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BigBear
12-07-2009, 11:32
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
12-07-2009, 13:40
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
12-07-2009, 13:51
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
12-07-2009, 14:11
You can have a barrel twist that is too slow to stabilize a heavier grain bullet and start getting key holing and tumbling.

BigBear
12-07-2009, 14:21
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
12-07-2009, 14:58
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
12-07-2009, 15:56
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
12-07-2009, 16:14
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.

SA Friday
12-07-2009, 16:22
Heavier bullets, in this case over 180gr, may not stabilize in the twist ratio you have in the barrel.

223 caliber is a great example of twist ratio vs bullet weight.
As a rule of thumb:
1 in 12 is good up to 55gr bullets, maybe 62gr bullet
1 in 9 is good up to a 68 or 69gr bullet, maybe a 77gr bullet
1 in 8 is good up to a 77gr bullet, probably a 80gr bullet too
1 in 7 is good up to a 90gr bullet

You have to test your gun with heavier bullets if you want to try them because every barrel is a little different, but overall, there is a pretty good understanding what twist rate will stabilize what bullet, especially for 223 and 308s. They get shot a lot.

BigBear
12-07-2009, 16:37
Very interesting. Thank you.

Mista Bukit
12-07-2009, 21:07
[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
12-08-2009, 13:43
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..

Irving
12-08-2009, 13:45
No, there is no friction inside the can. In fact, if I remember correctly, suppressors can help you gain a few fps, instead of losing it. I don't know any more detailed info though.

SA Friday
12-08-2009, 13:54
Some might recommend it, but it far from necessary. The bullet is not going to make contact with anything in the suppressor if everything works right. It's simply going to capture and control the release of the escaping gasses as the bullet leaves the barrel.

The biggest gain in cutting the barrel down would be manuverability of the firearm with the can on it. 4 inches of length can make a difference on just how easy it is to manuver around. Once again, as long as you are getting an accurate load through it, it's really not a big deal unless you plan on going through some training courses or competitions with it where being able to manuver it around would be beneficial.

BigBear
12-08-2009, 14:25
ok, I didn't ask correctly... Let me try to clarify. I understand there is no contact between bullet and suppresor. What I am asking is:

1. With a shorter barell, will I lose accuracy.
2. With can on and off, with a shorter barell will there be a more distinguished POI?
3. If the barell is long, made even longer with a can, then don't I run the risk of loads not exiting the barell?...

Thxs.

Irving
12-08-2009, 14:34
ok, I didn't ask correctly... Let me try to clarify. I understand there is no contact between bullet and suppresor. What I am asking is:

1. With a shorter barell, will I lose accuracy.
2. With can on and off, with a shorter barell will there be a more distinguished POI?
3. If the barell is long, made even longer with a can, then don't I run the risk of loads not exiting the barell?...

Thxs.

As for #3, no, because the contact with the bullet ends when the barrel ends. If the round will exit a barrel at all, then the presence of a can shouldn't change anything.

#2, the presence of a suppressor can change POI, but I'm under the impression that barrel length won't effect this in a significant way, since you will just adjust to whatever POI you end up with anyway.

#1, I don't think this has any relation to having a can or not.

BigBear
12-08-2009, 14:55
Correct Sturte, #1 has no bearing on use of a can. I am asking with a shorter barell at the given twist rate, will that reduce accuracy? Or does twist rate even play a role in length?... Arg, I'm confusing myself. I just need a book, a few thousand rounds, and practice.

Irving
12-08-2009, 15:00
That's a question for SA, I have no idea on that one.

SA Friday
12-08-2009, 15:34
ok, I didn't ask correctly... Let me try to clarify. I understand there is no contact between bullet and suppresor. What I am asking is:

1. With a shorter barell, will I lose accuracy.
2. With can on and off, with a shorter barell will there be a more distinguished POI?
3. If the barell is long, made even longer with a can, then don't I run the risk of loads not exiting the barell?...

Thxs.
1. Cutting your current barrel shorter will change the harmonics of the barrel. It's impossible to tell if this will affect the accuracy, but more than likely it will affect how it shoots ammo in comparison to it's current length.

2. The POI while using a suppressor will more than likely be a different location than when shooting without it. Almost everyone I've known to shoot a high powered rifle says this. They also say that the POI with and without the suppressor are repeatable and usually equal in accuracy. Sometimes, the suppressor actually tightens up the group. This is one of those, 'gotta test it' things.

3. No way. Even if your powder is burning out before it reaches the end of the barrel, you are only losing a LITTLE bit of velocity; i.e. 2850 fps instead of 2950 fps. Like I was saying, it only matters on 'way the hell out there' shots, and if you find a slower powder that shoots accurately in a reload for the gun, the extra barrel could actually result in faster velocities. Don't get wrapped up into your barrel length. I mentioned this in passing, it's gee-wiz info. Optimum barrel length is nothing to get wrapped up in.

