6.5 Creedmoor resizing question

[Sgtsideways]

I see many of you are setting the shoulders back about 0.002". My fired cases (1-3x) of Hornady, and Federal 6.5 are showing shoulders measuring 1.559 to 1.560" to the shoulders. These will still chamber with no problems and using a Wilson case gauge, there appears to be little brass movement ( no trimming required). Seems really strange to me, so I thought I'd ask for opinions.
Do I still need to set shoulders back? I resize with a Redding FL S type die and am using close to max. charges for loads with no pressure signs. Rifle is MRAD.
Pretty new to c.f. reloading and I always read that it would be difficult to chamber reloads that don't have the shoulders set back. Doesn't appear to be that way for me, but I might be setting the shoulders back when I chamber the round?

 

[Newbie2020]

If FL case sizing I guess I don’t know why there’s still a need for bumping shoulders

 

[Sgtsideways]

If FL case sizing I guess I don’t know why there’s still a need for bumping shoulders

Hi,
What I did was to resize the necks and body, w/o bumping the shoulders.

 

[AllenOne1]

If you are not having any issues chambering a round I would assume you have enough shoulder clearance for your rifle. If you get the odd round that is giving you trouble, bump them all back just a little more.

 

[jakelly]

You need to measure the difference between fired and sized and fired and unsized. This will tell you how much you’re setting the shoulder back.

 

[918v]

Hi,
What I did was to resize the necks and body, w/o bumping the shoulders.

Well if you did that then your shoulder length would increase. Whenever you reduce the diameter of the shoulder and body, the shoulder length increases. Therefore you have to set the die so it bumps the shoulder back to your desired length.

 

[KnowNothing256]

Agreed that you should measure pre- and post-firing to see shoulder movement (better referred to as headspace growth), but odds are decent that you won't see anything until you resize the brass, at which point the cartridge headspace will grow if you aren't touching the shoulder, or stay the same / shrink if you are. If you're getting no issues chambering or extracting, your current die setup is probably fine, but you should take some more measurements to understand the full picture of what your firing and sizing process is doing to your cases. Specifically: headspace of pre-fired, post-fired, and post-sized cases. The 0.002" "bump" is when you set the shoulder back from a post-fired case; this will basically be your new pre-fired and post-sized measurement.

There are plenty of folks out there (mostly benchrest I'd wager) who only neck size, and eventually have to specifically bump the shoulder when they start having chambering and/or extraction issues. Many folks, myself included, aren't willing to risk having an issue on the clock or on a hunt, so we bump the shoulders every firing to be sure.

 

[Sgtsideways]

Thanks to all of you for the help. Is there any way that not bumping back those shoulders would result in higher es and sd numbers?

 

[918v]

No, but why would you not want to bump the shoulder .002” ? You’re already sizing the body. What about shoulder bumping offends you so?

 

[FLIGHT762]

The first time you have to beat your bolt handle open with a 2X4, you'll understand why you bump the shoulders, even if it's .002". You can't N/O size forever without giving the shoulders a bump. You will be able to do it 3-4 times or so, but you will eventually get a stuck case.

N/O can be done, but you have to keep notes on how many times the cases have been fired.

I went through the N/O sizing fad years ago. I learned my lesson. I now F/L & light bump every time. Gives me 100% easy chambering.

 

[John Glidewell]

Videos | wheeleraccuracy

www.wheeleraccuracy.com

watch the sizing brass video. Depending on load, it may take a couple firings before the brass is fully expanded to chamber.

 

[Sgtsideways]

No, but why would you not want to bump the shoulder .002” ? You’re already sizing the body. What about shoulder bumping offends you so?

Not offended, just to my way of thinking not working the brass more than you have to was a goal. Apparently, that way of thinking was stinkin' thinking. For a new reloader like me, there is going to be these experimental questions that make no sense to you more seasoned reloaders. It's just my way of trying to settle things in newbie land.

 

[Schütze]

Not offended, just to my way of thinking not working the brass more than you have to was a goal. Apparently, that way of thinking was stinkin' thinking. For a new reloader like me, there is going to be these experimental questions that make no sense to you more seasoned reloaders. It's just my way of trying to settle things in newbie land.

I’m in the same “boat”, thanks for asking these questions

 

[whatsupdoc]

Eventually the brass will stretch enough to cause excessive force when closing the bolt.
That combined with a little dirt and or lack of lubrication can cause galling of the bolt lugs or action lug abutments.

Whenever you put brass cases through a resizing die even if you dont bump the shoulder back you are causing the brass to flow somewhere.
Where it moves depends on the chamber and the die dimensions.

The reason most people bump their case shoulder back to minus .002 from the fireformed case datum length is so it
will function 100% when inserted back in THAT particular rifle.

Everybody wants good case life but not at the expense of reliability, NEVER.

 

[XLR308]

New Lapua brass measures .0015- .002" under my fired dimensions for the chamber that Kelblys cut for my barrel.
I try and bump them back no more than .0015 when i resize.
Very little effort when sizing and minimal work hardening on the brass considering i also skim cut the necks to clean them up and run them through a bushing Type-S for .002" of tension.