Questions about brass, OAL, etc...

[Afy]

I have noticed that quite a few of my cases have necks that have been bent a little out of shape. The neck holes have become a little squished. No evidence of any cracks etc... checked under a magnifying glass.

This is all once fired brass, so do I just let the neck re-sizing die fix it for me and carry on as normal, or do I toss the brass. (Its all Sako or Federal)

Then is the trim to length.
For example the Lyman manual gives me a trim length of 2.620 inches for the .300 WM and the Vithavouri Manual 2.610. My brass is all in the range of 2.613 - 2.618 so should I trim to 2.610 or not bother? Also how much lower than the trim to length is safe?

Finally the OAL for the caliber is listed as 3.340, I checked a few factory loads from Sako and Federal and they are more in the 3.2x range. Is it OK to be under OAL?

Also if you're using Berger VLD's its going to be next to impossible to be in the OAL. How does one determine the safe OAL in that case?

Thank you as usual for the help.

 

[Steve C]

Small dents are taken out in the sizing operation by the expander ball. If the dent is too deep or the neck if flattened then you may not be able to get it to resize or the case mouth could be damaged during resizing. Simply inspect your case after sizing and discard any that obviously will not hold a bullet. Discard any that will give you problems in the sizing operation, its something you figure out with some experience.

OAL's listed in the manual for the caliber are usually the "maximum" length and not necessarily the length you want to load to, the various OAL's you see in the manual that differ from this is where they seated the bullet in developing their load data. Factory ammunition is generally seated short of the Maximum OAL since its being made for any number of different rifles all that have slightly different chamber and magazine dimensions and the ammo has to work for them all.

How does one determine the safe OAL in that case?

With rifles and their large cases OAL isn't a "safety" issue but a feeding and accuracy issue.

OAL is usually determined in 2 ways. For target ammo its usually best to set the OAL to just off the lands by a thousandth or two, there are several techniques to determine this from a loosely fitted bullet in a case to a gage designed to do this measurement. For hunting ammo use a factory load to set your OAL to assure feeding from the magazine unless you feel confident that your "target" OAL will feed reliably.

Once your OAL is selected, develop your loads charge starting at the start weight and working up to the optimum accuracy and velocity.

It's best to have the cases at a uniform length. How much this adds to accuracy is questionable and dependent on the cartridge and rifle action. Competition target shooters want to have everything as uniform as possible. Hunting or plinking ammo it may not be worth the time if the length is still under max specification but that's your call. Make sure to check case dimension and determine if they need to be trimmed after sizing. The cases will change dimensions a bit when sized.

 

[skinewmexico]

I like to use a Stoney Point gauge, now Hornady L-n-L, to determine seating lenght in my reloads.

 

[The Bushmaster]

If the mouth of the case or any part of the case is dinged enough to leave a crease discard it in the recycle bin...Otherwise resize it and reload it...

 

[Afy]

Thankyou all for the information.

Back to the recipie book...

 

[mkl]

One word of caution if you choose to adjust your OAL so the bullet is a couple of thousandths off the lands.

Be sure they will fit in the magazine.

I like to load my most accurate rifles that way and never had a magazine fit problem. Years ago on a deer hunt, my buddy forgot to pack his ammo so I loaned him half a dozen of mine since we were both shooting .243's. I was sure it was safe since my reloads were sligltly below the minimum load in the books. He got to the deer blind and found my ammo was too long to fit in his magazine, so he ended up with a single shot rifle. One more good reason "not to lend others your reloads."

 

[Bitswap]

Sounds to me something is wrong. The only way necks should be dented is by stepping on them. If they're coming out of your chamber dented you have a serious problem with the length of your brass and not trimming properly.

Hard to tell if these are reloads or not, or if you have a custom chamber. I would advise that at minumum you have 0.005" less than the COAL. I usually do 0.010".

What concerns me is this is one thing in reloading that will cause you great harm and is very important to get right.

Make sure you measure and trim the brass as the last step in your case preperations. Sizing will increase the size. If in doubt, use the specifications in reloading manuals.

If your sure your doing things correctly, you may try annealing the necks after sizing them. It depends on how badly they're deformed. If deformed too badly, toss them.

I'd focus on why they're deformed in the first place.

 

[Afy]

Technically not the neck but the mouth of the case. Newbie... so the language is still on the upward curve...
Some have become ovalish.. probably becase I steped on them.

I generally load one cartridge at a time. So am not too worried about the magazine.

No creases in the brass... am erring on the side of caution and tossing any brass I have doubts about. So far that is about 30 % on my once fired cases.

I broke my camera, else I would take pictures and post them...