Most of the data im reading in .308 150g. It seems to be common to use either IMR4064, Varget. All of the books I have are useing a 22"-24" barrel. Now for the question. If you use an 18" barrel should you use a faster burning power? And please support your answer on this. My thinking yes so I dont have to deal with a lot of muzzel flash and wasted powder thats not helping me any. So i thought of useing IMR 4895 or IMR 8208. Any other powder possiably needs to be for a service gas tube gun.
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Faster burn rate with a shorter barrel would allow the powder to burn more completely before the projectile exists the muzzle....which I've also heard is a myth (and I tend to agree)...so, do your own research.
This a good chart for reference....remember to only use powder recommended for your caliber though.
This a good chart for reference....remember to only use powder recommended for your caliber though.
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Years ago the maker of a line of lightweight "mountain" rifles did some testing of various powders to determine what to use for the 18" barrels he was supplying in .270 Win. He found, to his amazement, the standard slow burners gave better velocity and accuracy than faster powders. FWIW
The Sierra manual has .308 "rifle" data and "single shot" .308 pistol data. And by looking at the reloading manual you will see the loss in velocity with the shorter pistol barrels and can make better powder choices.
NOTE: W748 is used in the M14 rifle.
Firearm used Savage 12VSS 26 inch barrel
Rifle, 150 grain bullets, max load W748 47.9 grains, 2900 fps
Firearm used, Pachmayr Dominator, 14 1/8 barrel
Single Shot Pistol,150 grain bullets, max load 49.0 grains, 2600 fps
Hunting load, W748, 47.1, 2500 fps
Accuracy load, W748, 47.1 2500 fps
I have a 30-30 Winchester Trapper Model with a 16 1/2 inch barrel, one day I was looking through the pistol data and discovered that W748 powder worked well in 20 inch barrels and 14 inch Contender pistol barrels. Just remember to use magnum primers to speed things up! (but there is more muzzle blast with the shorter barrel)
As a side note one day I was just getting on the walkway of our pistol range and a person was getting ready to shoot a Contender pistol. When the Contender went off the pistol spit fire and flame several feet, it just about pointed straight up and almost rotated 90 degrees. It was a 35 Remington shooting 200 grain factory ammunition, seeing the blast, recoil and torque that day I lost all interest in getting a Contender pistol. Load density is one thing and setting the woods on fire and dislocating your shoulder is another.
Quickload likes RL-17, IMR-3031, IMR-4895, W748, BLC2 in that order.
NOTE: W748 is used in the M14 rifle.
Firearm used Savage 12VSS 26 inch barrel
Rifle, 150 grain bullets, max load W748 47.9 grains, 2900 fps
Firearm used, Pachmayr Dominator, 14 1/8 barrel
Single Shot Pistol,150 grain bullets, max load 49.0 grains, 2600 fps
Hunting load, W748, 47.1, 2500 fps
Accuracy load, W748, 47.1 2500 fps
I have a 30-30 Winchester Trapper Model with a 16 1/2 inch barrel, one day I was looking through the pistol data and discovered that W748 powder worked well in 20 inch barrels and 14 inch Contender pistol barrels. Just remember to use magnum primers to speed things up! (but there is more muzzle blast with the shorter barrel)
As a side note one day I was just getting on the walkway of our pistol range and a person was getting ready to shoot a Contender pistol. When the Contender went off the pistol spit fire and flame several feet, it just about pointed straight up and almost rotated 90 degrees. It was a 35 Remington shooting 200 grain factory ammunition, seeing the blast, recoil and torque that day I lost all interest in getting a Contender pistol. Load density is one thing and setting the woods on fire and dislocating your shoulder is another.
Quickload likes RL-17, IMR-3031, IMR-4895, W748, BLC2 in that order.
