muzzle fire

j3081j3081 Member Posts: 332 ✭✭✭
hey guys,,,reloaded 6 rounds of .257 roberts yesterday,,,went to the range,shot 1 and could see in my scope after firing a blast of FIRE shoot out of the barrel,all 3 rounds did the same thing,,, but not a bad group of 1.250,,,then shot the .243 win to let the .257 cool down a little,,,shot the next 3 loads about 20 minutes later and the same thing happened,blast of fire with 1.347 groups,,,not bad as this is my first load made for this rifle,,,the rifle,a ruger m77,20 inch barrel,,,the load is 43 grains of IMR 4831,win +p cases,federal 9and 1/2 primers,rem 120 grain bullet and set .015 off the lands.now what would cause the blast of fire seen in my scope after firing the round,,,is it unburnt powder or is this normal for the load indicated,,,i dropped the load off 1/2 grain for tomorrows shooting,,,i never seen fire in my scope,,,thank you,,,j3081,,,oh no sighns of a pressure problem


  • dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    20in bbl.-powder still burning. Another 4in. of bbl. would help. Your 1/2 gr. less load should help, and mabe tighten up the group. i seen the smae thing when I went from a Savage tactical with a 24in bbl. to a Remingtom PSS-LTR with a 20in. bbl. I went with a different powder, the PSS did'nt like the same one.
  • jtmarine0831jtmarine0831 Member Posts: 908 ✭✭✭✭
    edited November -1
    Definately sounds like too much powder! I was thumbin' through Nosler's manual and 43gr is above recommended max, but that is just for .257 Roberts and not the +P load. I would drop to about 38gr of IMR 4831 and work up from there. I would imagine that you might quite possibly find a tighter group with less unburned powder before you get close to 43gr again. Here is a link to Load data compiled by IMR for just about everything. For some loads you can even get specifics for loads with just IMR powders. Hope I could help a little! Let me know what you come up with anyway, always curious about the success of others.

    Good Luck and Good Shooting!


    PerryShooter has a good point! IMR4831 is the second to slowest IMR has to offer. Here is a link to a burn rate chart so you can compare for yourself.

  • perry shooterperry shooter Member Posts: 17,390
    edited November -1
    Hello 4831 is a VERY slow burning powder If it were me I would go with a faster burning powder for this short of a barrel EDIT EDIT [:0] Maybe I did a poor job of explaining why I suggested a faster burning powder. The reason I suggested a different powder is in many cases you can get higher velocity from large case capacity cartridges with slow burning powders is because the push on the base of the bullet last for a longer time. However this can work against you if you have a short barrel. When the bullet reaches the muzzle and all of the powder has not burned you will have muzzle flash . This is a sign that you are wasting powder and the muzzle velocity will be lower then normal. The Thomson Center pistols with interchangeable barrel in rifle calibers have used faster powders for years to get rid of muzzle flash but still get good velocity. [:p]
  • j3081j3081 Member Posts: 332 ✭✭✭
    edited November -1
    hi guys,,,since the remington bullet is a spitzer bullet i went off of the speer #13 which reads 45 grains max,,,also looked at noslers and it said 41 grains max,,,also looked at sierras manual and there was no listing for IMR4831,,,so i went by speers manual,knowing that noslers was lower but still went 2 grains off the max in speers,,,there were no sighns of a pressure spike even though i am close to the lands,,,is there a correct word for muzzle fire,,,is it the bullet i am trying to shoot out of the .257,,,can't find any data on remington,,,i thought i was starting low,,,however i don't mind the muzzle fire,it's just the first time this has happened,,,already reloaded 6 rounds at 42.5 grains before i posted this,,,i'll let you know how it does,,,thanks for all the replies,,,and don't be afraid to post again,,,many thanks,,,j3081
  • dtknowlesdtknowles Member Posts: 810 ✭✭✭✭
    edited November -1
    Most often called Muzzle Flash. Military rifles sometimes have a Flash Hider on the muzzle to help some. It might be cool to shoot those loads at night just to really appreciate the Flash.

    The reason you see fire is that the gasses are still incandesent when they leave the barrel. This is either because the powder is still burning or has just so recently finished burning that a lot of the powder gases have not had a chance to cool down below their incandesent temperature.

    You could try a different powder, I am not sure that a small decrease in power weight with the same powder will help much.

    Trying to turn a .257 Roberts into a 25-06 is not a good way to go but then again if you have a .243 Win what do you expect the .257 to do that the .243 can't or vice a versa.

    Don't get me wrong but in my book there is not enought diffence between them to worry about.

