Powder questions in a rifle

Discussion in 'Ammunition & Reloading' started by dustinoif3, Oct 20, 2012.

  1. dustinoif3

    dustinoif3 New Member

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    Okay guys. I've been pondering this for awhile. At what length of barrel and twist rate do you decide on a fast or slow burning powder? I've read that you want a slow burning powder in a longer barrel rifle so you can maintain higher pressure longer till the bullet leaves the barrel. Faster powder for pistols and shorter barrels. So what's the deciding factor on length? I'm shooting a 20" bull barrel in my 700. Would a 20 need a faster burning or middle of the road? someone recomended h380 but he mentioned its a faster birmig middle of the road?
     
  2. nitestalker

    nitestalker New Member

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    No answer, you did not say what caliber you are loading for. What bullet do you intend to use ?:confused:
     

  3. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    To me caliber is the deciding factor. Short case like the .308 or .223, I use faster powders (like W-748 and BlC-2). Large case like the belted magnums and .25-06 I use slower powders (like H4831 SC). REALLY Large capacity cases (.338 RUM)scream out for Retumbo.
     
  4. nitestalker

    nitestalker New Member

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    Yep, agreed all good tips. We have to know if he is loading a badly overbore capicity round as well.;)
     
  5. Axxe55

    Axxe55 The Apocalypse Is Coming.....

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    some powders due to their composition are very versatile and will work in a multitude of calibers. faster and slower powders can even be used in the same caliber depending on bullet weight. best source is a good load data book. just look up whatever caliber you want to load for and choose the appropriate powder for the bullet weight you want to shoot. they will list all the available powders that can be used. also look up the powder makers data online.
     
  6. steve4102

    steve4102 New Member

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    If we are talking rifles, I do not care about twist or barrel length. The powder is burned up in the first few inches and barrel length has nothing to do with complete combustion.

    I load my rifles with a powder that gives at least 90% case fill, but I prefer compressed and more like 110% fill.

    Again, barrel length has nothing to do with burn rates, velocity yes, burn rates and complete combustion, no.
     
  7. Intheshop

    Intheshop New Member

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    Get a cpl new reloading books.

    Also be aware that powder co's have free guides as well.Usta have them in gunstores,prolly need to call/write for them now?

    Buy used loading books for penny's on the dollar.Not completely up to date but have tons of good solid info.

    Online sources.

    Find somebody who's loading/shooting similar equip....and disciplines.


    What above should do is keep steering you in a positive direction.You'll start to notice some overlap or consistency's in not only powder's burning rate but,manufacturers as well.Also should see similar bullets that keep popping up.Theres probably a reason for it.Don't reinvent the wheel.

    What calibre are you loading...308?Factory brrl?Have you measured the chamber/leade?
     
  8. dustinoif3

    dustinoif3 New Member

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    Sorry I meant to put the rifle but forgot. I'm shooting a Remi 700 .308 sps tactical. Barrel is 20" with a 1:12 twist. Currently shooting black hills 168gr bthp. I would like to try some 175's. I've had multiple people mention 175gr was prolly the heaviest I wanna go due to barrel length and twist. I have yet to measure the chamber. Currently my reloading stuff is in a box because I'm moving in a week or so. I purchased a set of dies the other day so I'm finally closer to making .308 win. I wanted to get some feedback before I went and bought powder so I'm not wasting money.
     
  9. dustinoif3

    dustinoif3 New Member

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    I haven't picked a bullet style yet and I haven't taken my calipers into the store to check lengths. The closest I've got was a google search that shot me to a forum which showed lengths from many makers. I applied the green hill formula to some measurements a guy gave for some Sierra mk and came up with a 1:11 twist for 175gr bullet.
     
  10. Axxe55

    Axxe55 The Apocalypse Is Coming.....

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    Steve i beg to differ. when you get that huge muzzle flash out of the barrel when shooting shorter barreled firearms, that combustion.

    my 25-06 when shooting a reload with a 120 gr bullet has little muzzle blast. when i shoot a hot reload with 75 gr bullets it has a huge muzzle blast that can be seen in the scope.

    this was alos a problem with the 220 in earlier years, and caused them to have a reputation as barrel burners, because they didn't complete the combustion in the cartridge, but did in the barrel.
     
  11. nitestalker

    nitestalker New Member

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    Axx there needs to be an adult on this forum from time to time. Thanks for the post.:)
     
  12. Axxe55

    Axxe55 The Apocalypse Is Coming.....

