Overall cartridge length

[Novashooter]

.015" variation is horrendous, you have a much more serious issue than only neck tension. It would be a waste to shoot those. Pull those rounds apart and try again.

The very first thing that popped into my head on the first post, and one of the most common issues people with this problem run into is a poorly fitting bullet seating plug. There's even a good chance you have a problem like sdupontjr describes where your plug is so out of wack you are seating by pushing on the bullet tip. It should be fairly obvious if you pull the plug out of your die and try it on your bullet. Ideally it should be making contact somewhere on the ogive of the nose. If it seems a loose fit you know it is bottomed out and hitting the nose. You can even color the bullet with sharpie to see where it is touching. I've done as sdupontjr said and used a slightly bigger drill bit to drill that out for nose tip clearance. I've heard of some people custom fitting seating plugs by filling them with epoxy and sticking a waxed bullet into them. Most brands you should be able to buy other seating plugs too. Even Lee you can send in a bullet and they will make a custom seating plug for you. I'm sure Redding will too.

No you should not be adjusting your seating die besides the very first round. There might be some variation that comes into play from your case, but the biggest factor will be a poor seating plug as stated. Outside of that the biggest variations will probably come from your dies and loading press. If you only measure COAL you will see quite a bit of variation because bullet tips vary quite a bit. If you measure CBTO you really shouldn't be seeing more than a plus or minus .001" variation. Maybe .002", but I wouldn't be too happy with that. It's usually so little your measuring technique is the biggest variable.

This is for sure a problem worth fixing.

 

[DiabeticKripple]

Make sure your seating plug is correct. It’s one the easiest things to do.

Pull it out and drop a bullet in it, the bullet should not move. If it can wobble around then you are seating off the tip of the bullet which can lead to more inconsistency

 

[allstajacket]

Thanks all,

My issue stemmed from the constantly adjusting the seating stem from round to round to try to get a consistent OAL without figuring in the inconsistencies in bullet length (especially with the soft lead tip.)

I did another batch, opened up the case mouth slightly with a chamfer tool, and after getting the initial OAL I then used the Hornady ogive tool and was able to get very consistent measurements.

New issue: bolt was slightly difficult to close. I struggled on this batch of brass getting a consistent trim with my RCBS manual trimmer, so I’m going to address that issue and work on trimming. For now, I’m going to use this batch for deer season (grouped very well, under 1”) and load up some more using new Lapua brass. Shouldn’t need to worry about trimming any brass for a bit.


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[SloppyJ]

Ogive measurement is the one that really matters anyway assuming you have the length in the mag to have that variance. That's what I would focus on. I've chased this too and came to the conclusion that there is quite a bit of variation in bullet manufacturing. I see it more with any sort tipped bullet. I discovered it when playing around with the Quickload software and inputting the actual bullet information compared to the stock settings in the software.

I'm most concerned about the seating depth comparing the ogive of the bullet to the lands of my rifle so that's what I measure. The only round I go off of COAL is my 30-30 where I don't need to to be gnat's ass.

Take that with a grain of salt, I've only been reloading around a year but that's what made sense to me.

 

[SloppyJ]

Thanks all,

My issue stemmed from the constantly adjusting the seating stem from round to round to try to get a consistent OAL without figuring in the inconsistencies in bullet length (especially with the soft lead tip.)

I did another batch, opened up the case mouth slightly with a chamfer tool, and after getting the initial OAL I then used the Hornady ogive tool and was able to get very consistent measurements.

New issue: bolt was slightly difficult to close. I struggled on this batch of brass getting a consistent trim with my RCBS manual trimmer, so I’m going to address that issue and work on trimming. For now, I’m going to use this batch for deer season (grouped very well, under 1”) and load up some more using new Lapua brass. Shouldn’t need to worry about trimming any brass for a bit.


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Your cases may be long but if you're pushing the upper max of the load you might back off a bit. A sticky bolt is a pressure sign. Chamber an empty case and see if you still have the difficulty.

 

[allstajacket]

Your cases may be long but if you're pushing the upper max of the load you might back off a bit. A sticky bolt is a pressure sign. Chamber an empty case and see if you still have the difficulty.

