Checking Headspacing and Pressure Using Fired Casings

[Mr. Farknocker]

There's another thread on this but its six years old and i thought I'd start a new one.

I'm new to this this sport, having picked up my first brand new rifle in 8/11 from Sports Authority. It's a Tikka T3 Lite, .270 WIN. Since then, I've fired about 150 rounds of ammo using relatively inexpensive factory ammo, including Winchester Super X, Federal, Fusion (Federal) and Sellier & Bellot.

A week ago, I picked up a copy of C. Rodney James' "The ABCs of Reloading" and started reading about excessive headspacing and learned that if stretch marks/cracks appear on a fired case right in front of the head of the case, it is an indication of excessive headspace. See Photo 1

Armed (excuse the pun) with this knowledge, I examined the fired casings from my rifle and became somewhat concerned at what I found because most, if not, all of the fired casings had a shiny ring in front of the head. Photo 2 and 3. The unfired cases do not have this shiny ring in the front of the head. So far, none of the cases have separated or cracked.

Are the rings an indication of case stretching and if so, is it sufficient to be of such concern that I should have the headspace checked by a gunsmith?

 

[243winxb]

Your brass is normal.

 

[Walkalong]

Looks like normal expansion in a generous chamber. There is a huge difference between that and case stretching/thinning inside.

http://www.thehighroad.org/showpost.php?p=7349348&postcount=17

Check it on the inside to be sure.

http://www.thehighroad.org/showpost.php?p=5844793&postcount=6

.

 

[Elkins45]

Looks like normal case expansion for factory ammo.

 

[alsaqr]

Looks like normal expansion in a generous chamber. There is a huge difference between that and case stretching/thinning inside.

Exactly.

 

[Art Eatman]

Headspace is checked at the factory as part of the normal quality control process. I'll never say never, but I've yet to hear of a headspace problem on a brand-new rifle.

So, since I think it will mostly for amusement: Bend the end of a thin steel wire (such as is sold at hobby shops catering to model airplanes and such) and bend the end into an ell which will fit down through the case neck. Sharpen a point on the end.

If a case is about to separate, you can feel the line of the break with the point of the ell.

A certain amount of flattening of the primer is normal. Keep as a reference a couple of the fired factory cases. If you get noticeably more flattening with a handload, odds are you need to back off on the powder charge.

I've never had a problem with book-max loads in any cartridge for which I've loaded.

Chambers have a small amount of variance from one rifle to another. My pet '06 would take reloads with any old picked-up range brass with neck-sizing only. No way I could do that with my .243; the chamber is on the tight side.

 

[Old Dog Man]

Headspace problem ?

I don't think what your pic. shows is a headspace problem as stated, but I have seen a couple of new rifles with too much headspace. You can check your own by cutting a few shims the dia. of your shell head, and put it on the bolt face behind a new unfired factory round. When the bolt gets tight to close then measure the shim or shims to see what you have. Make the shims from beer, soft drink can that's easy to cut in round shape, it probaly won't do anything, but make you feel better. It shouldn't be much over .006" if so take it to a smith, or call the manuf. Al

 

[Freedom_fighter_in_IL]

Headspace is checked at the factory as part of the normal quality control process. I'll never say never, but I've yet to hear of a headspace problem on a brand-new rifle.

LOL Art, typing quality control and factory in the same sentence nowadays is about like saying Army Intelligence in the same sentence! Now Tikka, as far as I have seen so far, has excellent QC but please don't lump all Factories of today in there. QC is in the damn toilet on most of them.

OP, it's honestly hard to tell from just a picture, but from what I can see, I would have to agree with the other posters here and say yours looks to be pretty normal.

 

[Picher]

If you're planning to reload, don't screw the dies in all the way, but leave them about 1/16" short of full-length sizing. Immediately check to see how they fit in the rifle. If they chamber normally, lock the die at that point and finish reloading.

After firing the reloads, size a case and see how it fits in the rifle. Continue reloading and firing until cases start getting a bit difficult to chamber after resizing. Turn the sizing die until the shells fit nicely, but no farther. Another die adjustment may be needed as brass becomes work-hardened, but at least the die and chamber length will be the same and will greatly prevent case stretching.