Is this a pressure sign?

[AaronSDMF82]

Ok ive read about case head sep and the "bright rings" on the case heads.

However I have VERY faint ring BUT its on the headstamp of the brass around the primer, damn near right between the primer, the the stamping of "6mm br lapua"

Is this somthing to be worried about?

Im shooting a 6BR (savage action) 30Gr of Varget with a Berger 90 VLD, laupa brass, 450 primer .020 of the lands, this once fired brass I FL resized with a .266 neck

 

[Steve Blair]

That load should be mild and have no pressure problems. Savage bolt faces sometimes have a concave area around the firing pin hole that can produce odd primer and case head appearance. I had both my 12F bolts bushed by Greg Tannel. I recommend his technique for any factory rifle. He reduces the firing pin diameter and the bushing provides better alignment that a typical factory bolt. Turn around is excellent, usually 2-3 days. I have also had a 40XBR done and all work was top notch. He charges $82, complete with return shipping.

http://www.gretanrifles.com/

 

[RonAKA]

Can you post a photo of what it looks like? Does not sound like a typical pressure sign.

 

[Steve Blair]

Can you post a photo of what it looks like? Does not sound like a typical pressure sign.

While you are at it, can you take a picture of the bolt face, too?

 

[fdshuster]

"Aaron": I see what you're describing on all of my 6BR Lapua brass, fired in 4 different chamberings, .265" and .272" necks. Some to more of a degree, some less. Your load certainly seems well below maximum, and if you have no indications of primer flattening, or cratering, and bolt lift after firing is normal, I would not be concerned. Some of my older Lapua 6BR brass has been loaded between 37 and 40 times, they all have the shiney rub marks on the case head, I'm watching them closely knowing they will soon have to be retired, but more importantly, there have been no pressure problems what-so-ever. I've never had any signs of incipiant case head seperation on any of my 6BR or 220 Russian/6ppc Lapua brass. It just doesn't happen with the cases so closely fitted to the chambers: there is no place for the brass to go.

 

[NorCalMikie]

First off, you say the brass is "full length" sized?? Could be that you've pushed the shoulder back, (more than needed) the bullet is .020 off the lands, the round is fired and the case is being pushed (slammed) back against the bolt head.
If the case was neck sized and the shoulder was bumped " just enough" to stay snug in the chamber and the bullet was jammed into the lands, the brass wouldn't have anywhere to go.
After "at least" 15 to 20 times resizing by bumping the shoulder and neck sizing, I've "never" seen anything close to pressure signs or a case head seperation.
And to my thinking, 30 grains of Varget pushing a 90 grain bullet is getting close to showing pressure signs. You might try backing off 1/2 grain and see what you get?? Also, if the fired case will fit back in the chamber you might try sizing just the neck and see how that works.
In my rigs, I'll show pressure with a given load if the bullet is "jumped" to the lands. That same load with the bullet jammed "into" the lands won't show any pressure and I'am able to boost the charge without and problems. YMMV.

 

[AaronSDMF82]

Same piece of brass, red circle highlights the actual small bright line.
(not the inner dark circle)

Shuster, I saw some of my new unfired brass, and it has similar marks aswell, not TOO worried now. and There are no other pressure signs.

 

[RonAKA]

Just a guess, but I'm thinking this is a high spot on the face of the head. You may want to put an unfired case on a piece of glass that has very fine (600) wet dry sandpaper on it. Do a bit of a figure 8 pattern and see if this same area brightens up. If so, it will likely flatten out with repeated firings.

 

[NorCalMikie]

After seeing the pictures, there's no pressure signs on the case heads. Load them back up and go shooting. ;D

 

[AaronSDMF82]

Ok good deal.

Im going to hijack my own thread here....chronographs

I shot today...at 100 yards, just getting my FPS so I can dope them out.

Before I saw anything further this is my 1st time using a chrono and all my group were sub MOA

1st grp 2873,2867,2911,2855,2861

2nd grp 2930, 2879,2861,2861,2867,2879

3rd grp 2861,2836,2830, 2886,2892

What the hell? Could this be the crono, it was overcast I set the crono 5 feet and 10 feet off on a stand. How fussy are these damn things?
My shot groups looked good...

 

[Silverfox]

Setting your chronograph only 5 feet from your muzzle is too close. Muzzle blast can affect your readings. I'd suggest a minimum of the 10 feet you also listed, but 12 feet from the muzzle might be better, depending on the caliber of loudenboomer you are shooting.

If my math is correct, your ES for group 1 was 66 fps, for group 2 it was 69 fps, and for group 3 it was 56 fps. Not stellar, but if your groups are acceptable, you might be able to live with that high an ES.

Are you weighing all your powder charges or just throwing them? If you aren't weighing them, perhaps your charges are varying enough to give you the high ES numbers. If your brass is case hardened and case neck grip on the bullets varies a lot, that could give you different FPS readings too.

 

[AaronSDMF82]

I have a RCBS chargemaster, I calibrate it every time before use and if it over throws/under throws onetime by.1grain during operation I re-cal.

I must say that Iam a novice reloader however Ive been "by the book" to a tee and treading lightly, I read here more than I post by far.

I Just couldnt see how I would be putting too much powder it.


I was aiming for plus/minus 10 FPS. so Im just a bit dissapointed haha.

I never case harderned by brass, Ill try setting it back about 12 feet or so tomorrow.



This site is outstanding by the way, You guys are No s*** subject matter experts and I really appreciate your postings and knowledge.

 

[bozo699]

Aaron,
In my sons Savage HV varmint rifle in 6br we are shooting 36 gr of varget with a 65 gr v-max this is a lightly compressed load,powder is 2/3 the way up the n/k jumped .012 3550fps w/11fps ES and he shoots 85 gr sierra bthp with 31 gr varget neither load shows any signs of pressure but 1/2 more grain 36.5 grains I was getting shinny marks on the head but still no primer problems, both loads shoot in the .3s
Wayne.