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egoas
Hunting for living

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# Gesendet: 2 Mai 2011 22:45


egidijus1
tai dar gerai kad vamzdzio ilgi parasytum savo t3.


____________________________________________________
Lietuva- turime didingą praeitį, tragišką dabartį ir miglotą ateitį.

egidijus1
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# Gesendet: 3 Mai 2011 00:23


600mm.varmint stainless LH.

egidijus1
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# Gesendet: 3 Mai 2011 00:25


as jo tikrai niekam nekisu,bet jei nori i asmenine parasyk e.pasto adr. Atsiusiu keleta foto is saudyklos.

egidijus1
Medžiotojas

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# Gesendet: 3 Mai 2011 00:26


600mm.varmint stainless LH.

egoas
Hunting for living

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# Gesendet: 3 Mai 2011 00:27 - Edited by: egoas


as sautuva tai jau turiu isirinkes, tik va jie turi abieju vamzdziu, tai nzn kuri imti. na saudykla tai kitas dalykas. nes as renkuosi net ne varmint.

____________________________________________________
Lietuva- turime didingą praeitį, tragišką dabartį ir miglotą ateitį.

egidijus1
Medžiotojas

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# Gesendet: 3 Mai 2011 08:46


jei imi net ne varmint ir vien tik medzioklei tai tada imti trumpu vamzdziu ir patogiau ir smagiau atrodo.Medziokleje tau tikrai jo uzteks ir dar neisnaudosi visu galimybiu.taikliu suviu

mancius1
Medžiotojas

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# Gesendet: 3 Mai 2011 12:03


Tai gal atsiliepsit kas turit trumpą 51cm vamzdį? vis dar bandau išsiaiškint, kiek sumažėja kulkos greitis palyginus su 60cm.

H13
Hunting forever

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# Gesendet: 3 Mai 2011 13:57


Pas mane Mauseris su 51 cm vamzdziu.
Kulkos greitis teoriskai turetu nukristi nuo 5 iki 7%. Labai daug niuansu.
Kaip yra is tikruju - nematavau.

Nepataiko ne šautuvas, o medziotojas

mancius1
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# Gesendet: 3 Mai 2011 14:33 - Edited by: mancius1


Aha, dar pasiknisau, tai krūvą info radau angliškai, tai irgi nuomonė, kad .308 20 ir 24 colių vamzdžiams 180granų kulkai greičio mažėjimas apie 6%...
bet vis tiek klaustukų lieka, nes bent pagal kritimą ant 200 ir 300m man gaunasi, kad mažėja daugiau %, bet dar reiks laukuose paeksperimentuot..

zilvez
Medžiotojas

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# Gesendet: 3 Mai 2011 15:05


mancius1
į tavo minėtus klausymus gali atsakyti Klaipėdos Oksalo žmogus, nežinau nei vardo, nei tel.(teks pačiam susirast), buvo jis ir idomiai pasidalino savo žiniomis Normos testavime Šiauliuose, turi programėle ir gali suskaičiuoti greitį, džaulius su ivairaus ilgio vamzdžiais, žiurint į normos šaudmenų katalogą - ten duomenys, kaip minėjo oksalietis, yra su standartiniu vamzdžiu, o standartą skaičiuoja sakė 65cm. tad sėkmės renkantis, aš pritariu mancius1 mintims, medžioklėj tikrai skirtumo didelio nebus

Anonimas


# Gesendet: 3 Mai 2011 16:18


mancius1
Koks tu eksperimentu tikslas ir pagal kokia metodika eksperimentuosi?

mancius1
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# Gesendet: 3 Mai 2011 16:27


tai čia daugiau sau nusistatyt kiek MOA kritimas skirtingais atstumais, nes nežinant pradinio greičio sudėtinga balistiniu kalkuliatorium pasinaudot. paskutinį kartą išbandžiau tik 200m (3,4MOA) ir 300m (7,5MOA) atstumus, kada prie progos iš toliau pašaudysiu. turėdamas daugiau informacijos, jau galėsiu balistiniam kalkuliatoriuje "pritraukti' greitį, tada jau skitingom oro sąlygom persiskaičiuot...

dula
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# Gesendet: 3 Mai 2011 18:24 - Edited by: dula


Jei tikėti teorija, tai .308 šoviniui (750m/s) centimetro reikšmė 1,2 m/s, Tai 4 coliai bus beveik 10 cm, o tai tik kiek daugiau nei 1 procentas.
"kaip minėjo oksalietis, yra su standartiniu vamzdžiu, o standartą skaičiuoja sakė 65cm." labai keisti standartai Oksalyje.