At the very experienced levels of shooting, guys optimize every little aspect of their rifles to squeeze any and every tiny little advantage out of the gun. The results are amazing... and very expensive. I've seen and shot rifles like this, and I'll tell you for free that they are amazing and as addicting as crack cocaine. High end stocks like McMillian and HS and AI; custom built actions and bolts hand fit to the stock, stock bedding jobs so perfect you can't believe someone can do it; barrels custom made with brand new rifling reamers and chamber reamers so there isn't any wear on the reamers when the barrel is cut; $3k+ scopes on custom mounts built into the action instead of being screwed on to it; 6 to 12 oz triggers; etc etc. Crack Cocaine...

Shoot what you have. Learn the important stuff, trigger press, sight calculations, doping the wind, reloading for the gun. Then go for the crack pipe.

Hoser
12-08-2009, 18:36
1. With a shorter barell, will I lose accuracy.
2. With can on and off, with a shorter barell will there be a more distinguished POI?
3. If the barell is long, made even longer with a can, then don't I run the risk of loads not exiting the barell?...

1. 99% of the time, no. A good bore and crown are key.
2. A short barrel is normally a little stiffer and you wont get as much "barrel droop" from a can.
3. Nope, not even with subsonic loads. Unless you find a 15-20 foot long barrel, then all bets are off.

BigBear
12-08-2009, 20:57
SAFriday, thank you. As always very informative. I still owe you dinner or something sometime.

Hoser, thank you also. Question for you though: You mentioned "barrel droop". Is this the phenomena I've been reading about where a shooter fires too rapidly and warms the barrel to where the weight of the can actually bends the barrel resulting in tumbling, baffle strikes, etc?

Bottom line, ignore nuances, learn to shoot my firearm, learn to reload, wash and repeat. Rgr, thxs all.

theGinsue
12-09-2009, 01:02
BigBear

In regards to your original question, it's almost like asking identical twins what their favorite flavor of ice cream is - though they look identical, you'll likely get two different answers.

What I'm saying is that two identical rifles, same make, model, caliber, producted one right after the other on the same equipment will shoot identically produced rounds with varying degrees of accuracy. One of these rifles may shoot dead on while the best you'll get out of the next is 1/2" group. This is caused by several factors, notwithstanding the harmonic resonance of the barrel itself. In fact, in my humble opinion, this is the most significant factor.

When I reload with different components from previously developed loads (using a different bullet, or case, or primer), I always "bracket" a range of different charges to find the one that works best for MY gun.

My best friend and I reload .30-06 cartridges together for our hunting rifles. We've found, with the current components we're using, that his rifle shoots great with 2gr of powder less in the cartridge than my rifle needs to get the same results.

In regards to factory ammo, I won't ever use Winchester ammo in it again as I can't get consistent grouping out of any of their cartirdges. Remington Cor-Lok's have given me fairly consistent tight groups (as much as can be expected for factory ammo).

Just my $.02.

BigBear
12-09-2009, 09:24
Thank you Ginsue, much appreciated... can you talk to me about this harmonic resonance you are mentioning. Anything close to musical resonance?

I am a musician (even have a MM in music, lol). On a trumpet, the passage of air hits certain nodes inside of the bends of the pipes and produces a vibrating effect. This vibration gets amplified to the bell of the insutrment which produces the bright characteristic trumpet sound. If a trumpet is sounding "bad" there are only two possibilities: 1. The musician sucks (most common, lack of fundamental knowledge on the physics of the horn), or 2. bracing and other solder joints on the trumpet are not placed in the optimum area for least harmonic resistance (least common as the basic design and materials for modern trumpets have been around a few hundred years, the ancestry of trumpet goes back to the beginning of time).

Or the vibrations in the air, such as taking a glass wine glass, figuring out the frequency of that glass, and playing the frequency (note) at a certain distance from the glass for a certain amount of time, making the glass vibrate and eventually crack. http://www.youtube.com/watch?v=Pq-PxdOarjA This is Dr. D. (Nick Drozdoff) He's a beast on the trumpet. Physics teacher out of Chicago, full time pro player at night.

There is even harmonic disruption in rooms... such as the echo in a cement room or the "dead" sound in a room full of carpets, etc... So relating to firearms, I'm assuming the spinning contact of the bullet against the barrell is creating some sort of vibration? I have seen big rubber type balls that pro long distance shooters put on their barells sometimes.

Hoser
12-09-2009, 10:15
Hoser, You mentioned "barrel droop". Is this the phenomena I've been reading about where a shooter fires too rapidly and warms the barrel to where the weight of the can actually bends the barrel resulting in tumbling, baffle strikes, etc?




Nope. You are hanging a 1-2 pound weight on the very end of a pipe that is only supported buy the opposite end. The usual result is a lower POI at distance.

If you get a baffle strike, most of the time its from impropper threading or an understabilized bullet.

