Ballistics and mainstream production

[BigBear]

Hello Folks,
I am not a reloader. However, I have a friend that is. Recently, we took my .308 out and shot a few hours a mix of reloaded ammo and off the shelf product from 100 to 600 yards. I did notice an increase in accuracy in minute amounts over my off the shelf ammo among the reloaded ammunition. So a question begs me to ask:

For the .308, what is the most reliable (read consistently accurate) off the shelf ammunition that you may have found? I am not sure if penetration/power needs to be taken into account as I'm a paper shooter. Let's aim for a hunting load though.

With all the different grains, weights, bullets, etc, is there a decent resource to look at to explain all the differences if I may want to take up reloading at a later point?

If you use acronyms, please explain them. Thanks.

Another variable question: Why is some ammo (same grain/power) more expensive than others off the shelf (Federal American Eagle 124 gr 9mm vs. Winchester 124 gr. 9mm)? Does this translate into better performance or just that the Winchester is cleaner so the firearm doesn't foul up as quick?

[SA Friday]

What make and manufacturer or 308? What's the length and rifling twist of the barrel? These are the big things we need to better help you.

I am a firm believer that reloads will always be more accurate over factory in a rifle. There are things you can do with a reload that the factory will never be able to do. For example, after you fire rounds from the rifle, you can choose to full length resize or neck resize the case or resize somwhere in between. Leaving the brass fire formed to the chamber diameter of the actual gun it's going to be fired out of can tighten up groups. Additionally, if the gun allows for it, you can seat bullets into the case longer to get the bullet to the best length for the gun. Combining these two techniques with really good brass preperation, and factory will never be able to get this good a result.

Factory ammo is made to fit and fire in any chamber of the same caliber. They cannot take advantage of preparing and loading the round for one specific gun. I have seen some very good factory ammo, and there are many reports that the Federal Match .308 ammo with the 168gr bullet is some of the most accurate factory ammo made.

Ultimately, IMO if you are not reloading you will never see the best your rifle can shoot. For rifle reloading and learning with, you really cant beat an RCBS Rock Chucker starters kit or similar kits by Lee or Hornady.

I have never gotten acceptable results from factory ammo. Acceptable to me is 1" groups or less at 100 yds. Every one, even my cheap rifles, can do this with reloads. I've even gotten groups as small as .5" from hunting rounds reloading.

The best reloading reference I've read is the Lyman reloading manual. The beginning chapters are well written to explain the info you need IMO. It's what I started with and re-read the beginning chapters over and over when learning. The BEST thing to do is find someone that can teach you how to reload. NRA has instructors, and there are more than a few on this forum that could teach you.

Ammo price differences are for multiple reasons. Some is the difference in the materials used to make the ammo, higher quality bullet for a defensive round vs a fumm metal jacketed target round. Other differences is cost in manufacturer. It costs smaller manufacturers more than it costs the larger manufacturers to make the exact same ammo. I wouldn't worry about fouling too much from factory ammo. All in all, factory ammo is pretty clean shooting.

OK, I think I answered all the questions. Post if there are more.

[BigBear]

SA Friday... Thank you Sir. Very informative. I'll google the book referenced.

More questions, as per your answers.

If a round is made for a specific gun, can it still be used in other firearms? i.e. if I reload for a particular .308, can I still use that round safely (if the head space is cleared, etc) in a different make/model .308?

Why does length and rifling twist play a role if the grain/powder is enough to throw out of barell? For reference, mine is an above average, very nice HOWA 1500, 24' barell (threaded for can if that makes a difference) with a twist rate of 1:12. I can put 10 shots at an inch for 100 yrds with this "stock" rifle, just am curious if it can get better with reloads...


Last question for now... Do you find that reloading is cheaper than just stocking off the shelf ammo? (350 for press, X amount for dies/punches, x amount for other gear, then grain, bullets, etc.. seems like it could get expensive quick.) Let's settle for about 1K a month each caliber (5 total) rounds fired.

[Irving]

You can have a barrel twist that is too slow to stabilize a heavier grain bullet and start getting key holing and tumbling.