  • nononsensenononsense Member, Moderator Posts: 10,542 ******
    edited November -1

    Muzzle Flash

    by Tony DiGiulian
    Updated 12 September 2006

    When a gun fires, only about 30% of the chemical energy released from the propellant is converted into the useful kinetic energy of actually moving the projectile down the barrel. The remaining energy is primarily contained in the propellant gas-particle mixture that escapes from the muzzle of the gun in the few milliseconds before and after shot ejection. A significant portion of this remaining energy is dissipated in the bright "muzzle flash" seen when the gun fires.

    This flash consists of at least the following five components:

    1) Muzzle Glow
    2) Primary Flash
    3) Intermediate Flash
    4) Secondary Flash
    5) Sparks

    1) Muzzle Glow is usually a reddish white glow or tongue of flame at the muzzle that appears just prior to shot ejection and persists after shot ejection until the chamber pressure drops significantly. The initial glow is usually the result of hot, highly compressed gases (unburned propellants) leaking past the projectile driving band and is brightest in a worn gun. These gasses are hot enough to emit radiation in the visible light band. A "Cold Gun" with its lubricated barrel generally shows less muzzle glow than does a "Hot Gun" with its expanded barrel.

    2) Primary Flash occurs after the projectile has exited the muzzle and is caused by those propellant gases exiting the muzzle behind the projectile. These are hot enough to emit large amounts of visible radiation but cool rapidly as they expand away from the muzzle.

    3) Intermediate Flash consists of a reddish disc, slightly dished towards the gun, which appears about three inches (7.5 cm) from the muzzle of a small-caliber weapon and about 20-25 calibers from the muzzle for larger caliber weapons. Intermediate Flash occurs at the time of shot ejection and persists until the chamber pressure drops. It is brightest at the edge nearest the gun and gradually fades as the distance from the muzzle increases. This flash is due to a Mach shock wave created by the escaping gasses and projectile which, with its attendant pressure rise, causes the propellant gases to attain a temperature almost equal to the chamber temperature and so become self-luminescent.

    4) Secondary Flash appears beyond the zone of the intermediate flash and is a rather ragged vortex of yellowish white flame. This is a result of the ignition of the combustible mixture of propellant gases and atmospheric oxygen caused by the turbulent mixing occurring at the boundary of the gas jet as it leaves the muzzle. The ignition of this mixture would appear to be initiated by its exposure to the high temperature of the intermediate flash.

    5) Sparks are a common feature of the flash for small arms. These can arise from the ejection of incompletely burnt powder particles or by the ejection of white-hot acid or metallic particles. The former can be crystals of potassium salts if the powder is a "flashless" one while the latter can be the residual fragments of the metallic components of the cap composition or fragments of burning metal from the bullet jacket or driving bands.

    Of these five components, the intermediate and secondary flash are the greatest contributors to muzzle flash. Most of the radiated energy occurs during the secondary flash and this can be greatly reduced by attaching a flash reducing device to the gun muzzle. These are commonly known as "Flash Suppressors" and appear on many military-style small arms and automatic weapons. These attachments act by modifying the gas glow pattern such that there is no region or a greatly reduced region in which the inflammable mixture of air and muzzle gases is sufficiently hot enough to ignite. It should be realized that there are other kinds of Flash Suppressors which do not modify the gas flow patterns in this manner but instead work by directing part of the muzzle gasses away from the shooter. These kinds of Flash Suppressors and the simpler "Flash Hider" muzzle attachments are intended primarily to reduce or block the muzzle flash from the vision of the shooter in order to maintain his night vision, they do little to reduce the size of the flash itself.


    Five Kinds of Flash
    Image from "Combat Systems I: Sensors" by Dr. Robert Harney of the Naval Post Graduate School

    Back to the Naval Technical Board


  • SCorversSCorvers Member Posts: 2,063 ✭✭✭✭✭
    edited November -1
    I'd try some IMR 3031. Worked wonders on my 18.5" barrel 30-06. I'll go check may manuals for a 257 load.

    Edit: Lyman list 30-33 gr of 3031 behind a 117gr bullet. I'd start with 30.
    Modern Reloading suggest the same for the 120gr bullet. I wouldn't exceed 33 without being VERY careful. 3031 is a pretty fast powder and pressures can climb pretty high with just a minimum increase in charge.

    Good luck.
  • j3081j3081 Member Posts: 332 ✭✭✭
    edited November -1
    hi guys,,,after reading all of the replies from you good people,i've decided to pull the bullets and start over with 32 grains of IMR 4895 taken out of the sierra manual,5th edition where the max is listed at 35.8 grains,,,many thanks to all that have replied,and it don't get any better than the gunbroker forums and its members,,,great people,,,great ideas,,,and fantastic information,,,thanks all
  • fire for effectfire for effect Member Posts: 121 ✭✭✭
    edited November -1

    Flash? What Flash!!
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