Help a Noob

[Noah]

You guys are awesome... Thanks a ton for the advice! I don't take you all correcting my ignorance personally I appreciate it very much.

Can someone recommend a better manual because I am beginning to think this lyman book sucks. I have been thinking about OAl after seating a few Sierra GK(which was not in my manual) bullets without adjusting my die from the MKs. Thinking that it looked so similar to the MK that the same die adjustment would seat the bullet the same depth into the case. NO, it seated it much deeper. I found out that that the two bullet have a different og. and I am wondering how to figure out what is the proper OAL for bullets not in my book.
Should I seat to the max OAL that fit in the mag? I read that bolt shooters try to get the bullet right at the rifling but is there ever a situation where the extra space in the case is bad? like might be possible with the shorter GK.
I figure the ones I seated too far in need to be disassembled; but what about the other way? can a bullet be seated to far out(while still fitting the mag and chamber)?

As for the rounds I already made I was not able to make it to the range this weekend so I will make more at each weight as to not waste time.

Popeye,
I read somewhere else someone recommended a BC weight that Tubb makes? Do you know anything about that and if it would be anything that would benefit my setup?

Thanks again
Noah

[tamalpias]

Just my experience but I found out that I have yet to see any huge significance in seating depth of bullets. I tried that out to .01 of an inch from the lands and grooves and seated in the max OAL by the books and found an unnoticeable difference.

[ar15barrels]

I would shoot groups at 300 and 500 to check for best accuracy.
Wait for a day with as little wind as possible and shoot your ladder test.
100yds really does not tell you much.

I shot ladder tests at 500yds and 840yds, but it was windy on the day we shot the 840.

[ar15barrels]

Just my experience but I found out that I have yet to see any huge significance in seating depth of bullets. I tried that out to .01 of an inch from the lands and grooves and seated in the max OAL by the books and found an unnoticeable difference.

What bullets?
Secant ogives will show more change with seating depth than tangent ogives.

[Noah]

Randall,
Would you suggest shooting at a shorter distance if there is a breeze? This time of year my range usually never sees a totally calm day. Is 200 or 300 enough for a 168 to settle in well? I'm 20" barrel with 1in12

[freakshow10mm]

Here's how I do it for my rifles and my commercial rifle ammunition:

Set your OAL first. Then start at the start charge and work up in .5gr increments, 4rd groups. 3 for group and one to call operator error. Here you are looking for group size and pressure sign.

Then go back and go .1gr increments between the most accurate halves.

Say you ran from 45-50gr but 48gr and 48.5gr were your smallest groups. Start at 48gr, then in .1gr increments load and shoot 5 rounds for group. Smallest group, chrono for 10rds noting accuracy, if satisfactory, THAT'S your load.

[popeye4]

Here's how I do it for my rifles and my commercial rifle ammunition:

Set your OAL first. Then start at the start charge and work up in .5gr increments, 4rd groups. 3 for group and one to call operator error. Here you are looking for group size and pressure sign.

Then go back and go .1gr increments between the most accurate halves.

Say you ran from 45-50gr but 48gr and 48.5gr were your smallest groups. Start at 48gr, then in .1gr increments load and shoot 5 rounds for group. Smallest group, chrono for 10rds noting accuracy, if satisfactory, THAT'S your load.

[ar15barrels]

Randall,
Would you suggest shooting at a shorter distance if there is a breeze? This time of year my range usually never sees a totally calm day. Is 200 or 300 enough for a 168 to settle in well? I'm 20" barrel with 1in12

The wind does not really screw with the ladder that bad unless your target backer is too small.
The further the better with the ladder as you want to see larger changes in vertical dispersion with each shot.

When I shot the 840yd ladder, I had 4 rounds land within about 2" vertical dispersion.
This was with 0.1gr steps.
The other rounds outside of that range were making 2"+ steps up and down the target backer.
So I picked the charge that was right in the middle of those 4 rounds.

The shorter the range that you shoot the ladder, the less defined the steps will be.

[thomashoward]

popeye is using the ladder approach , I myself would load 6 rounds at each weight and shoot 3 shot groups and move up in .5 increments . I use the 3 shot groups to test the load , When i find the best of those i load 10 rounds of it along with 10 -.2 and 10+.2 and then with the best of those i start working on seating depth.

+1 that's it
if you load more then 5 rounds of a load and its crappy, you wasted components. I start in the middle range of the listed data and load 5 rounds. The go up .5 grains load 5 more. keep going until you are near Max but not over. Shoot these for groups to get your load. You can fine tune from there buy going up or down by .3 gr then, check seating depth and tinker with that. By all means get a notebook and write all these results down so you can duplicate the loads

this is how you measure seating depth

http://www.hornady.com/story.php?s=485

[Noah]

Thanks again everyone for the continued input. Every bit of advice is much appreciated.

Regarding OAL: you aren't really concerned with OAL for accuracy, you just need to get the rounds in the mag. For improving accuracy, you are more concerned with where the bullet contacts the barrel lands and how far it has to "jump" to get there (consistency is the key). Match bullets in particular can have significant variations in the distance between the tip and the barrel contact point. Match seating dies therefore have the seater plug hollowed out so they touch the bullet where the lands of the barrel would touch, providing more consistent jump to the lands. Does it matter? As Randall pointed out, it depends alot on the bullet. Sierra MKs (tangent) are much more forgiving of jump than VLDs (secant), but the VLDs have lower wind resistance and can therefore perform better at long range.

But if you seat your bullets to touch the lands, you need to back off on the powder charge as that condition can really make pressures jump.