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I shoot a .308 18" bolt gun, I have only tried varget but am looking forward to 8208XB
Cartridge design and efficiency obviously has a effect on the velocity vs. barrel length vs. burn rate argument. The .308 is forgiving and efficient making much of the argument probably mute. With a 150 grain slug it shouldn't be hard to get decent velocity
I used to load 150 grain Nosler BT's over IMR 4064 for a friend with a 20" bolt gun (hunting) with very good results.
Cartridge design and efficiency obviously has a effect on the velocity vs. barrel length vs. burn rate argument. The .308 is forgiving and efficient making much of the argument probably mute. With a 150 grain slug it shouldn't be hard to get decent velocity
I used to load 150 grain Nosler BT's over IMR 4064 for a friend with a 20" bolt gun (hunting) with very good results.
It's actually an urban legend that it takes your full barrel to burn out a powder charge. Actually, virtually all the powder is burned out within just the first few inches. Just keep in mind that pressure is still applied to the bullet, even after all the powder is burned out. This continued pressure adds velocity, and will do so, so long as there's pressure.
It's the generally the charge weight that determines how much velocity you can impart to the bullet, but must do so within the bounds of acceptable pressure. Ergo, "burn rate".
Therefore, you really gain nothing by a faster burn rate, so long as the "original" powder you WERE shooting was properly matched to the requirements of your chamber/bore/bullet.
It's the generally the charge weight that determines how much velocity you can impart to the bullet, but must do so within the bounds of acceptable pressure. Ergo, "burn rate".
Therefore, you really gain nothing by a faster burn rate, so long as the "original" powder you WERE shooting was properly matched to the requirements of your chamber/bore/bullet.
Apparently you know much more about this than I do. Please explain to me how an extra 9% of powder burns between the difference of 18" and 32" barrels in a 30.06 using Reloader 50???? 81.24% in 18" versus 90.64% in 32". I think that your blanket statement, while it has some merit, is not necessarily accurate. I know you will jump on me and ask why I would use Reloader 50 in a 30.06, and I am not. I just ran the numbers to prove a point.
OP---If you have access to QL, try to choose a powder that is usable in the cartridge you are trying to load, look for higher than 99% burn, or as close as you can get to it, and go from there. Faster Powders often create higher peak pressures, so keep this in mind, and be careful in your load work-ups to start low and watch for pressure signs.
As a rule of thumb, longer barrels allow you to use slower powders, and conversely, you want to use faster powders in a shorter barrel. You can also ask the powder manufacturer if a powder can be used in a rifle it is not listed for, sometimes they can be with good effect.
Give Alliants Power Pro 2000 MR a try. It's a double based ball powder but has some flattened flakes. It's relatively fast both in burn rate and velocity. In theory ball powders are more temp sensitive but I have not found this to be the case with Power Pro. At least not from 25 to 95 degrees. I use it for heavy bullets in .308, 223 and 22-250. I have 18" and 26" Savage rifles. 48g under A 178 Amax in Lapua brass gave me 2754 in the 26 and 2680 opinion the 18 with very low ES's. Even better I'm shooting the big Hornady 80g Amax out of my 26" 22-250 at 3230 FPS! Was hitting steel plates at over 1000 with only 27 MOA elevation...a full 7 MOA less than my .308. Killer powder, meters like water and for me easily available locally. Done with the Varget and RE15 quest.
" If you use an 18" barrel should you use a faster burning power?"
No, contrary to 'conventional wisdom' BS to the contrary. And complete combustion isn't a valid concern, 'efficency' of the burn is irrelivant. Who cares if some of the powder never ignites, we're only concerned with what occurs with the powder that does burn!?
Sporting cartridge chamber pressures typically peak at 3-4 inches of bullet travel but velocity continues to increase because there's still a lot of pressure pushing down the bore. Bullet velocity is dependent on the total area under the pressure:bore time curve. In English, that means what ever powder and charge that produces the highest speeds in a long barrel will do the same if you cut that barrel back. In a shorter barrel you will certainly lose speed and gain muzzle blast but it's due to the reduced time under pressure and swapping powder won't get it back.