Some of the rounds chambered just fine, it was just a bit difficult to close the bolt (some slight resistance) on a few of them. 44.0 grains of IMR4064 so while it is approaching max, it definitely isn’t at it. I also saw no indication of pressure when looking at the primers.


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[SloppyJ]

Some of the rounds chambered just fine, it was just a bit difficult to close the bolt (some slight resistance) on a few of them. 44.0 grains of IMR4064 so while it is approaching max, it definitely isn’t at it. I also saw no indication of pressure when looking at the primers.


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Apologies, I read that wrong. You were talking bolt close, not open.

 

[Rich M]

I had bought some Nosler 2nds and was experiencing the same. Switched to Sierra Pro Hunters and had much more consistency w the overall length. In that instance, it was the bullet.

The way i fixed the problem was to stop worrying about it - I set the length and load up what i'm there to load up. Then go shoot.

 

[allstajacket]

Apologies, I read that wrong. You were talking bolt close, not open.

No worries, appreciate the input. I’m going to reassess my sizing die setup, and go from there. Not sure how much loading I’ll do over the remainder of the year but I’ll try to report back with the results!


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[Novashooter]

Some of the rounds chambered just fine, it was just a bit difficult to close the bolt (some slight resistance) on a few of them. 44.0 grains of IMR4064 so while it is approaching max, it definitely isn’t at it. I also saw no indication of pressure when looking at the primers.


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This is almost never the case length. Most standard rifles could handle a case .020" longer than listed maximum, although it may not be a smart thing to do. More than likely you have some cases with too little shoulder bump during resizing.

 

[sdupontjr]

Some of the rounds chambered just fine, it was just a bit difficult to close the bolt (some slight resistance) on a few of them. 44.0 grains of IMR4064 so while it is approaching max, it definitely isn’t at it. I also saw no indication of pressure when looking at the primers.


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If you are having problems chambering a round it could be a couple things.

1) the brass isn't fully resized.
2) brass isn't trimmed to spec. or is range brass from another rifle that has a bigger chamber than yours, but reverting back to (1) should fix that when trimmed to length.
3) if your seating bullet die isn't set correctly. I have an RCBS FL die set for my 308. Somehow it got set way off, don't know how or what. But when the bullet was seated, it was also trying to add a crimp. But in the process of that, I noticed my rounds wouldn't chamber. It was off so much that the body / shoulder junction had a buldge in it. Not much but the OD of the case right at the body / shoulder junction would hit, not allowing the round to chamber or was hard to chamber.

I ended up having to pull all bullets and powder, remove the de-capping pin out of my FL die, resize the brass back to normal and that's when I found my seating die was messed up. My set screw had come loose on my die lock nut. I have the hornady lock n load quick connectors and have worked flawless since day one with plenty reloads. Must have come loose when I installed it into the press.

edit:
I also had colored the entire round with a sharpie, bullet and all, let it dry and chambered it. Thats how I noticed the slightly raised body / shoulder junction.

 

[jjohnsonElknewbie]

If the OP is using new brass, I wouldn't expect to see a ton of variation case-to-case, but I've never used virgin brass so I could be wrong. That being said, in recent experience, I've observed some interesting variation that was making my head spin as a newb reloader.

I finally got my Frankford Arsenal case trim and prep center a few weeks ago. Prior to this, I ran around 200 once-fired .30-06 cases through my Redding FL .25-06 sizing die. After re-sizing, some of the cases were too long to chamber without difficulty in my rifle (Tikka T3x). The vast majority of these were 2.501-2.510 (SAAMI max OAL is 2.494) after sizing. After setting up the trimmer and trimming all of the cases, I found they fell into 3 different OAL "buckets".

2.487-2.489
2.490-2.492
2.493-2.494

Anything that was over 2.494 (max SAAMI case length) I adjusted the trimmer and ran through again to get into spec. There were 4 pieces of brass out of the whole pile that actually trimmed beyond factory min. (2.484) at the same trimmer setting (they trimmed to 2.477). I tried to FL size these again to lengthen to no avail. To be safe I tossed these "shorties".

These were all random pieces of R-P brass my buddy and brother gave me from at least 2 different .30-06 rifles. The trimmer operates off the shoulder, so the variation in case neck for these was interesting. I'm wondering if the case necks will normalize after being fire formed in my rifle chanmber.

