Variations in seating depth

Gater

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Aug 19, 2019
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New to reloading! After doing all the prep work and I go to seat my bullets they keep varying. I have a Forester press and a Forester micrometer seater die. All the brass is Lapua all sized the same. Have a Lee neck die with .002 tension. Trimmed all the brass to the same length. Using Hornady ELD-X bullets., Am trying to get a OAL of 2.466 which puts me .025 off the lands. When I go to seat my bullets one will be correct at 2.466 next one will be 2.471 then maybe 2.473 then 2.468 then maybe another correct one. Is this normal or am I doing something wrong? I can’t believe I have to adjust the die every time? Any help would be appreciated thanks
Call Forster mine did the same sent it in they cleaned and replaced the seating rod no charge now works great. Don’t know it was bent because I do not compress loads and I team necks inside and out but that’s what I was told was the problem. Good luck
 

ajkellerusmc

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The most significant factor that actually causes inconsistent CBTO measurement (IMO) is COMPRESSED loads. Compressing powder to any degree will frequently result in OALs that vary.

Just thought I'd mention it in case you had a case full of powder. :>)
I have experienced this with the 6.5PRC, H1000 and 131gr Hammers by as much as .025". You read that correct .025" I have to keep cycling the round several times to get them even close but they are also at .003" tension.
 

COBrad

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I’m loading 55.3 grains of H4831sc and 160 Accubonds in a .284. They are compressed. I have found that lightly tapping the charged case a half dozen times on the bench packs the powder a little, I use a slow consistent stroke and turn the case after the initial stroke a time or two. This make my cbto within a thou or two. Works for this rifle. I have also found using my VLD stem helps. I have a 22-250 shooting heavy VLD’s at long range. I seat the bullets in three steps, rotating the case a third turn each time. This give me cbto that is + or - .0005 and very little run-out. Redding comp dies on everything.
 

Nuclear Worker

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How much neck tension do you have? What are the fired, resized and bullet seated neck diameters? My biggest break in consistent seating depth came when I went to .002 neck tension, brushed the inside of necks, and use dry lube on the inside of the necks.....now I'm worried if my bto varies by .0015....
I have.002 neck tension also brushed the inside of necks. No dry lube. I am running 58.2 gr. Of Retumbo powder maybe be the powder is pushing the bullet back up? Have a Lee die that they made for me when I sent them 2 fired cases and made a -002 mandrel for neck resizing. My seater die is a Forester micro die.
 

Nuclear Worker

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I’m loading 55.3 grains of H4831sc and 160 Accubonds in a .284. They are compressed. I have found that lightly tapping the charged case a half dozen times on the bench packs the powder a little, I use a slow consistent stroke and turn the case after the initial stroke a time or two. This make my cbto within a thou or two. Works for this rifle. I have also found using my VLD stem helps. I have a 22-250 shooting heavy VLD’s at long range. I seat the bullets in three steps, rotating the case a third turn each time. This give me cbto that is + or - .0005 and very little run-out. Redding comp dies on everything.
Thanks that was my thought also. I have heard people use a electric toothbrush against the case to compact the powder. Thought maybe try the wife’s bedroom toy but that probably vibrates to much😂
 

Nuclear Worker

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Your seater stem seats off the ojive. You're probably measuring the OAL from cartridge base to bullet tip. If so, you will almost always see a variation. Measure your completed cartridge from the cartridge base to the ojive using a bullet comparator. My guess is that your ammo is much more consistent in the measurement that counts.

Measuring off the bullet tip is only useful to determine cartridge length VS magazine length.
I am using a comparator
 

Varmint Hunter

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I am using a comparator

In that case I would think that load compression or excessive neck tension are two areas worthy of review.

Here's one for laughs: my 2.5 year old grandson likes to help me load ammo; no different than his mother before him. My grandson likes to tap the press arm several times at the bottom of the stroke when bullets are being seated. This silly practice lead to me recheck the CBTO measurement on "his" ammo. Interestingly enough, I found it to have slightly improved consistently. Admittedly, this was a very small sample but its worthy of some further exploration.
 

Nuclear Worker

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In that case I would think that load compression or excessive neck tension are two areas worthy of review.

Here's one for laughs: my 2.5 year old grandson likes to help me load ammo; no different than his mother before him. My grandson likes to tap the press arm several times at the bottom of the stroke when bullets are being seated. This silly practice lead to me recheck the CBTO measurement on "his" ammo. Interestingly enough, I found it to have slightly improved consistently. Admittedly, this was a very small sample but its worthy of some further exploration.
I think I have found the problem. First I took a Wilson cartridge case gage and made sure all my cases were cut the same. They were, then I went through the process of setting up my die again after I cleaned with brake cleaner. While doing that I found the shell holder plate loose in my press! I put together 5 empty rounds to check consistency. All measured 2.466-2.467. Now will load with powder and see what I get. Will let you know. Thanks for everyone’s help.
 

LoneTraveler

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Feb 7, 2014
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You may want to consider buying a MTM funnel set with the long powder drop tube to settle powder in case. Or vibrating the case after the powder is dropped, To settle powder enough to allow space for bullet.

Trying to seat bullets on powder without enough space can become feudalistic, COAL will keep changing. Unless you are load bullets with canular grove and crimp them in tight.
 

Nuclear Worker

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You may want to consider buying a MTM funnel set with the long powder drop tube to settle powder in case. Or vibrating the case after the powder is dropped, To settle powder enough to allow space for bullet.

Trying to seat bullets on powder without enough space can become feudalistic, COAL will keep changing. Unless you are load bullets with canular grove and crimp them in tight.
I do have a long funnel drop. As I posted I think I found the problem.
 

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