Varying neck thickness could cause inconsistent neck tension which will affect set depth especially when bumping the powder with bullet base.
Seating depth inconsistency
- Thread starter Asumner
- Start date
wkdickinson
Gold $$ Contributor
Inconsistent ogive form. Bullet seating stem contacts bullet way further forward than a bullet competitor. I bet if you made a comparator insert the same size as your seating stem, you would find your loaded rounds are very consistant. Ask me how I know .
L.Sherm
Silver $$ Contributor
This is why I use Whidden Comparator that takes bushings for bullet dia. I go .003 smaller than bullet, your measuring more off the ogive then.
dellet
Gold $$ Contributor
Are you able to “feel more compressed”. Vs feel more resistance seating the bullet?
Neck problem vs compressing powder.
With a fired case, or better sized if you can expand the neck, dump your powder charge your regular way, then insert a bullet and let it sit on the powder them measure your length. That will let you know exactly if and how far you’re compressing the powder. If you do it a few times with the same case and have variations in measurement, you’ve found the problem.
A drop tube helps, not really needed unless the neck on your powder funnel is real small. The big difference is pouring very slow instead of a dump. Hold the funnel and drop right down the tube of the funnel from about 6” above tap the case a couple times. Again use the case where you can insert the bullet and compare both your normal and high drop methods. You should see a significant difference in powder level.
Neck problem vs compressing powder.
With a fired case, or better sized if you can expand the neck, dump your powder charge your regular way, then insert a bullet and let it sit on the powder them measure your length. That will let you know exactly if and how far you’re compressing the powder. If you do it a few times with the same case and have variations in measurement, you’ve found the problem.
A drop tube helps, not really needed unless the neck on your powder funnel is real small. The big difference is pouring very slow instead of a dump. Hold the funnel and drop right down the tube of the funnel from about 6” above tap the case a couple times. Again use the case where you can insert the bullet and compare both your normal and high drop methods. You should see a significant difference in powder level.
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ELR LVR
Silver $$ Contributor
Good point,
A guy could run a drill bit into the stem to enlarge the opening to be closer to the comparator hole dia.
this will help with consistency
(of course guys with lathes can do this kind of thing a little easier)
So I definitely feel the difference as I hit the powder, some have no crunch feel and some it feels like I hit a wall with crunch. When I check the seating depth with my SAC comparator I see a length difference. I can obviously push it down still by using my mic but I then figure I am adding more compression. The biggest one data string I have done has a 9.4 sd overall but still the pressure is different and I have seen random spikes in velocity in shorter strings. I am wondering with a compressed load would it cause a vertical string and keep my horizontal at a minimum because I achieved the same seat depth just not after one pull of my co-ax. The is me just speculating I am a super novice at reloading but I do like the analytics of the data. I always try and take everything but human error out of the equation that I can. I shoot a lot but not at the level a lot of you have been for years so I am just trying to be a sponge while also asking questions. The drop tube and slow rate of drop makes a lot of sense to me. I definitely do not drop slow at all and that could make a huge difference for me that I hope to try tonight. I seem to read and watch a lot of things where the seating depth never changes and when mine does I know there has to be an issue that I am doing. My seating stem is the A-tip one from Hornady in that seater and my le Wilson seater has the stock one for the arc. If this helps. This is also a bolt gun and not a gas gun.
I need a new lathe lol. A big regret for me was selling it.
Every time I've ever shot compressed loads, I have seating depth variances. My solution: Use powder that doesn't require compression. There are lots of powders that work fine, if the one you're using doesn't.
dellet
Gold $$ Contributor
If your SD is single digits, it’s not terrible, if it’s repeatable and consistent.
Vertical string without horizontal can be a lot of things.
Most important thing is only chase your tail in one direction at a time.
It’s been pointed out that unless you are sorting your bullets buy base to ogive and possibly overall length, you won’t know what to expect measuring them loaded. It’s a good data point.
