Case Trimming

Moderators: gds, bakerjw, renegade, bamachem

Post Reply
randymessman
New Member
Posts: 7
Joined: Tue Oct 02, 2012 5:44 pm

Case Trimming

Post by randymessman »

So I went out and got the HF Chop Saw, got my 300 BLK dies in and just bought a hornady trimmer. Finally got the trimmer dialed in and my cases are consistently 1.367 or so.

However, some of my first cases were in the 1.35 range. Does anyone know what the minimum case length would be for safe reloading?

In the Lyman guide it talks about trimming the cases down and ensuring that they don't exceed a specific length, but it doesn't say much about how far below the trim length is ok.

I'm new to reloading and would really appreciate the help.

Thanks!
rjacobs
Silent But Deadly
Posts: 1145
Joined: Tue Jul 31, 2012 4:27 pm
Location: Dallas, TX

Re: Case Trimming

Post by rjacobs »

1.368 +0.000 -0.020

I trim to 1.358 as well as a lot of people I think. Gives you a few reloadings worth of growing before you need to trim again.
300BLKOut Brass
[email protected]
www.300blkoutbrass.com
randymessman
New Member
Posts: 7
Joined: Tue Oct 02, 2012 5:44 pm

Re: Case Trimming

Post by randymessman »

Thanks!
User avatar
yondering
Silent But Deadly
Posts: 711
Joined: Thu Aug 02, 2007 12:22 pm
Location: NW Wa. state

Re: Case Trimming

Post by yondering »

randymessman wrote:However, some of my first cases were in the 1.35 range. Does anyone know what the minimum case length would be for safe reloading?
There is no "minimum safe length", per se. As long as the case has some neck, and can hold a bullet, it will be "safe"; the case headspaces on the shoulder, like most bottleneck rifle cartridges, so there is no safety concern with a short case. It can affect accuracy and maybe reliability though if a case is drastically too short.

However, you want to keep the neck as long as possible, within reason, so most load manuals specify the trim length as .010" less than maximum case length.
User avatar
hotbrass
Silent Operator
Posts: 59
Joined: Sun Feb 03, 2008 1:24 am

Re: Case Trimming

Post by hotbrass »

You want to keep plenty of neck tension on the bullet if you are using an AR to keep the bullet from being pushed back when cycling. The more neck length to the max the better. And you can crimp the neck if you want.
rjacobs
Silent But Deadly
Posts: 1145
Joined: Tue Jul 31, 2012 4:27 pm
Location: Dallas, TX

Re: Case Trimming

Post by rjacobs »

yondering wrote:
There is no "minimum safe length", per se.
Im sorry you're wrong. AAC(and SAAMI) specs the case length to be 1.368 +0.000 -0.020 so I would say there IS a minimum case length. Now the reason for the min length, I can only assume is to provide adequate neck tension(as hotbrass stated), maybe RSilvers can explain why they chose that particular number.
300BLKOut Brass
[email protected]
www.300blkoutbrass.com
User avatar
hotbrass
Silent Operator
Posts: 59
Joined: Sun Feb 03, 2008 1:24 am

Re: Case Trimming

Post by hotbrass »

Probably old rule of thumb, bottle neck cases neck length close as possible to bullet diameter.

But shortened to fit in AR-15 mag.

I have no idea. :oops:
User avatar
yondering
Silent But Deadly
Posts: 711
Joined: Thu Aug 02, 2007 12:22 pm
Location: NW Wa. state

Re: Case Trimming

Post by yondering »

rjacobs wrote:
yondering wrote:
There is no "minimum safe length", per se.
Im sorry you're wrong. AAC(and SAAMI) specs the case length to be 1.368 +0.000 -0.020 so I would say there IS a minimum case length. Now the reason for the min length, I can only assume is to provide adequate neck tension(as hotbrass stated), maybe RSilvers can explain why they chose that particular number.
Read my post again. I said there is no minimum safe length, which is what the OP asked. I also mentioned the minimum optimal length, but evidently you ignored that. If you really don't understand the reason, please don't try to start an argument about it. :roll:
rjacobs
Silent But Deadly
Posts: 1145
Joined: Tue Jul 31, 2012 4:27 pm
Location: Dallas, TX

Re: Case Trimming

Post by rjacobs »

yondering wrote:
rjacobs wrote:
yondering wrote:
There is no "minimum safe length", per se.
Im sorry you're wrong. AAC(and SAAMI) specs the case length to be 1.368 +0.000 -0.020 so I would say there IS a minimum case length. Now the reason for the min length, I can only assume is to provide adequate neck tension(as hotbrass stated), maybe RSilvers can explain why they chose that particular number.
Read my post again. I said there is no minimum safe length, which is what the OP asked. I also mentioned the minimum optimal length, but evidently you ignored that. If you really don't understand the reason, please don't try to start an argument about it. :roll:
So i guess it's ok to ignore the min case length spec per aac and saami? That is what i get from your "argument".

I understand the case headspaces off the shoulder and beyond that isn't all that important, but a spec is listed so that is what you should trim inside of. To tell people otherwise is just ridiculous. If you want to trim shorter, go for it, it's your potential kaboom, i personally will not and i would never give somebody the advice to do it either.
300BLKOut Brass
[email protected]
www.300blkoutbrass.com
randymessman
New Member
Posts: 7
Joined: Tue Oct 02, 2012 5:44 pm

Re: Case Trimming

Post by randymessman »

Thanks for all the input. Loaded up 50 VMAX 110 grain's. Had 2 FTF. Both of them I had to really pull hard on the charging handle to get them out.

Cleaned and started to resize and deprime the cases and got a case stuck in die. got it out finally but had to remove decapper and tap it with a hammer to get the shell out. Mushroomed the end of the decapper a little bit. Decapper won't fit back in decapper lock nut. Tried filing the end of the decapper to get it back into the decapper locking nut...

Hung it up for the day.

I'm going to order a new 3 dollar decapper from Lee.
Post Reply

Who is online

Users browsing this forum: Google [Bot] and 50 guests