Tune ammo?

[rbahri5206]

I am very new to reloading I understand how to do it and have made a couple hundred rounds that I have shot already with no problems but my question is I keep reading about tuneing ammo to your gun and making your rifle shoot more accurate I'm just wondering if I can more information about how I start to doing this and what I can achieve and what steps I need to take.

[CalTeacher]

I am very new to reloading I understand how to do it and have made a couple hundred rounds that I have shot already with no problems but my question is I keep reading about tuneing ammo to your gun and making your rifle shoot more accurate I'm just wondering if I can more information about how I start to doing this and what I can achieve and what steps I need to take.

Experiment with different powders, powder charges, bullets, bullet weights, brands of brass, seating depths, primers, crimp diameters/no crimp, etc. Until you find the combination that shoots the best out of your particular gun.

[sofbak]

In a nutshell summary, here is how the process worked for me:

Took my first 96 colt reloads to the range today and ran them through the "new" vaquero. Four loads of trailboss, and four of unique. No issues, no catastrophes either. All shot well, but you could definitely tell when you got to the load that was the "sweet spot" for this gun.

Not only did the grouping improve noticably, but I could feel the difference in my hands! The gun just seemed to respond a bit "tighter" or crisper with the good load. This happened with both powders.

[OldShooter32]

First thing I would do with a rifle is measure the throat length. CLEAR the weapon, then run a rod down until it touches the bolt face. Mark the rod at the muzzle.
Next, drop one of the same kind of bullet you plan on seating into the chamber and hold it lightly against the throat with a pencil or rod. Run the cleaning rod down until it touches the bullet tip. Mark the rod at the muzzle again. Now measure between the two marks and you have seating depth. You may want to seat a couple thousandths deeper to ensure clambering, but try different depths until you get the best group.
Measure the twist rate too -- flag a cleaning rod with a piece of tape and run it down the bore until it has completed one turn. Measure how far it traveled and you will have your twist rate. Research the best weight of bullet for that rate and then spend time on the range finding out which works for you. Buy a chronometer!! It will save you grief!

[rbahri5206]

First thing I would do with a rifle is measure the throat length. CLEAR the weapon, then run a rod down until it touches the bolt face. Mark the rod at the muzzle.
Next, drop one of the same kind of bullet you plan on seating into the chamber and hold it lightly against the throat with a pencil or rod. Run the cleaning rod down until it touches the bullet tip. Mark the rod at the muzzle again. Now measure between the two marks and you have seating depth. You may want to seat a couple thousandths deeper to ensure clambering, but try different depths until you get the best group.
Measure the twist rate too -- flag a cleaning rod with a piece of tape and run it down the bore until it has completed one turn. Measure how far it traveled and you will have your twist rate. Research the best weight of bullet for that rate and then spend time on the range finding out which works for you. Buy a chronometer!! It will save you grief!

Im a little confused is there any video or pics anywhere on doing this?

[mroels]

I'm a newb to reloading like you but not to shooting. Essentially it's the same concept as figuring out what factory ammo your guns like. I only reload .223 right now. My rifle loved BHA 68gr ammo. There are plenty of threads on various forums speculating on what powders/bullets/primers your favorite ammo uses. Keep in mind that these types of recipes are really just speculation so cross reference load guides. For me I didn't want to spend a ton of money on gadgets so I experimented. First I bought the components that people said were used in the BHA ammo my rifle likes. Then I measured the factory ammo to find the OAL. And initially just tried to replicate it.

Basically I loaded different quantities of powder in each case. Every 5 rounds I upped the charge by .1 grains. And seated the bullet to the same depth as the factory ammo. The I went to the range and shot 5 round groups of each of the charges as well as a 5 round group of the factory ammo as a baseline. I used the round robin method, which youll have to google. With the factory rounds my rifle always shot around. 75" at 100yds. With the rounds I charged I found that using 22.7gr-23.3 grains the rifle shot .6" at 100 yds. So I knew that my rifle was more consistent in the barrel harmonics with those charges.

Next time around I loaded more rounds in batches of 10 of each of those favored charges to really find the sweet spot. Which turned out to be 22.9 grains. Then I played with the seating depth and OAL. I loaded 3 round batches using 22.8-23.1 grains at different depths in .05" increments and again tested with would shoot the best group. Once I figured out the best combo I had ammo that was "tuned" to my rifle.