Fine tuning bullet seating depth can make a good load better, but it is getting pretty advanced for a beginner. You should get some measuring tools to determine exactly what you are doing when you get to this stage.

So should I seat the Game Kings to max OAL for the mags? because from my measurements that will create much more volume in the case than the MKs at this OAL. I am not that worried about accuracy affects of OAL at this point I just don't want to damage my rifle or myself with over pressure situations. Also, for curiosities sake... If seating out to the rifling lands can create more pressure what are the affects of seating too deep into a case? Less pressure or more pressure also???
I have studied some elementary physics but I am not grasping how more volume in the case makes more pressure with the same amount of powder.

Noah

[freakshow10mm]

Accuracy isn't cheap.

I've worked up a load for my particular M14 that will hold the x-ring (when I can) through darned near 1 grain variation in powder charge. I don't concern myself with the small variations I get from a powder dispenser.

1gr variation is unacceptable in any capacity.

Regarding OAL: you aren't really concerned with OAL for accuracy, you just need to get the rounds in the mag.

This above contradicts this below:

For improving accuracy, you are more concerned with where the bullet contacts the barrel lands and how far it has to "jump" to get there (consistency is the key).

Like I said, set your OAL first.

But if you seat your bullets to touch the lands, you need to back off on the powder charge as that condition can really make pressures jump.

Like I said, set your OAL first, then start at the start charge and work up.

Fine tuning bullet seating depth can make a good load better, but it is getting pretty advanced for a beginner. You should get some measuring tools to determine exactly what you are doing when you get to this stage.

Load to the longest that will fit in the magazine and still chamber safely. Not hard to do.

[thomashoward]

Quote[So should I seat the Game Kings to max OAL for the mags? because from my measurements that will create much more volume in the case than the MKs at this OAL. I am not that worried about accuracy affects of OAL at this point I just don't want to damage my rifle or myself with over pressure situations. Also, for curiosities sake... If seating out to the rifling [lands can create more pressure what are the affects of seating too deep into a case?no accuracy,most books have an OAL legnth listed Less pressure or more pressure also???less than to the lands
I have studied some elementary physics but I am not grasping how more volume in the case makes more pressure with the same amount of powder.] look up "pressure incursions" ,I think its called. Like backflash]

I would set the bullet off the lands for accuracy then check before loading a bunch to see if they fit the magazine,using a comparator so you know a number to write down that you can duplicate later.
Most rifles have a sweet spot around .005", .018",or about .027"off the lands.
I always start close from .003 to.005 off the lands and check. I did mess up once and my .270 rounds hung up a little in the magazine. I seated them deeper when I got home so they would function.
Also when you use the comparator and see the measurement to the lands with a given bullet, this is your baseline for checking erosion later, and to adjust the seating.

[popeye4]

1. I don't accept 1.0 grain variations, but the load was relatively tolerant of that range. I can usually get a 0.2 grain variation using VV powder on my Dillon press without too much trouble. Trickling powder for several hundred rounds just doesn't work for me.

2. I'm trying to make the point that consistent OAL doesn't necessarily reflect consistent jump to the lands, particularly with match bullets (I probably could have stated it better). Also, different bullets have different profiles, so inferring jump from OAL just doesn't work consistently. For the rifles I've got, (M14 and AR15), I can't get into the lands and still fit the round in the mag. Therefore, getting wrapped up in varying the jump a couple thousandths doesn't affect my mag length loads (for long range slow fire stages, I single load and the mag length doesn't factor in). I also consider that to be more advanced reloading technique and one should have the proper measurement tools and understanding before getting close to the lands. For example, I've measured my rifle chambers and know the distance from the shoulder to the leade. I also can measure the distance from the shoulder to the bullet datum line (that touches the leade), but that's a whole set of instruments needed to do so. But then, that's part of the fun of this hobby, there always seems to be one more step one can take to better ammo. I should have made that clearer, as well.

3. Yes, jump can affect accuracy, but you should only change one variable at a time. I prefer to get the powder charge close first, then fine tune the jump. My experience is that the jump variation doesn't have as much impact as the powder charge does to getting consistent loads (but that's in my rifles, YMMV). But it does tend to be somewhat of an iterative process (that's why I stick with one load that works, once I find it).

4. Regarding ranges tested at, again it should be at the range you plan to shoot at. Most benchresters don't shoot beyond 200 yds (and the majority of their shooting is done at 100 yds). They use components that excel at that range, but would probably suck at 600+ yds. They do shoot really well at those short ranges. Randall is a long range shooter, so he is justifiably unconcerned with data obtained at 100 yds (it might actually give him erroneous info). He also probably has a place to shoot long range (I'd have to drive at least 3 hours to get to a 1000 yd range, and then I'm not sure I could do load development there). Therefore, he does his load development at the range he plans to shoot at.

5. When shooting at long range, the wind dispersion is horizontal. The ladder dispersion is mostly vertical. A good long range shooter can (must) read the wind and tell when the wind pushed his shot. That's why Randall can shoot ladder loads at long range, he's already a good enough rifleman to eliminate (or at least comprehend) the long range variables and factor them into his results.

I hope this clarifies my earlier posts.

[popeye4]

And if you simply have to have the best: http://www.6mmbr.com/prometheus.html

[oldcodger44]

I want to thank you guys for all the info too. I learned a thing or two also. The only thing I would add is a manual called loadbooks. I think I bought mine from Midway a few years back. Anyway it is a compilation of loads from every reload manual out there for 1 specific caliber. It's a good reference for me. I just checked and you can buy them direct from loadbooks.com. .308 is 10.95 with the shipping included.
hope this helps