No, contrary to 'conventional wisdom' BS to the contrary. And complete combustion isn't a valid concern, 'efficency' of the burn is irrelivant. Who cares if some of the powder never ignites, we're only concerned with what occurs with the powder that does burn!?
Sporting cartridge chamber pressures typically peak at 3-4 inches of bullet travel but velocity continues to increase because there's still a lot of pressure pushing down the bore. Bullet velocity is dependent on the total area under the pressure:bore time curve. In English, that means what ever powder and charge that produces the highest speeds in a long barrel will do the same if you cut that barrel back. In a shorter barrel you will certainly lose speed and gain muzzle blast but it's due to the reduced time under pressure and swapping powder won't get it back.
Fuzzball, I have to question you on your saying that complete combustion is not an issue. What do you base this statement on?
From what I have read, and it seems to be validated by my limited testing, The closer you get to complete burn, the lower the extreme spread on velocities. If you are not burning all the powder, then one shot may burn more than another, and cause larger differences in velocity from shot to shot. When I have taken this into account in choosing powders, I have noticed tighter groups and smaller velocity differences. This may be coincidental, but from what I read, it is true to form.
Furthermore, the laws of physics dictate that if there is more powder burnt in a longer barrel, then the "push" from the extra burnt powder will translate into more velocity in addition to the harnessing of the pressure for a longer time. I therefore have a hard time in believing your flat statement. It is possible that the difference, though real, is not really measurable given the fact that we are talking in my case 1.734 milli-seconds.
Can you shed more light on this, please?
From what I have read, and it seems to be validated by my limited testing, The closer you get to complete burn, the lower the extreme spread on velocities. If you are not burning all the powder, then one shot may burn more than another, and cause larger differences in velocity from shot to shot. When I have taken this into account in choosing powders, I have noticed tighter groups and smaller velocity differences. This may be coincidental, but from what I read, it is true to form.
Furthermore, the laws of physics dictate that if there is more powder burnt in a longer barrel, then the "push" from the extra burnt powder will translate into more velocity in addition to the harnessing of the pressure for a longer time. I therefore have a hard time in believing your flat statement. It is possible that the difference, though real, is not really measurable given the fact that we are talking in my case 1.734 milli-seconds.
Can you shed more light on this, please?
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SU- No problem, I hear what you're asking... but I do wish to restate my caveat, as in the above post: "...Therefore, you really gain nothing by a faster burn rate, so long as the "original" powder you WERE shooting was properly matched to the requirements of your chamber/bore/bullet."
In other words, if your powder is TOO SLOW for your cartridge/bullet/primer/bore, then you WILL see an affect, given different barrel lengths.
I realize this can be confusing.
Bottom line is that there is no benefit in using a faster powder, given a shorter barrel. If your powder choice is reasonably appropriate, then it'll all be burned out in a fairly short time.
In other words, if your powder is TOO SLOW for your cartridge/bullet/primer/bore, then you WILL see an affect, given different barrel lengths.
I realize this can be confusing.
Bottom line is that there is no benefit in using a faster powder, given a shorter barrel. If your powder choice is reasonably appropriate, then it'll all be burned out in a fairly short time.
Thanks. I think I get what you are saying.
My point was that I have not come across a reference book that has all the possible powders listed for all the possible cartridges that it may work in.
Thus, I work off Quick-Load, and try to have 80%>Fill Capacity<110% (over 80, less than 110) and more than 98% propellent burned. By doing this, I can tailor my powders to my rifle, according to what I can get and what I can get performance from. Obviously, I follow proper loading procedure---Start Low, work up watching for pressure signs.
I am using Reloader 50 with good success in a 338LM----34" barrel, 109.5% fill capacity, 99.4% propellant burned, 2800+FPS at my OBT node. This is the highest velocity yield given the node I am trying to attain. While a faster powder may burn completely, it is creating much higher chamber pressures, and not getting me into my node with nearly the same velocity. Thus, the choice to use a powder which is not typically used in this application. That is where I am coming from in my statement.