Of course it doesn't stop there. Because once you find that ideal combo you're gonna start with changing how far to set to shoulder back to seal your chamber better. Then youll want to tweak the velocity for longer ranges without losing accuracy..for this you'll need the chrono.

Once you think you've got it all figured out you'll read about a better powder and start the whole process all over again. Then you'll want to try a different brand bullet and do the whole thing again...new primers...new brass....new with old...etc etc etc.

You see that this is why people say you don't save money reloading. You'll be old before you really find the best combo. And by the your barrel will be worn out and you'll do it all over again for your new rifle.

Ps. I don't chrono anything until it's proven to be an accurate load.. If it isn't accurate I don't care about the velocity.

[OldShooter32]

Im a little confused is there any video or pics anywhere on doing this?

Not that I know of. The process is simple, though my explanation might not be. Perhaps I will enlish a techie to video me doing it. PM me with specific questions about where you got lost and perhaps I can resolve them.

[Pthfndr]

Im a little confused is there any video or pics anywhere on doing this?

This is the method he's talking about. In the video the person is using clamps on the rod, but you can use a sharpie, or masking tape, etc.

http://www.youtube.com/watch?v=9OZ8u8e7mSc&feature=related

[huckberry668]

It took me years to figure out how 'tuning the load' really work. I started 20 years ago and not much to find on the Internet. Since you're new to this, I'll start with the basics I found in the order of complexity and accuracy gains vs. investment.

the following is assuming you'll be using match grade components. Military pulled or thrift components most likely won't yield the highest level accuracy.

1. Tune your rifle. At least basic action work - bedding it (bolt, M1A, Mini14/30s, remove action wobble (ARs), trigger job (weight and over-travel). It's useless to tune ammo if your rifle's mechanics doesn't allow for repeatable precision. properly torque all screws, bolts and remove parallax from scope. And of course you need a good set of rifle rests and rear bags (besides your skills).

2. Basic brass tuning - start with basics, brass preparation. Sort brass by head-stamps, trim length, uniform the primer pockets, debur the flashholes will gain you measurable accuracy from any load without too much investment in tools.

3. More advanced brass tuning - bump the should back .001" to .002" if you full length size. Neck size will ensure your rounds seals the chamber to the best possible level and least amount of 'vibration' and prolongs brass life. The next level would be turning the necks to a uniformed thickness.

4. Bullet seating - this is where the measuring throat length comes in. Seating the bullet touching the rifling is where I usually start with. But I always starts from the minimum load and work it up till i find the sweet spot.
Get one of these:http://www.midwayusa.com/product/231...with-6-inserts

Resize a brass and make youself one of these:


insert a bullet in the mouth just barely and slowly push it into chamber by hand till dead stop, carefully push out with a rod and measure the ogive to the base length and that's the length at touching the lands of rifling (for that particular bullet). Seat the bullet into the lands or off the lands to 'tune' for the best seating depth.

5. Powder and primer makes the least amount of differences. Start with the minimum from the load data manuals and work it up. Buy the powder that allows for the most flexibility like Varget, Reloader15, IMR4895 etc to work you best load from.

6. even higher level of tuning - separate prep'ed match grade brass by weight, separate match grade bullets by weight and ogive length.

i'm sure i missed somethings others find useful. but this is what I found to be the process in the quest of better accuracy from ammo.

[OldShooter32]

This is the method he's talking about. In the video the person is using clamps on the rod, but you can use a sharpie, or masking tape, etc.

http://www.youtube.com/watch?v=9OZ8u...eature=related

And he is better-looking than me...

[RandyD]

In tuning your reloads, there are numerous factors to consider and this topic cannot be addressed in just a few paragraphs. What I recommend is reading the reloading subforum on 6mmBR.com. The reloaders on that site are benchrest shooters and they are the experts at tuning their loads to maximize the potential accuracy. I took the time to read every post on the reloading subforum and there is a lot of information, and the members on that site welcome questions.

[RandyD]

I just checked the reloading forum on 6mmbr.com, it has 384 pages, 7667 threads and 60820 posts. Like I said earlier, you will learn a lot and there is a search function. No sense recreating the wheel when one exists that you can use.

[bubbapug1]

A large part of "tuning" a load is actual tuning...like you tune a piano.

Look at your barrel as a tuning fork. It vibrates with each shot, and that vibration means its moving back and forth between two points (its not truly linear however). The trick is to find a load that exits your barrel near the end point of one of those osciallations where a unit of time has the least imact on the actual angle of movement of your barrel.