BigBear
12-09-2009, 10:28
... or an understabilized bullet.


Understabilized?... not enough grain, etc? What does "understabilized" mean? Thanks for explanations.

SA Friday
12-09-2009, 14:35
Understabilized bullet is usually too heavy a bullet being shot out of a barrel with too slow a twist, but there are other reasons a bullet doesn't stabilize. It comes down to the bullet leaving the barrel spinning like a really nice thrown football or a wounded duck thrown football. The wounded duck looking pass is essentially what an unstabilized bullet looks like. Stay within the reloading charts and test rounds without the supressor first. You will see the round tumbling or not flying true on paper as it will leave a keyhole like hole in the paper. Like I said before, with a 1 in 12 twist you are good up to 180gr bullets and might be ok with 200's, but if 168's shoot groups like you say, why change. Hoser may have additional info on this about shooting a suppressor. He has tons more experience with high powers and suppressors than I do.

You ever see the old cartoons where the character shoots bullet out of the cartoon gun and the barrel twirls in a circle as the bullet travels down the barrel and then the crown spits the bullet out? Well, ironically thats kind of what happens in a real barrel in a much less obvious way. This is barrel harmonics. It can also be described like a tuning fork. You take a tuning fork and the unconnected part of the forks vibrates back and forth. The part of the forks attached to the handle don't move. You can tap the fork lightly and see little to no movement or you can slam the fork and see the end of the forks move a lot. Accurate rounds cause barrel harmonics where the bullet is leaving the barrel at the same point in the vibration every time. Other things harmonics cause is how the rounds pattern on paper. You can see circular patterns and string patterns. When working reloads, if I get a pattern of bullets on paper that strings and then another pattern that's circular, I'll work the bullet and powder combo that was circular to find an accurate load. The string patterns, I will disregard the bullet/powder combo. I've tried to work them up and down with powder amounts and have found that if the combo strings it just won't tighten up. I'm not positive, but I'm pretty sure this is also from barrel harmonics. It's like the barrel is going back and forth instead of in a circular vibration. The circular vibration is controlable but the back and forth is a crap shoot as to when the bullet will leave the barrel. That's my theory anyway.

Ginsue, That's really funny that you mentioned Rem Core lok ammo. A shooting buddy and I were discussing the best cheap ammo to sight in a gun with the other day and I instantly told him the same. I use it to initially sight in all my new guns with. I have yet to find a gun that doesn't shoot this stuff really well for factory ammo. In some it shoot less than MOA. I've never had any luck with most of the Winchester rifle rounds either. The only one I've found accurate is the Winchester Supreme .223 with a 50gr Nosler Balistic Tip. The rest are all over the place.

BigBear
12-09-2009, 15:12
You ever see the old cartoons where the character shoots bullet out of the cartoon gun and the barrel twirls in a circle as the bullet travels down the barrel and then the crown spits the bullet out? Well, ironically thats kind of what happens in a real barrel in a much less obvious way. This is barrel harmonics. It can also be described like a tuning fork. You take a tuning fork and the unconnected part of the forks vibrates back and forth. The part of the forks attached to the handle don't move. You can tap the fork lightly and see little to no movement or you can slam the fork and see the end of the forks move a lot. Accurate rounds cause barrel harmonics where the bullet is leaving the barrel at the same point in the vibration every time. Other things harmonics cause is how the rounds pattern on paper. You can see circular patterns and string patterns. When working reloads, if I get a pattern of bullets on paper that strings and then another pattern that's circular, I'll work the bullet and powder combo that was circular to find an accurate load. The string patterns, I will disregard the bullet/powder combo. I've tried to work them up and down with powder amounts and have found that if the combo strings it just won't tighten up. I'm not positive, but I'm pretty sure this is also from barrel harmonics. It's like the barrel is going back and forth instead of in a circular vibration. The circular vibration is controlable but the back and forth is a crap shoot as to when the bullet will leave the barrel. That's my theory anyway.


Very cool analogy. Again thank you. Understood.

Hannu
12-12-2009, 00:33
With 12" twist, you can use all target bullets to 180-190 grain weight. It depends on if your barrel actually has 12.0" twist, or 12.4" or 11.5" and the lenght of the bullet.
You can use short 200gr hunting bullets with 12" twist as good. Twist rate needed is not depended of bullet weight, but bullet lenght compared to caliber.

With .308 subsonic ammo, you are gonna have bullet stuck in the bore sooner or later with barrel longer than 16". I have experienced that with Lapua factory ammo, that is why they recommend barrel no longer than 16" for subsonic ammo ;)

When proper silencer is properly installed and all is otherways ok with the rifle (bedding, barrel quality...), silencer does not affect on group size so you could tell the difference in average group size. It usually only changes point of hit a bit.
However, silencer may improve accuracy if, for example, forged barrel is not best possible quality.