Once Fired Brass Problems

[Martin52]

 

[Martin52]

View attachment 1235592View attachment 1235593

Top photo is a piece of once fired Lapua Palma brass and is representative of 25 shot recently. All these cases were hard to FLS in my custom die, see the scratch marks. The die was perfectly clean. There is a gap of around 0.010 between the top of the shell holder and the bottom of the die when bumping back 0.001-0.002. This seems to be causing the unsized portion just above the extractor groove.

Load was moderate, 45.2 gr H4895 with Berger 155.5 Full Bore projectiles in FTR rifle, 30 inch barrel.

At the same time, noticed the shiny circle shown on the bolt face at 1 'o'clock in the lower picture.

Seems to indicate too hot a load but I have been using this for a while now. The only difference is that the cases are from a new box bought recently. I am thinking this is a brass problem, maybe.

Thoughts ?

 

[Ledd Slinger]

Did the brass look like that after the first time you sized it, or after first firing?

I've had those same lines appear before on freshly annealed necks when I thought it was a good idea to polish the brass by placing them in a drill mounted shell holder and spinning the necks at high speed in steel wool. It made a perfectly silky smooth brass surface on the necks, but I soon noticed I was getting those same lines on the necks when sizing them. Figured out the issue was because I made the surface of the brass TOO smooth and it was gauling on the FL die bushing surface which was also extremely smooth. Could see the brass residue in the bushings. Quit polishing the necks like that and never had the issue again.

You will hear gunsmiths talking about seeing issues with chambers being too smooth as well that cause rough extractions. If two mating surfaces are too smooth, they will create more friction.

Another thing to consider is that even with the same brand, cases from a new lot can have different internal capacity. Be worth checking the water weight capacity of an old case vs. one of the new cases. If the new cases have less capacity, that can increase pressure significantly.

 

[Martin52]

The brass looked like that after the first full length sizing.

It came new out of the Lapua plastic box looking fine, I expanded the necks and just loaded them up.

I re-sized the first few fired cases, found them problematic, went back to chamber some of the empty fired unsized cases and they would not chamber.

 

[Ledd Slinger]

Usually when empty brass wont chamber again after firing that is an indicator of excessive pressure.

I would measure the internal capacity against older cases with water. You may find the new brass has less capacity. If so, back the load off a couple grains and work back up. Using a chronograph I bet you find you reach the same speeds with less charge weight.

Might also have a die issue with the scratching. Is it a Redding die? I’ve had messed up surfaces on Redding dies that did that before. Looked fine to the naked eye but when sizing fired cases for the first time it scratched the hell out of the base of my brass. If pressure has increased with this new brass you may not have noticed that happening with the die on the old brass because the pressure was less and the head and base of the brass wasn’t expanding as far.

Another possible issue for increased pressure could be that you are developing a carbon ring in the chamber neck. I find carbon rings in just about every rifle my buddies and family bring me to check out when they claim accuracy is falling off.

 

[Martin52]

Yes, the fact they would not re-chamber got me concerned about pressure.
My reloading process is pretty much standardised and I just opened the new box and put the brass into the normal cycle starting with the neck expander.
I have several custom dies from a reputable maker and all have been fine, and I keep 'em clean.
Will have to check for a carbon ring, I generally clean after each match.

 

[Chubbs]

Have you always used Lapua brass or did you change. Lapua brass tends to have less case capacity than others. You may find its around 2 grains less than other makes..

 

[LHSmith]

I am thinking the die does not match your chamber. Also dies cannot size all the way to the extractor groove. This is the solid web area, and cannot be swaged without an industrial press and tons of pressure. That bright ring on bolt, not knowing what firearm- looks like a bolt when modified to plug an ejector hole.

 

[LHSmith]

I would expect to see that shiney ring on the case head and not the bolt face from high pressure.

 

[piie]

The load you used in the virgin brass - is this a load you always used before in virgin brass, or was that load developed over multiple firings? I second the previous suggestion to measure the volume of the cases (if you still have unfired ones) - the problem could simply be that you are putting a "safe" charge in virgin brass that has a smaller volume, and thus raises the pressure - which may then not cause any problems in the fire-formed brass on subsequent loads.

 

[LHSmith]

Did you get bolt click and hard to open after firing?

 

[243winxb]

There is a gap of around 0.010 between the top of the shell holder and the bottom of the die when bumping back 0.001-0.002

Make them contact each other when sizing, at top of stroke. Measure shoulder set back. Will it chamber?

went back to chamber some of the empty fired unsized cases and they would not chamber.

Said to be a high pressure sign. Or oval chamber or bolt face not square to chamber.

 

[cw308]

Martin
Have you measured the unfired cases compared to the brass you used before , your not new to the game . Brass thickness as others mentioned in case volume , and lube. The only thing that came to my mind was when I just received the Redding S Type bushing die , I couldn't wait to try it , instead of giving it a good cleaning , taking it apart to see how things work , I just set it up in the press and had the first stuck case jammed so hard in the die it ripped the head off the body, sent it back to Redding to remove , the CS guy even laughed when I explained what happened. In your case the only change is the dress , even if it could be thicker it should size , even if the press was set up in place using your old brass and swithcing to new leaving everything in place . Would using more lube on new cases help. I've had cases that I could feel alittle more resistance when raising the ram , now after the stuck case , I lower the ram add alittle more lube and it sizes fine . Could it be something that simple . Would like to know for sure what the problem is. Sorry if my post seems lame but sizing should go pretty easy for a experience reloader.
Chris

 

[K22]

What rifle?