My point was that I have not come across a reference book that has all the possible powders listed for all the possible cartridges that it may work in.
Thus, I work off Quick-Load, and try to have 80%>Fill Capacity<110% (over 80, less than 110) and more than 98% propellent burned. By doing this, I can tailor my powders to my rifle, according to what I can get and what I can get performance from. Obviously, I follow proper loading procedure---Start Low, work up watching for pressure signs.
I am using Reloader 50 with good success in a 338LM----34" barrel, 109.5% fill capacity, 99.4% propellant burned, 2800+FPS at my OBT node. This is the highest velocity yield given the node I am trying to attain. While a faster powder may burn completely, it is creating much higher chamber pressures, and not getting me into my node with nearly the same velocity. Thus, the choice to use a powder which is not typically used in this application. That is where I am coming from in my statement.
Actually, given the expansion ratio of the 338 Lap Mag, compared to the .50 BMG, and that you're likely shooting a 250 or 300 grain bullet, your powder choice seems reasonably appropriate. US 869 is a .50 BMG propellant, but works quite well in both the .338 Lapua and .338 Norma, according to published reloading data, as well as my personal experience.
To your all powder/all combinations statement: You're right. It doesn't exist. But, there are two main impediments to the idea. First: Unintended consequences. Some powders, despite them having the right burn rate for the cartridge, are bad actors when it comes to secondary effects. Example: While you COULD load some FAST pistol or shotshell powders in a .223, and launch a bullet...given the right circumstances, you COULD run into catastrophic trouble (BIB, for example). So, generally, this combination is not even published. But, some have been tested, and found to exhibit good-enough ignition.
Second, cost/value to the publisher. Need say no more.
Your QL program affords you to investigate "what if", and that's quite a noble thing, especially considering that this culture is much more into video games and watching MTV. If more folks had the "bug" to investigate "what if", we'd probably not be in the current mess.
Just please know that some powders, despite their burn rate or (exponent), might "look" good in a model, the computer can not anticipate every unsafe combination.
Have fun, take great care, and start low and work up slowly. The red-neck check: ratchet strap your gun to an old tire. Get 50 yards of fishing line, tie it to the trigger, and "have at it". This is actually the way I proof my chambers. Why not!????
To your all powder/all combinations statement: You're right. It doesn't exist. But, there are two main impediments to the idea. First: Unintended consequences. Some powders, despite them having the right burn rate for the cartridge, are bad actors when it comes to secondary effects. Example: While you COULD load some FAST pistol or shotshell powders in a .223, and launch a bullet...given the right circumstances, you COULD run into catastrophic trouble (BIB, for example). So, generally, this combination is not even published. But, some have been tested, and found to exhibit good-enough ignition.
Second, cost/value to the publisher. Need say no more.
Your QL program affords you to investigate "what if", and that's quite a noble thing, especially considering that this culture is much more into video games and watching MTV. If more folks had the "bug" to investigate "what if", we'd probably not be in the current mess.
Just please know that some powders, despite their burn rate or (exponent), might "look" good in a model, the computer can not anticipate every unsafe combination.
Have fun, take great care, and start low and work up slowly. The red-neck check: ratchet strap your gun to an old tire. Get 50 yards of fishing line, tie it to the trigger, and "have at it". This is actually the way I proof my chambers. Why not!????
That is fair enough, and point taken on the possibility of bad actors that might show in QL as possibilities. I am not going too far off the range in my testing, though. I wouldn't be trying anything too weird without some technical input from the powder manufacturer. I found them to be quite helpful in that regard.
Thanks for the comments.
Cheers,
Tim
The Right to Keep and Bear Arms Shall NOT be Infringed
Thanks for the comments.
Cheers,
Tim
The Right to Keep and Bear Arms Shall NOT be Infringed
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