My plan when seating bullets for these is to start with the longest cases to set the seating die. I need to be 3.216 or less to be off the lands in this rifle. My thought is that once I get to 3.216 with the longest cases, I should naturally be a hair less COAL for the shorter cases.

 

[TaperPin]

The question of how much of a difference changes in seating depth really makes definitely depends on the individual rifle and load, but this is an example where being within .005” wouldn’t change group size a lot.

At about 3:45 this guy has the results of a bullet seating depth ladder test, duplicated over a couple of of days.

 

[Novashooter]

The question of how much of a difference changes in seating depth really makes definitely depends on the individual rifle and load, but this is an example where being within .005” wouldn’t change group size a lot.

At about 3:45 this guy has the results of a bullet seating depth ladder test, duplicated over a couple of of days.

Oh man, if that's how that guy is testing loads, he is drawing a LOT of false positive conclusions.

 

[TaperPin]

Oh man, if that's how that guy is testing loads, he is drawing a LOT of false positive conclusions.

In what way?

 

[Novashooter]

In what way?

All he did was 3 shots per seating depth. May has well have done 1 shot each. Complete waste of his time.

 

[Vern400]

I ended up loading up a new batch, and once I got the overall length I started only using the cartridge base to ogive measurement. Ended up with a batch of 20 with a deviation of only 3-5 thousandths.

Might pull the previous batch. Only 20 rounds thankfully. I had another issue where the case mouth was a bit too tight, so I had a small amount of of the bullet jacket being sliced off when seating.

So I’ll pull those, toss the projectiles, and use a hand reamer to open the case mouth a touch to make it easier to seat.


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Bad ID chamfers on case mouth causes uneven bullet alignment, meaning bullet run out, inconsistent neck tension, and can shave copper off the bullet. That obviously causes a bump on the bullet that has to be crammed down the bore. This is one of the most important Case prep operations and it has a huge impact on precision / group sizes.

This isn't really my opinion. It's pretty much a consensus among handloaders that are shooting groups.

 

[TaperPin]

All he did was 3 shots per seating depth. May has well have done 1 shot each. Complete waste of his time.

I like three shot groups to exclude loads from further consideration - more shots will never shrink a group.

There‘s nothing wrong with larger group sizes to include a best load - it’s just a different way to arrive at an acceptable level, and it requires a lot more expense, time and barrel wear.

A rifle shooting 1/4 moa with large groups opening to 1/2 moa is a nice problem for him to have.

 

[Novashooter]

I like three shot groups to exclude loads from further consideration - more shots will never shrink a group.

There‘s nothing wrong with larger group sizes to include a best load - it’s just a different way to arrive at an acceptable level, and it requires a lot more expense, time and barrel wear.

A rifle shooting 1/4 moa with large groups opening to 1/2 moa is a nice problem for him to have.

3 shot groups might be ok... if you shot 8-10 groups per variable.

Not doing that isnt a "different way", it's choosing to ignore statistics.

 

[TaperPin]

3 shot groups might be ok... if you shot 8-10 groups per variable.

Not doing that isnt a "different way", it's choosing to ignore statistics.

For hunting rifles I’d say the misapplication of statistics hurts more than it helps the reloader. You can call it ignoring statistics, but it’s only ignoring the statistics that don’t make a difference. Standard deviation is a useful statistic of velocity. 95% confidence intervals on group size not so much.

Shooting 200 rounds to develop a load would use up around 1/10th of a barrel’s life, and the throat would be measurably deeper. It’s not shooting the same velocity and the absolute most accurate load has changed. Every trip to the range also has different shooting conditions. Every day a shooter has ups or downs. Higher or lower chamber heat and the amount of cartridge soak effects pressure and velocity. Trying to force a high level of confidence into one point in time ignores the changing conditions.

I’ve purchased two rifles in the same caliber - it doesn’t take a full box of cartridges to tell which one is more accurate - two 30 shots groups might confirm what is pretty obvious, but it’s not a better solution. It’s a more expensive solution for the same outcome. Many decisions in reloading are very similar - we get to a good load by eliminating bad loads.