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pyscodog

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Loading 75 grain Vmax for my 243. I set my die to the length I wanted. Then loaded 30 rounds. After getting done, I randomly picked out a few loaded rounds and there's as much as .005 difference. Some shorter,some longer. I know this doesn't sound like a lot but my desired length is kissing the lands so these rounds that are long are going to have a slight jam. Aside from buying precision dies, is there a solution to this?
 
COAL and off the ogive both. Measuring from the ogive, I get some as much as .004 short to .002-.003 long. Thats a lot of difference and upper end loads can cause excessive pressure. I had plans on running this rifle on the hot side with lighter bullets. I'm just trying to get consistent lengths and I'm hoping during load work that the OAL will be shorter as I really don't like a bullet jammed or kissing the lands. But...you have to start somewhere.
 
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Could your bullet point be bottoming out in the seating stem? As you know, bullet OAL can vary considerably. If bullet bottoms out in seater stem, COAL would vary an equal amount as the OAL.??

Regards,
hm
 
How consistent do the bullet lengths themselves measure? Varmint bullets are not terribly consistent and variations in length and ogive will effect COAL after seating. If you have variation in bullet lengths, then you can't seat batches to "kiss" the lands because each bullet is a different length. You'd have to seat each bullet to the desired depth. With varmint bullets, you may be better off fully committing to jammed or jumping, because you don't want some to jam while others jump. Go all in, one way or the other. Frankly, you're probably better off jumping.

Other considerations that effect COAL: compressed loads, inconsistent neck tension, neck lube, die quality, seating stem shape, seating technique.
 
I am a little concerned about neck tension. It feels like some do seat easier than others. These cases have been loaded quite a few times but the primer pockets are still nice and tight so I still use them. May not be a great idea but I have a lot of it.
 
I only had 4 bullets left in the box. Shortest was 1.477 and the longest was 1.483, off the ogive. May have just figured out the problem.
 
Anneal with a socket chucked in a cordless drill, and a $10 propane torch. Super easy, rotate the case and stop after 5-8 seconds just as the case mouth starts to turn red. Air cool. You don't need a fancy machine. Seating will all feel exactly the same after that. Try it.
 
How are you measuring them? If your going to the tips there is some differences just in bullet length. Any differences in neck tension will give you differences in length. Slop in your press will do the same. Having a seater plug deadicated to that bullet will help back when we would fill the seater stem with hot sealing wax and press the bullet nose into it to give full contact. Annealing you case necks will help with the neck tension. I use a drill, deep socket and dump them out on a wet towel to suck the heat out of them before it migrates to the case head that way is better than dropping in water as you don't need to dry the cases.

Seating dies are steel on steel once you have the seating did loçked down there isn't anything that can change. The only variable is the bullet not fitting the seating stem , some çompanies have custom seating stems for special bullets.
 
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Originally Posted By: pyscodogI only had 4 bullets left in the box. Shortest was 1.477 and the longest was 1.483, off the ogive. May have just figured out the problem.

do you have another box you can check if they're more consistent?

also - have you tried contacting hornady with that info? i wonder if thats within their acceptable tolerance range for ogive measurements for that product.
 
No more bullets to check but I can get more easy enough. Just a trip to the store tomorrow. I am really hoping with the loads I have now that something is worthy of more load work and seating depth as I really don't like shooting bullets that close to the lands. I like a little jump. I have a bunch of different brands and weights in 6mm so if the V-Max doesn't work, I have options on the shelf.
 
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