[BigBear]

You can have a barrel twist that is too slow to stabilize a heavier grain bullet and start getting key holing and tumbling.

Yes Sir, I thought about that as soon as I hit the "submit" button. Another thing I just thought of are the Boattail projectiles and jacketed and blah blah blah. A lot of information. Guess I'll be busy reading for the next few years, lol.

[SA Friday]

SA Friday... Thank you Sir. Very informative. I'll google the book referenced.

More questions, as per your answers.

If a round is made for a specific gun, can it still be used in other firearms? i.e. if I reload for a particular .308, can I still use that round safely (if the head space is cleared, etc) in a different make/model .308?

Why does length and rifling twist play a role if the grain/powder is enough to throw out of barell? For reference, mine is an above average, very nice HOWA 1500, 24' barell (threaded for can if that makes a difference) with a twist rate of 1:12. I can put 10 shots at an inch for 100 yrds with this "stock" rifle, just am curious if it can get better with reloads...


Last question for now... Do you find that reloading is cheaper than just stocking off the shelf ammo? (350 for press, X amount for dies/punches, x amount for other gear, then grain, bullets, etc.. seems like it could get expensive quick.) Let's settle for about 1K a month each caliber (5 total) rounds fired.

As Sturtle said, the rifling twist comes into play with the different bullet weights. Essentially, you need a faster twist to stabilize heavier/longer bullets. A 1 in 12 twist in a 308 is pretty much standard. You will probably be able to shoot up to 180gr bullets out of it fairly well. Heavier bullets might be a problem. I would stick to the 165 to 168gr bullet area for the best results. The Howa 1500 is a pretty good rifle. The 24" barrel might be a touch too long for the 308 cartridge, but won't hurt anything. You can get a barrel too long for the powder used and the powder burns out before the bullet leaves the end of the barrel. It doesn't hurt anything but you can lose a small amount of velocity. Slower burning powders can sometimes help with this, but if you get an accurate round, don't worry about this...

If a round is made for a specific gun, it can in theory still be used in a different firearm as long as your headspace is still safe, the round chambers, and the chamber pressures are within limits. If you are looking at using reloaded ammo in two different guns, I would recommend fully resizing or a loose full resize till the round chambers in both guns, and then testing both chambers for optimum bullet seating depth of the shortest headspace. Then test in both guns. Option two is reload for both guns differently customizing the different reload for both guns individually. Trust me on this, after reloading for a while you will find making factory spec reloads as boring as kissing your sister.

You do save money reloading. With that said, it really depends on the amount you reload/shoot as to when the reloading starts paying for itself. For example, an average USPSA pistol competition shooter (20k to 30k rounds in a year) can essentially pay off their Dillon 550b reloader and accessories from the savings in ammo cost in 6 months. Someone who shoots maybe a 1000 rounds a year may have to reload for a couple of years before they see it pay for itself. Reloading, from a financial perspective, is an investiment into future savings. The savings is dependent on the shooters ammo consumption.

The other benefits to reloading is making your ammo with the exact components you want to suit the gun and use. Another pistol example; Winchester White Box (WWB) target ammo (115gr FMJ bullet) for 9mm is about $15 per 100 rounds. Out of a Glock 34, I get 138 power factor (pf) with this ammo. I can reload 9mm ammo with a 147gr bullet at a lower pf (130 pf) for about $10 to $12 per 100 rounds. My reloads are softer shooting, knock down steel targets better, and more accurate. This equals more points and faster times when shooting competitively. There's a slight financial benefit, but the resulting ammo benefits are worth much more than the money in this case.

When it comes to high quality rifle ammo, the savings is much higher per round. Reloading 168gr match grade ammo compared to buying it is a huge savings. I don't have exact numbers, but I would suspect it's at least half the price. I know I save an ass load (technical term) of money reloading for my 300 Win Mag for high end hunting ammo, and it's more accurate than any factory ammo I've tried. It's hard to compare prices directly since I use the components that I want, and doesn't necessarily correlate to the ammo that is offered by manufacturers.

