Seating problems

[ColWhitecakes]

I am having problems with seating consistancy in my .308. I measure and sort the bullets by length, and set up my die with a max length dummy round seated push in to the lands. I then seat a bullet in a charged case at this length and then incrementally adjust the die untill it is the final depth I want. However, the next roumd may be exactly the same, or shorter or longer, at least COAL. I know that there is some bullet inconsistancies at play, but how do you avoid this? I know that the die is applying the seating pressure about about 3/16 from the nose of the bullet, and I always reasoned that was most likely the least consistant area of th bullet, so I bored out insert as large as I thought I could get away with and now it is applying pressure a lil over half way down the ogive towards the bearing surface. I still get the same results.
What is the best approach to solving this problem? Do I need a micrometer seater and do each round individually? I am currently using a Lee die, and 168gr Amax.

 

[jo191145]

I get the feeling your measuring COAL and judging by that. That measurement will always vary.
If you are in fact using a comparator and still getting large variations make sure your modified seater plug is not making contact with any tips on the bullets.

What bullets are you using?

 

[amlevin]

The 168 A-Max is a real consistent bullet for OAL length as well as base to ogive measurement. In your case I think it's the die that's the issue. I would find a washer that will fit around the case. Insert the case in your shell holder, place the washer around the case, then adjust the die so it contacts the washer before the ram "cams over". Then adjust the seater plug so the OAL is what you desire. This will create a Dead Length Die which will eliminate any variations in where the case sits when the seater plug inserts the bullet.

I wouldn't worry too much about slight OAL variations if the finished round measures the same when using a comparator. In the end, this dimension is the one that matters most in your rifle, the distance from the ogive to the lands, not the tip.

 

[devildogandboy]

my 2cents, you are measuring the overall cartridge length which will vary considerably with different bullets, try using a comparator and measuring off the ogives, this will give more accurate measurement. good luck.

 

[ColWhitecakes]

Here is the procedure I used:
I measured the OAL of a 100 rnd box of 168gr Amax and sorted them by the result.
There was only three sizes that resulted (and bear with me if I am a lil off cause I am going by memory),
1.113, 1.114, 1.115, of which over half were .114 and only about five were .115.
I then proceeded to load ten rounds. I can't remember right off which ones I used, but they were all the same OAL.
I have a Lee seating die. With it in my press with the top removed and the seating stem/plug out, I place one of my cases in the shell holder, raise the ram to its full up position, and screw the die down just until it comes to rest very slightly snug against the case mouth. The die its self never touches the shell holder.
I then remove that case and put in my dummy round, place the plug on top of the bullet and then screw the top on until it makes firm contact with the plug.
I then seat a bullet in a freshly charged case and measure the COAL. I realise that it is not the best way to judge distance to the bearing surface, but is currently the only way I have to judge. I adjust the die down slowly until that bullet is seated the distance I want, and load another one to this setting. My usual result is it MIGHT be the same as the first one, or it is longer or shorter, but usually longer.
I determined, which was easy enough to do, that when the bullet is being pressed in to the case, the plug is applying the pressure pushing it downward at a point roughly 3/16" to 1/4" from the tip.
I always surmised that the right close to the tip is likely where most bullets vary the most in their dimensions, due to them being swaged or formed that direction, and the pug pushing from this area is causing a lot of the variance. So, I removed the plug and bored out the hole out as large as I thought I could get away with. Now it pushes the bullets from a point a lil past halfway from the tip, or, closer to the bearing surface.
This yield me the same results, and as best as I can figure, most every seater I've seen applies pressure in the same general area between one of the ones I have mentioned. But then again, wouldn't that leave evreyone else with the same problem? It seems that even if I measured and sorted bullets with a comparator that measured from the bearing surface, when I seated the bullets, I would still have the variance that is the difference in dimensions from where the pressure was actually being applied. Isn't that correct? Is there a die that seats closer to the bearing surface? Or is the remedy seating the bullets slightly long, and then using a comparator on each round and seating them all individually (like with a micrometer seater for ease) until they measure the same length with the comparator?
I did also use the plug as a comparator to measure some of the sorted bullets. I found slight variations amongst them, even though OAL-wise, they were the same. I would have to double sort bullets, and that would be a major PITA, but is that what I need to do?
Keep in mind that I realise my equipment is a lil under par, as far as where I would like it to be. I'm fairly new to this, and I am slowly but surely working to acquire better tools as I can, so I welcome honest opinions and tips towards equipment replacement/recommendations, especially if it will help keep me from making the wrong investment.

 

[jo191145]

#1
A seating die should not make contact with the case mouth.
Find your longest case. Screw die down until it makes contact "just as you have been"
Now back it out one half turn and set the collar. Leave it there forever.

Place your dummy rd in the press and insert your plug. Take note of COAL.
Screw that plug in tight against the dummy. Measure, if its still the same length lower ram, turn plug down just a smidge and reseat.
I'd be aiming for shortening your dummy rd .001"
Once you accomplish that don't move it!!!
Your seater will do the job better than you can without the proper measuring tools.
If you decide you want to change seating depth I'd suggest you remove the die from the press, measure the overall length of the die and adjust the seater plug in the desired direction and amount and reinstall.

