ADG brass shorter then recommended length

HANGum HIGH

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Hey all,

New to reloading and have a question. I have a 7 saum with the case length recommended at 2.035. I measured only a few of them before I reloaded them and they were fine. I am now ready to deprime and clean the fired brass and finding out the many if not most of them are measuring at 2.028-2.025. When I resize them, will that help getting them to 2.035? Will 2.025 be ok if I trimmed them all to that length? Not sure my next step. Any help would be awesome!!!
 

whatnext

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Yes, you will be fine with your suggested process. However, you may want to trim all to the same length after the second firing/resize cycle to get a very slightly longer neck if that is important to you. However, 10-20 thou' shorter than SAAMI recommended trim length will pose no issues with the chamber.
Except the possibility of a carbon ring developing behind where a SAAMI case mouth should sit and the next time a SAAMI case is loaded he gets a pressure spike.
 

Rardoin

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Except the possibility of a carbon ring developing behind where a SAAMI case mouth should sit and the next time a SAAMI case is loaded he gets a pressure spike.
If you are trimming the necks close enough to true chamber length to prevent a carbon buildup (and that would be the only way to prevent it) you would have a greater risk of the neck impinging on the end of the chamber and causing a pressure spike. A regularly and properly cleaned chamber will prevent problematic carbon buildup in my experience.
 

whatnext

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If you are trimming the necks close enough to true chamber length to prevent a carbon buildup (and that would be the only way to prevent it) you would have a greater risk of the neck impinging on the end of the chamber and causing a pressure spike. A regularly and properly cleaned chamber will prevent problematic carbon buildup in my experience.
But .010-.020” shorter brass is just that. Shorter than true chamber length. I agree with you on keeping the chamber clean but how many threads have you read on here about removing carbon rings. It happens.
 

Mikecr

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The tighter you are to chamber end, the lower the chances of a carbon ring ever forming, and the lower the potential ES.
Given this, I don't trim until brass has reached stable dimensions (~3rd FFng) and well within 10thou of chamber end.
If it never reaches or settles there, I don't trim.

I like fired necks having nearly zero carbon sooting. Only a bit at case mouths.
That's when I know necks are sealing quickly and consistently as they should.
This has provided a better return for me than same but excessive trim lengths.
 

MagnumManiac

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There is no need to trim cases until the max length is exceeded anyway.
If you buy a chamber length gauge, you can keep your case growth to near chamber end, as Mikecr point as out above.
Have been doing this on my comp rifles for a long time, never had a carbon ring.

Cheers.
 

jgs8163

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2.035” is max lemgth. 2.025 is trim to length. Ref. Hornady 10th edition. But definitely re-size before you trim.
^^^^^ this!
you don’t want to start at max length you want to be under as the brass will grow after the first firing. Resize all the brass before you load any of it then check length and trim all to same spec you choose. Then VLD chamfer case necks in and out. New brass in my opinion should be worked over and made as uniform as possible. I like to do it before firing but I know some others that prefer to work it after first firing. Good luck!
 

MagnumManiac

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I never trim until at least 3 SIZINGS. It is sizing the brass that makes it grow longer.
As L.Sherm points out, brass of all makes grows at different rates until it stabilises.
Also, it makes a difference how much brass you are moving when sizing. With honed neck Forster dies and modified expanders that only move the neck diameter .0015” while sizing then using a mandrel for final IR fit, the neck grows very little. A standard die will elongate the brass .005” or more.
A bushing die may move the brass .005”-.006” and the brass will still grow longer, yet at a slower rate generally.
Also note, that fast sizing will also increase the amount the brass grows…slow and hovering at the top of the stroke can almost eliminate brass growth once the brass is stable.

Cheers.
 
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