Scratch marks look like a rough chamber that I had with a Weatherby Vanguard with created difficult extraction and stiff chambering.

Surprised that you're able to bump the shoulder back with a gap between the shell holder and die. How are you measuring shoulder set back? Are you removing the primer of the fired case that you are basing your initial measurement on? Something doesn't seem right here.

How far are the bullets off the lands?

 

[Webster]

Top photo is a piece of once fired Lapua Palma brass and is representative of 25 shot recently. All these cases were hard to FLS in my custom die, see the scratch marks. The die was perfectly clean. There is a gap of around 0.010 between the top of the shell holder and the bottom of the die when bumping back 0.001-0.002. This seems to be causing the unsized portion just above the extractor groove.

Load was moderate, 45.2 gr H4895 with Berger 155.5 Full Bore projectiles in FTR rifle, 30 inch barrel.

At the same time, noticed the shiny circle shown on the bolt face at 1 'o'clock in the lower picture.

Seems to indicate too hot a load but I have been using this for a while now. The only difference is that the cases are from a new box bought recently. I am thinking this is a brass problem, maybe.

Thoughts ?

Scratches are caused by high points not just rubbing. All of my 6mm Norma Lapua cases size with hardly any effort. I still tell guys that I think a petroleum type lube is the best but no-one believes me. Are the necks chamfered out of the box when you size them. If they are not chamfered tiny nibs of brass will break off the edge of the neck and get in the die. Take the die apart and examine the entire interior with a flash light for brass color. Check the die for machining marks that were not polished out. For starters I would inspect the dies carefully. Lube case well with pet oil and see if it goes away. If it doesn't go away I would complain to the people that made your die. Sounds like your chamber is large compared to the die. I have an off the shelve Whidden die. Don't do competitive shooting. One of the scratches on your case is very deep. It can only be caused by a particle in your die. Last several years I have been using a petroleum based hydraulic fluid sold at auto zone to lube cases. $8 a qt. will last a life time. I had brass scratches on some of my cases similar to yours. It was caused by the necks not being chamfered enough. Removed the brass as much as I could with Sweet's bore cleaner. It has a lot of ammonia in it. Then a light polish with a split wooden dowel wth 800 grit sand paper. You don't have to remove 100% of the brass color just most of it. Sweets might get rid of most of it. I didn't soak for any length of time, I just rubbed it on. Even if the die looks clean it wouldn't hurt to polish lightly with some 800-1200 grit sandpaper. The amount of metal removed is microscopic and of no consequence. Do your cases fall on dirt or concret when ejected? Sounds like the scratches are always at the same location on the brass. What does this indicate?

Does that one deep scratch appear on every case? Some else mentioned a rough chamber? Borrow some elses die and try it.

 

[LHSmith]

Re-read your info. So you have used these dies before with the same chamber and Lapua brass? How are you determining shoulder bump?

 

[XTR]

That load doesn't seem hot. What is the neck on your chamber? Do you need to turn necks for this setup?

 

[Link]

The brass looked like that after the first full length sizing.

It came new out of the Lapua plastic box looking fine, I expanded the necks and just loaded them up.

I re-sized the first few fired cases, found them problematic, went back to chamber some of the empty fired unsized cases and they would not chamber.

It didn't look like that before sizing, but it did after?
I would say the id finish of the die?

 

[Straightshooter1]

Top photo is a piece of once fired Lapua Palma brass and is representative of 25 shot recently. All these cases were hard to FLS in my custom die, see the scratch marks. The die was perfectly clean. There is a gap of around 0.010 between the top of the shell holder and the bottom of the die when bumping back 0.001-0.002. This seems to be causing the unsized portion just above the extractor groove.

Load was moderate, 45.2 gr H4895 with Berger 155.5 Full Bore projectiles in FTR rifle, 30 inch barrel.

At the same time, noticed the shiny circle shown on the bolt face at 1 'o'clock in the lower picture.

Seems to indicate too hot a load but I have been using this for a while now. The only difference is that the cases are from a new box bought recently. I am thinking this is a brass problem, maybe.

Thoughts ?

45.2 gr of H4895 behind your Berger 155.5's is not really a "moderate" load; it's a rather hot load. I've recently fired 45.0 gr. of H4895 to push my 168 smk's in my RPR and that was definitely a hot load for me, which performed quite well without any pressure indications other than a little bit of hard bolt lift. And when I then look at my QuickLoad app to help see what's going on, it's telling me I'm looking at pressure well over the SAMMI max of 62,000 psi and your load looks pretty close the same (like ~65,000 psi).

 

[Webster]

Top photo is a piece of once fired Lapua Palma brass and is representative of 25 shot recently. All these cases were hard to FLS in my custom die, see the scratch marks. The die was perfectly clean. There is a gap of around 0.010 between the top of the shell holder and the bottom of the die when bumping back 0.001-0.002. This seems to be causing the unsized portion just above the extractor groove.

Load was moderate, 45.2 gr H4895 with Berger 155.5 Full Bore projectiles in FTR rifle, 30 inch barrel.

At the same time, noticed the shiny circle shown on the bolt face at 1 'o'clock in the lower picture.

Seems to indicate too hot a load but I have been using this for a while now. The only difference is that the cases are from a new box bought recently. I am thinking this is a brass problem, maybe.

Thoughts ?

Why would a hot load make a deep scratch? Is it on everycase?