taste of retro that has accompanied our grandparents in their passion. A world to be a bit ‘with them.

Teresa Renda

Beretta, products, accessories, hunting, shooting, outdoor