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    first of all what type of accuracy are you getting with the 168 gr Black Hills ammo? what ranges are you wanting to shoot at? hunting rifle or target rifle? why wanting to move up to 175 gr bullets?

    another thing to consider is that the twist ratio determines the accuracy of the weight of bullets you intend to use. off the shelf rifles use a twist that allow decent accuracy with a broad range of bullet weights. custom barrel makers can make a barrel in a different twist ratio tuned specifically for a narrow range of bullet weights that can be very accurate. so a factory rifle barrel will be more accurate with some bullet weights over others. this is why if you only shoot factory ammo, you try out different brands and weights of bullets to find out what works the best. reloading allows you to fine tune to your specific rifle. so unless you plan on changing the barrel from the 1-12 to a 1-11 twist, you need to work with what that barrel likes and it may or may not like bullets that weigh 175 gr.
     
  13. dustinoif3

    dustinoif3 New Member

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    The rifle shoots the black hills great. Will shoot 1/2 moa at 100 on one of my good days. At 200 it will around 1.75. Haven't seen it on paper at 300. Took a course awhile back and we shot from 300 to 800 in 100y increments on 12x18 steel. When I first bought the rifle I fed it gmm and it shot very well. Just got tired of paying for it. It was also a 168gr bthp. Right now the rifle just punches paper. I thought maybe at some point I'd kill something with it so that's why I was going to see what the max weight would be. Obviously it likes the 168 so I should prolly stick with that. When I start loading I'd like it to be a ballistic tip of some brand. The big reason why I'd like to hand load for it is that if I can make a round that would out shoot the big brands I'd feel like I really did something awesome on the bench. I wanna max the potential of this rifle.
     
  14. Axxe55

    Axxe55 The Apocalypse Is Coming.....

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    stick with the 168 gr bullets as they seem to be doing just fine and even will work fine for hunting if you use the correct type of hunting bullets. just find the load data for the 308 and start working up some loads for the 168 gr bullets. personally i use IMR 4350 powder for my 308 and have had good results.
     
  15. Intheshop

    Intheshop New Member

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    JMO,and it may seem obvious but.........

    Once a rifle/shooter starts getting under MOA things get interesting....duh.But what I've noticed is folks aren't spending enough time and effort on their shooting accessories.IOWs....as your accuracy "requirements" go up the scale,so should your shooting equip and technique.

    If I had a .308 in factory trim shootin 1/2" groups,consistantly off of "make-do" rests.....would work on my technique and upgrade the rest system BEFORE making changes to fire system.Then windflags,then chrono,then scope upgrade.

    "Then" I'd start foolin with loads.Otherwise you're either chasin bullet holes or having inconsistant results.Shooting one group in say the 2's or 3's out of ten or so groups is not consistant.
     
  16. dustinoif3

    dustinoif3 New Member

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    I'm confident in my equipment and shooting technique. I'm ready to make a round that is perfect for that rifle.

    The battleship target was at 100. Pitted my rifle against a 22-250 one day.

    Future plans are to change the stock to a competitive edge gun works stock
     

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  17. 1hole

    1hole New Member

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    "I've read that you want a slow burning powder in a longer barrel rifle so you can maintain higher pressure longer till the bullet leaves the barrel. Faster powder for pistols and shorter barrels. So what's the deciding factor on length?"

    Pick your most effective powder from a loading manual by bullet weight, not from a powder burn rate chart. Regardless of bullet weight, whatever powder will give you the highest speed in a 26" barrel will also be fastest in a 16" barrrel.

    Muzzle blast is a wholly different question. If you want to decrease muzzle blast use a reduced charge of a faster powder to lower the bore pressure at bullet exit.
     
  18. dustinoif3

    dustinoif3 New Member

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    I've had some really good feedback on this post. I thank everyone that's shared there piece
     
  19. steve4102

    steve4102 New Member

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    Sorry, no. The powder burns completely in the chamber and a few inches into the barrel. The gasses created by the burn travel down the bore generating bullet velocity. Some of these gasses will ignite when reintroduced into an Oxygen rich environment as they exit the barrel. The powder has burned and done it's job, the gasses created by the powder burn are what cause the flash.
     
  20. 1hole

    1hole New Member

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    "The powder burns completely in the chamber and a few inches into the barrel."

    Not quite. Peak chamber pressure occurs within a very few inches of bullet travel but few charges are completely burned before bullet exit even in long barrels.

    From ignition to bullet exit typically runs around 3-5 thousants of a second so the burn couldn't possibly be started and completed and the fire go out in such a brief time. With powder burn continueing the whole time there's no need for a secondary ignition when freed into the air and muzzle blast is determined by the remaining pressure at bullet release. Once the burning gases are released, most unburned powder kernels will extinguish; it's easy to find them in snow.