The other aspect of tuning is to remove all non equal loads which would impart a moment on the barrel, thereby decreasing the vibration of the barrel. That's why you have free floating barrels, trued actions, etc. Those unequal loads create harmonics which make the barrel vibrate, so the least amount of vibration equals a more consistant exit point of the bullet.

Lots of things create vibration, and you can't escape them, but you can minimize them. Ever notice benchrest rifles and F class rifles have thicker barrels? Thicker barrels aren't as "whippy" as some other barrels although they still move. Fluted barrels also can have issues because or the stresses induced by the machining of the flutes. The stresses will react to heating of the barrel, causing them to bend from the zero point. Not all fluted barrels do so, and are treated to relieve the stresses created in the machining process.

Some of the other things people mention above have more to do with ammo consistancy than actually tuning...

Like brass...the issue with brass is you want it to be equal in volume (boyles law) so you get equal pressures for a given powder charge. You also want uniform necks to insure the bullet is concentric in the barrel, as bullets can and do enter the barrel cocked...and that affects accuracy. There is a belief that brass that weighs the same also has the same internal volume, its a valid assumption but its not true. One study has shown that cases which are filled near maximum consistantly produce a given velocity than those which are partially filled. This may be due to flame propogation properties of powder granules in close proximity are more conistant than propagation in random geomitries, I am not a flame and gas propagation expert, but I do note tighter chrony strings when I have full cases of powders.

Bullet seating...the idea there is to get the bullet to be centered in the throat of the barrel. If you jam load your bullets, and the brass fits perfectly in the chamber, and the bullet is centered in the brass, technically the bullet will be staight into the barrel...if in fact the chamber has been reamed with a piloted reamer and is concentric with the barrel!!! Many barrels aren't, so the bullet has no chance to enter the barrel straight no matter what you do unless you drop it in and than seat the case in the chamber!!!.

There are many tricks and procedures for reloading highly accurate ammo, some which actually work, and some of which are urban myths.

The trick is to load each bullet consistantly, use a primer which is seated the same way and has characteristics for the powder and caliber you want, and to use high quality bullets, like SMK's, bergers, or Nosler match.

The best single work on how to tune a rifle and ammo is called "Rifle accuracy." The rest of the books I have read on the subject have been long on urban myth, and short on empirical data and scientific method.

http://www.amazon.com/Rifle-Accuracy-Facts-Harold-Vaughn/dp/1931220077/ref=sr_1_2?ie=UTF8&qid=1343695930&sr=8-2&keywords=rifle+accuracy

Its pretty heavy on math, but if you suceeded in statics or took a college physics class you will be able to follow it. if not you still will understand the summaries of each experiment and grasp the basics behind a good gun and a great gun.

Just don't post you have attained 1/8" MOA with your stock AR 16" carbine or we will call you out for what you are....a liar.

[rbahri5206]

This is the method he's talking about. In the video the person is using clamps on the rod, but you can use a sharpie, or masking tape, etc.

http://www.youtube.com/watch?v=9OZ8u...eature=related

great video thanks i understand the steps, thanks to everybody for pointing me in the right direction

[Knife Edge]

I am very new to reloading I understand how to do it and have made a couple hundred rounds that I have shot already with no problems but my question is I keep reading about tuneing ammo to your gun and making your rifle shoot more accurate I'm just wondering if I can more information about how I start to doing this and what I can achieve and what steps I need to take.

Go to an indoor range and shoot loads from minimum published value in .5g increments until you get within 1.5 of published max. Then switch over to .3g increments and approach "your rifles" maximum cautiously. Determine maximum via overpressure signs, sound, etc. You have also determined maximum velocity, however not necessarily most accurate. In order to determine an accurate load that is faster than an equally accurate load but much slower:

After determining maximum load, back off .2 grains and build 10 round groups in .2g reductions until you get to the lowest muzzle velocity that is acceptable. You can reference charts for velocity or use a chrono which is preferred. Of each 10 round group, shoot a 3 shot group at 100, another at 300 and save the rest for the chrono. Work down in pressure until you find the group that all of sudden looks really good , that's the easy way. I've found best accuracy around .5g under max (not charted max, max that I have determined) in several applications, just a shortcut if you are in a hurry. Please keep in mind, I shoot XBR 8208 which is extremely temperature stable. Using the above method with minimal margins with BLC-2 can lead to disaster if you work up a load in a cool winter and shoot sun soaked rounds in the summer.

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