Without a comparator your just measuring in the dark. Once you get a comparator then and only then can you even begin to question the validity of your seater.
The above instructions are not considered the proper way to go about things. They simply will give you better results "today" until you can get yourself a comparator and have the ability to judge your seater correctly. It may indeed be doing a poor job but measuring COAL will never tell you that truthfully.
Trying to set your ammo to a consistent COAL is not the answer.

As for your sorted bullets. My advice as a non bullet sorter is dump em in a box, give it a good shake and forget about it. For now anyways.
No offense but you can't sort bullets without a comparator. My preference would be two comparators to sort bearing length only but thats just me.
Hope this helps.

 

[ColWhitecakes]

As for your sorted bullets. My advice as a non bullet sorter is dump em in a box, give it a good shake and forget about it. For now anyways.
No offense but you can't sort bullets without a comparator. My preference would be two comparators to sort bearing length only but thats just me.
Hope this helps.

Yeah, I'm starting to agree. Its just one of those things, I guess.
I'm still wonder, though; how do you consistently seat bullets to an exact location, as far as bearing surface or distance from the lands, if the die pushes from any other point besides from where the bearing surface length was measured? I still have the problem that I can set my die to the length of the dummy round I made by using the rifles action to seat the round, and the next bullet I seat will have a different COAL. It seems to me that even if you took two bullets that your comparator shows have the same bearing surface length, and seated them with the same settings on a die, your final results will have the distance of the bearing surface to the lands at different locations since the bullet is being pushed from a location other than where the two bullets are the same. Wouldn't it take a die whose plug was pushing the bullets from the bearing surface measuring point to seat them consistently?
I must admit to have only used Lee seating dies. Do any other ones work much differently?
Also, by two comparators, do you mean one on the boat tail and one on the ogive?

 

[jo191145]

You are absolutely correct that the seater plug sets the bullet on a different part of the ogive than where the comparator meets or the rifling for that matter.
Your also correct that getting that plug closer to that point will theoretically give more precise seating.
Nonetheless once you get a comparator you will "hopefully" find that the difference between the seating plug and rifling is pretty much spot on in a quality bullet.
Or to put it differently, the biggest variations in the ogive occur above the seater plug to the tip. In a decent bullet/decent seating die combo the variations normally seen between the plug and comparator are within .001".
Thats within the range of operater error in measuring using those types of tools.

If seating plugs seated from the rifling datum point there'd be too much damage to the bullet.

When you get right down to the nitty gritty all seating dies pretty much work the same.
Personally I'm not much of a fan of Lee dies but unless somethings manufactured out of tolerance they'll do just about a good a job as any.
I also should note I have very little expierience with Lee dies. A couple sets for vintage rifles I very seldom use.

Yes one comparator on the boattail and one on the ogive. That would sort bearing length.
Folks can argue all day about which matters most. Bearing length or ogive to base. I personally don't know
I'm not an expert on sorting bullets but to my knowledge sorting bullets has no exactingcorrelation to seating depth variations.
Its usually done to weed out bullets that were produced on different dies yet dumped into the same lot.
Obviously such different bullets may seat to different depths but usually the variations below that point exceed the seating depth issues. I think :-\
Most manufacterers try not to let that happen and some are more successful than others.

Bottom line, you need to stop moving the seater body to match the case mouth and you need to let the seater plug do its job. Once set neither should be moved.
Trying to make the COAL's consistent is just producing more inconsistent ammo than the die would make on its own.
A comparator is essential in judging whether your seater is doing it correctly.

 

[Leaddog]

I've read that Bryan Litz recommends sorting by base to ogive. There is enough variance at the boattail/pressure ring to skew your results. Not so much from the base of the bullet.

A few basic measuring tools are essential to loading consistent ammo.

 

[Steve Blair]

You are absolutely correct that the seater plug sets the bullet on a different part of the ogive than where the comparator meets or the rifling for that matter.
Your also correct that getting that plug closer to that point will theoretically give more precise seating.
Nonetheless once you get a comparator you will "hopefully" find that the difference between the seating plug and rifling is pretty much spot on in a quality bullet.
Or to put it differently, the biggest variations in the ogive occur above the seater plug to the tip. In a decent bullet/decent seating die combo the variations normally seen between the plug and comparator are within .001".
Thats within the range of operater error in measuring using those types of tools.