PAKO


# Gesendet: 4 Mai 2011 10:31


1fps=0.3048 m/s
1 inch'as = 2.54 cm


Barrel length, accuracy and ballistics

It is worth mentioning that a longer barrel is not inherently more accurate than a short barrel. Intrinsic accuracy is a matter of quality, not length. However, a longer barrel is generally better in terms of practical accuracy, because a longer and therefore heavier barrel (within reason) is easier to hold relatively steady from unsupported positions; thus it is easier to shoot a long barreled rifle accurately.

The length of the rifle barrel has a direct influence on the velocity obtained from the cartridge for which it is chambered. Ballistically, for centerfire calibers, longer is usually better. However, for carrying, handling and maneuvering in close quarters (like thick brush or getting in and out of vehicles), shorter is usually better. Some sort of compromise must therefore be reached.

Very long 27-30 inch barrels are seldom seen these days on repeating hunting rifles, although they are still occasionally found on single shot hunting rifles and target rifles. The longest barrels usually seen on hunting rifles today are 26 inches in length.

26 inch barrels are usually found on rifles chambered for high velocity magnum cartridges. A long barrel is required to burn the large amounts of slow burning powder used in this type of cartridge. Unfortunately, most repeating rifles with 26 inch barrels balance too far forward; they are muzzle heavy and slow to swing. The long barrel seems to hang up on every limb and outcropping of rock in the area and a hunting rifle so equipped can be very awkward carry in steep terrain.

For this reason, many magnum rifles now come with 24 inch barrels, which sacrifice some of the magnum's velocity. 24 inches is about the minimum barrel length practical for most magnum cartridges. Cut a magnum's barrel down to 22 inches and the muzzle blast and flash become intimidating. Also, magnum cartridges such as the .264 Win. or 7mm Rem. lose so much velocity in a 22 inch barrel that they show little ballistic advantage over standard calibers like the .270 or .280.

The typical barrel length for a repeating hunting rifle chambered for high intensity cartridges, such as the .243, .270, .308, or .30-06, is 22-24 inches. These are useful all-around barrel lengths for such cartridges. The highest velocity standard cartridges (.243, .25-06, .270 Win.), which achieve muzzle velocities around 3000 fps, are at their best in a 24 inch barrel and 24 inches is the SAAMI standard for almost all American centerfire rifle calibers. However, for cartridges such as the .257 Roberts, 6.5x55, 7mm-08, .308 Win., .30-06, .338 Federal, .35 Whelen and .350 Rem. Mag., which typically operate at 2500-2800 fps, the velocity loss in a 22 inch barrel is not extreme and a rifle with a barrel of this length usually balances and swings well.

Cartridges with smaller cases that operate at lower velocity, such as all .22 Rimfire cartridges, the .30-30, .32 Special, .35 Rem. and similar numbers, do well in 20-22 inch barrels. The very popular carbine versions of classic lever action rifles like the Winchester 94 and Marlin 336 usually come with 20 inch barrels. These short rifles ride well in a saddle scabbard, are easy to carry in rugged terrain and handle very fast in close quarters. Because they are light rifles, they balance well with a 20 inch barrel. Muzzle blast from these cartridges in a 20 inch barrel is less severe than from the larger high intensity cartridges in a 22 inch barrel.

Combine a high intensity cartridge with a 20 inch barrel, however, and the velocity drops noticeably while the blast becomes annoying. Still, a rifle with a 20 inch barrel, chambered for short action cartridges like the 7mm-08, .308 and .358 Win., makes a very effective mountain or woods rifle. These cartridges retain enough velocity in a 20 inch barrel for medium range shooting and the stubby barrel is less likely than longer tubes to get hung up on branches, overhanging ledges, rocky outcroppings and so forth.