Compressed loads are no big deal, but mixing compressed loads with no or different amounts of compression can get frustrating. And it varies with powder choice. Case capacity, speed of pour, speed of seating the bullet, how long you wait before lowering the ram all come into play. You just need to be very consistent with everything. It all effects ignition.
The other thing to check is that compressed loads don’t always stay that way. Seat a bullet tonight, check length in a couple hours, then again tomorrow night. If the length has grown, you either need less compression, or more crimp.
One other thing that might surprise you is that the same powder charge, same seated depth, no compression, may actually be higher velocity than the compressed load. It can go either way.
Vertical string without horizontal can be a lot of things.
Most important thing is only chase your tail in one direction at a time.
It’s been pointed out that unless you are sorting your bullets buy base to ogive and possibly overall length, you won’t know what to expect measuring them loaded. It’s a good data point.
Compressed loads are no big deal, but mixing compressed loads with no or different amounts of compression can get frustrating. And it varies with powder choice. Case capacity, speed of pour, speed of seating the bullet, how long you wait before lowering the ram all come into play. You just need to be very consistent with everything. It all effects ignition.
The other thing to check is that compressed loads don’t always stay that way. Seat a bullet tonight, check length in a couple hours, then again tomorrow night. If the length has grown, you either need less compression, or more crimp.
One other thing that might surprise you is that the same powder charge, same seated depth, no compression, may actually be higher velocity than the compressed load. It can go either way.
Ok well crap lol, I will check this for sure. I know that I can measure all of my bullets that I have left in this lot and just see. I will also pour slower and check that. I will also separate rounds that I had to fix to get the proper seating depth from ones that just work. I do have a question though. Say a bullet starts to change due to compression meaning it’s slowly working its way out. Should I discard that piece of brass. The one thing I do know is that all of my brass came from factory ammo so probably I have at least a chance that I am working with 5 different lots of brass over my 100 rounds I am cycling through. Also they are in 50 round boxes now so I have no clue other than firings which are which. I don’t know if it matters now that they have all been fired through my rifle 4 times so it may take that statistic out now idk.
Also the last 50 rounds have been using this load in 20 or 10 round strings and they all came out in the 9s as far as sd
This! And some folks on here report using an electric toothbrush touched to the brass to settle the powder.
dellet
Gold $$ Contributor
If bullets are pushing out, it could be from a couple reasons. Loose necks, or just too much compression.
You can fix too much compression a couple ways. Possibly just Change your pour, lesson the charge or not seat the bullet so deep. That’s provided the problem isn’t simply how fast you’re trying to ram the bullet into the powder.
Go get a bucket of sand, put the tip of your finger on the sand and slowly push it in. Then pull your arm back about a foot and as fast and hard as you can punch the sand with your finger.
I wouldn’t throw any brass away unless it’s been annealed and you’re still having problems.
There’s a ton of variables that you can’t even start to sort through until you have bullets that are the same length, and your process of putting them in the case, including pouring the powder, is consistent.
Start with the basics.
Sounds like a plan. Hopefully I can do this tonight or so. Hopefully I’ll be able to shoot at distance this weekend at least 600 or so to see if things hold out. The furthest I have taken this current load is 200 at my house but that’s all I got. At the range I will have a bench as well and not the back of my truck, no excuses though.
Yup. This is why I now sort my bullets using a comparator insert that makes contact at the same place on the ogive as my seating stem. It give me very consistent seating depths . . . though when measuring seating depth after wards with a standard comparator insert, the difference between the two contact points shows up (not a whole lot, but it's there)
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In my limited experience, I do find it's not unusual that there can be .005 - .006" difference in bullet BTO's when I sort through boxes of 500. The difference can be even greater between lots of bullets.
I just measured around 20 and I had to main measurements but they were 5 thou different. This is insane to me. This means my seating depths when I try to make them all the same can vary a minimum of 5 thou
ELR LVR
Silver $$ Contributor
gonna have to chuck 'em in a drill and sand the ogives down until they're all the same
finish up with steel wool
dellet
Gold $$ Contributor
Enough to mean the difference between compacting the powder and crushing it if you’re on the edge.
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