[BigBear]

Essentially, you need a faster twist to stabilize heavier/longer bullets. You will probably be able to shoot up to 180gr bullets out of it fairly well. Heavier bullets might be a problem. The 24" barrel might be a touch too long for the 308 cartridge, but won't hurt anything. You can get a barrel too long for the powder used and the powder burns out before the bullet leaves the end of the barrel. It doesn't hurt anything but you can lose a small amount of velocity. Slower burning powders can sometimes help with this, but if you get an accurate round, don't worry about this...

Wow... very good information presented in an easy to understand manner. If I ever meet you, I'll buy dinner. A few more questions and then I'll leave the matter to books I can find.

I edited a few sentences out of your first paragraph to help organize my thoughts and ask accordingly...

I do understand that a fast twist rate will help in stabilizing the bullet. Please clarify the "heavier bullets might be a problem" statement. Just the bullet or the whole cartridge? Isn't the powder in the cartridge loaded to ensure the bullet will exit the barell with the appropiate velocity? I think that questions goes in conjunction with me asking why the 24 inch barell might be a touch too long. If there is enough powder, couldn't I use a 28 inch barell? I'm trying to figure out what role barell length plays. It is answered in the last sentence but a slow burning powder doesn't make sense to me... don't you want the powder to burn quickly and efficently to raise as much velocity upon striking as possible to literally throw the bullet out of the rifling which in turns helps spin the bullet to keep as flat a trajectory as possible?...

Thanks.

[SA Friday]

The one in-depth study I read about barrel length in comparison to burn rate essentially found any barrel over 28" in a standard caliber is too long to accomidate the powder burn. Powder burns the entire time the bullets travels to exiting the barrel. If the powder runs out before the bullet leaves the barrel, you no longer have push behind the bullet and the bullet slows down from friction. Theoretically, maximum velocity is reached from a consistant powder burn to the exact end of the barrel. Depending on case capacity, you can have a barrel too long to accomidate a short case with fast burning powders. Slower burning powders burn longer and release more gas at a slower rate. This is why shooters with guns that have comps on the end of the barrel use slower burning powders. They get more gas from the powder and push it out of the comp to get the reverse pressure to neutralize some of the recoil.

Velocity comes into play if you are pushing a bullet way out there.
The bullet transversing from sonic to sub-sonic casuses an instability. So, you really can't shoot accurately past this tranversing of the sound barrier, depending on weather conditions is somewhere in the neighborhood of 1020fps. You want to push a 168gr 308 round out to 1000 yds, you have to maintain sonic velocity out to that distance. The longer barrel is an advantage as long as you are getting a burn to the end of the barrel. If you are not, you are losing some velocity.

From what I researched about 308 target rifles, they pretty much stick to 20" or 22" barrels to optimize the case capacity burn ratio. Is two inches going to make a difference? Maybe, but not much. If you are not pushing rounds out that far, it's really irrelevent.

[Mista Bukit]

[quote=SA Friday;146192]As Sturtle said,

You do save money reloading. With that said, it really depends on the amount you reload/shoot as to when the reloading starts paying for itself. For example, an average USPSA pistol competition shooter (20k to 30k rounds in a year) can essentially pay off their Dillon 550b reloader and accessories from the savings in ammo cost in 6 months. Someone who shoots maybe a 1000 rounds a year may have to reload for a couple of years before they see it pay for itself. Reloading, from a financial perspective, is an investiment into future savings. The savings is dependent on the shooters ammo consumption.


When you are talking about an investment, don't forget the return on your equipment if you sell it. For instance, I just bought a Ruger LCP in .380. So now to load this new caliber and since I have a Dillon 550, it costed me around $90 for the dies and the conversion kit. $90 buys about 100 rounds of training ammo and components to reload cost between $.15 - $.20 a round. Since I can sell the dies and conversion kit on E-Bay for most of what I paid for them the only real cost is for the components.

[BigBear]

Hmm.. I may need to look into this more thouroughly. Another thought crept into my mind this morning.

Earlier, we said that 24inches is a bit long for a .308 barell. I plan on putting a can so that will add another 5-7 inches. Would it be prudent to chop the barell, rethread, recrown, etc down to something like 18 inch or so? If so, will that have an effect on the rifle when ran without the can? Lots of thoughts..