[br]
I use Bob Green's tool to sort bullets from leade contact to seating stem contact. The gauge is a .0001" unit. I am not sure what you mean by quality bullets but all that I have measured (Berger, Sierra, Lapua) vary by up to .011". In all three, the majority of bullets fall into three .001" groups, typical of a normal distribution about the mean. Since using the instrument, my bullet seating is within a .001" range. This has reduced group size and velocity spread but virtually eliminated unexplained flyers. [br]
The tool requires some practice to use consistently as the bullet is pushed against a 1½° angle. Once the proper feel is developed, sorting is reasonably quick. [br]
http://greensrifles.com/New_Products.html

 

[ColWhitecakes]

I use Bob Green's tool to sort bullets from leade contact to seating stem contact. The gauge is a .0001" unit. I am not sure what you mean by quality bullets but all that I have measured (Berger, Sierra, Lapua) vary by up to .011". In all three, the majority of bullets fall into three .001" groups, typical of a normal distribution about the mean. Since using the instrument, my bullet seating is within a .001" range. This has reduced group size and velocity spread but virtually eliminated unexplained flyers. [br]
The tool requires some practice to use consistently as the bullet is pushed against a 1½° angle. Once the proper feel is developed, sorting is reasonably quick. [br]
http://greensrifles.com/New_Products.html

I normally find the same spread range when measuring, as well as the majority falling within a certain area. I was pretty surprised to find the box of Amax's to be soconsistent, as the 75gr .224s I use in me and my son's .223s are normally not. I will give that tool a look.
Thanks

 

[BoydAllen]

Lacking fancy equipment, you can always use a caliper attachment, that contacts bullets at about the same place on the ogive as rifling marks appear, to check all your loaded rounds, to make sure that all rounds that are to be shot into a group, are in close agreement. Most of you should already have this capability.

 

[Steve Blair]

Lacking fancy equipment, you can always use a caliper attachment, that contacts bullets at about the same place on the ogive as rifling marks appear, to check all your loaded rounds, to make sure that all rounds that are to be shot into a group, are in close agreement. Most of you should already have this capability.

[br]
You must have the capability that Boyd mentions or it is not possible to know where the bullet is actually seated. I use the Sinclair comparator but others available probably work just as well.

 

[243winxb]

I place one of my cases in the shell holder, raise the ram to its full up position, and screw the die down just until it comes to rest very slightly snug against the case mouth. The die its self never touches the shell holder.

Try backing the die out a small amount. <(as already said) The Lee seating die taper crimps first then rolls so they say. What press are you using? Most have enough slop in the linkage to get as much as .005" variation on a single stage press. More on progressives. If your press has "cam over" make a shim for it, so the base of the seating die contacts the shell holder & cams over. Works with RCBS. Lee press has a stop, no cam over, i think??

 

[ColWhitecakes]

I place one of my cases in the shell holder, raise the ram to its full up position, and screw the die down just until it comes to rest very slightly snug against the case mouth. The die its self never touches the shell holder.

Try backing the die out a small amount. <(as already said) The Lee seating die taper crimps first then rolls so they say. What press are you using? Most have enough slop in the linkage to get as much as .005" variation on a single stage press. More on progressives. If your press has "cam over" make a shim for it, so the base of the seating die contacts the shell holder & cams over. Works with RCBS. Lee press has a stop, no cam over, i think??

I am using a Lee press. As far as I can tell, it doesn't cam over. I have been lowering the handle all the way down with the ram in its fully up position, then screwing the die in until the case makes contact at the top of the chamber area of the die. I think that this serves the same purpose as the washer as it is a positive stop. As I said previously, the shell holder never contacts the die (unlike my .223 die where it does before the case quite reaches the top). The case never actually press beyond that point, that is to say, never makes more than a firm contact at the top. When it does this, the case mouth seems to be positioned completely centered, at least to the naked eye, and can not wobble from side to side. I was kinda figuring this would be a plus, but maybe not. I will definitely give the washer a try, but I believe it may take an extra thick one in my case. As for crimping, I've never noticed any being effected on the case, and of course, I wouldn't want it to even if it is capable of it. All my brass is length sized with a Lee case length gauge as well. That is just what I have; but, it seems to make them all consistent.
Another one of my goals with sorting is to have all the bullets in a string of fire be as closely matched as possible for competition. If there is not at least 23 (2 sighters, 20 scores, and an extra "just in case" and maybe a few more) I dont use that group. Those become my practice rounds. It normally takes two full boxes of 75gr Amax in .224 to get enough to load at least the 140 for me and my son if I shoot .223 as well. This will be the first I have used the Amax in my .308.

 

[243winxb]

Lee Seating Dies.

Lee makes 2 seating dies for rifle. The standard has a crimp built into the die. The Dead Length Bullet Seating die does not. Different Die = Different adjustment. http://leeprecision.net/support/index.php?/Knowledgebase/List/Index/13/product-support

 

[amlevin]

Re: Lee Seating Dies.

Lee makes 2 seating dies for rifle. The standard has a crimp built into the die. The Dead Length Bullet Seating die does not. Different Die = Different adjustment. http://leeprecision.net/support/index.php?/Knowledgebase/List/Index/13/product-support

By using the washer, you are essentially creating a Dead Length Seating Die. The trick is to use a washer that's thick enough to take the crimping area of the die out of play but not be so thick as to cause one to lose seater adjustment.

By using this method I just finished and shot 50 .308 rounds that didn't vary more than .001" after seating.