To my mind it is hard to justify barrels shorter than 20 inches for any purpose. I have owned rifles with 18-19 inch barrels and in every case I wished that they had come with at least a 20 inch barrel. Very short barrels of standard contour (not bull barrels) tend to make the rifle muzzle light and unsteady to hold and swing. I like a rifle to balance between my hands, not toward the butt. Even .22 rimfire rifles balance better with 20-22 inch barrels, although in this instance the longer barrel has no ballistic advantage, since the .22 LR cartridge burns all of of its powder in about 16 inches. Very short barrels also increase the muzzle blast from high intensity cartridges to very annoying levels and the velocity loss is excessive.

Velocity loss (or gain)

It is worth noting that the velocity figures published in ammunition brochures and reloading manuals are sometimes taken in barrels different in length from those supplied on many rifles. I have seen various estimates of how much velocity is lost (or gained) when a barrel is not the same length as the test barrel in which a cartridge was chronographed. Here are some of them.

The 2001 Edition of the Shooter's Bible states, in the introduction to the Centerfire Rifle Ballistics section, "Barrel length affects velocity, and at various rates depending on the load. As a rule, figure 50 fps per inch of barrel, plus or minus, if your barrel is longer or shorter than 22 inches." However, they do not say what category of load to which this 50 fps average pertains.

Jack O'Connor wrote in The Rifle Book that, "The barrel shorter than standard has a velocity loss which averages about 25 foot-seconds for every inch cut off the barrel. Likewise, there is a velocity gain with a longer barrel." He went on to illustrate this using a .30-06 rifle shooting 180 grain bullets as an example, so his estimate was obviously for rifles in that general performance class.

Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:

MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.


The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:

For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.

The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:

The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.

For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:

The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
The average loss for the .30-06/180 grain bullet was 15 fps per inch.
The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.

After a bunch of disclaimers, the Lyman people concluded, "The rule of thumb is that high speed, high pressure cartridges shed more speed in short barrels than do the low speed, large bore types." It's funny, but that is what I had suspected all along!

mancius1
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# Gesendet: 4 Mai 2011 10:41 - Edited by: mancius1


PAKO, skaičiau visą šitą reikalą, gaunasi, kaip ir ada.ru rašo, kad turėtų būt apie 20m/s 20 colių vamzdžiui palyginus su 24 colių (cal. .308 win), bet pagal kulkos kritimą kažkodėl atrodo, kad mažėja daugiau greitis.
reiks ieškot kolegų, kas gali realiai pamatuot

PAKO


# Gesendet: 4 Mai 2011 11:36


mancius1
O pagal ka matai, kad krenta daugiau ? Jei orentuojiesi i greiti parasyta ant soviniu dezutes ir minusuoji netekima nuo jo tai manau, kad nebus tikslu, nes tai ka deklaruoja gamintojas nevisada atitinka. Reiketu zinoti faktini pradini greiti ir tuomet atmetineti tuos ~23m/s
Aisku geriausia tai vienodais soviniais susauti is skirtingo ilgio vamzdziu ir butu aiskiau viskas ;)
Rask 60cm varmintine tikka 308 ir suderinsiu su turinciu 51cm vamzdi ;)
Tik chronografo neturiu kur paprasyt, nors labai ir neieskojau, gal ir atsirastu pas kazka ;)

mancius1
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# Gesendet: 4 Mai 2011 12:14


Spėju, kad krenta daugiau, nes:
Tarkim pradinis gamintojo greitis 765m/s 600mm vamzdžiui, balistinis koef 0,48.
Prišaudyta ant 100m prie +10, kritimas ant 200m 3,3-3,4MOA, ant 300m 7,5-7,6MOA prie +21C.
kad gaut tokius parametrus turiu suvest į balistinį kalkuliatorių greitį 690-700m/s.
Muškieta T3 TAC 308 51cm.

PAKO


# Gesendet: 4 Mai 2011 19:56


mancius1
kaip ir sakiau, gamintojas prideklaravo aukstesni greiti, trumpas vamzdis dar biskiuka ateme ir gaunasi taip, zodziu reikia antros tikkos varminto bei chronografo ir zinosi konkreciai be formuliu, skaiciavimo ir speliojimo ;)

mancius1
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# Gesendet: 5 Mai 2011 08:41


Tai panašu, kad reikės ieškot kas turi Bet kokiu atveju ačiū už patarimus.

Medziotojas 25
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# Gesendet: 30 Mar 2013 22:38


mancius1
Ar teko atlikt testa 51cm.60cm. vamzdziu kiek skiriasi kulku greiciai ir kulkos kritimas?

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