Need advice, case head separation

[Short-bus]

Well, it finally happened to me. All this time of checking over the brass to see if I can find any signs of case head separation, and it still happened. My first shot of the day today I was working up a new load of 175smk's and Varget, starting load was 43gr. Touch off the trigger and boom. Only it didn't seem right, there was a LOT of smoke around, more than there really should. Go to lift the bolt, bolt lift was fine, but it wouldn't come back, tried several times of recocking, and relifting, nothing. Finally, I stand up, and give it a light hit with my palm and it comes back, with no brass case. I look up into the chamber area and I see the case head sitting up there detached from the rest of the shell casing which is still stuck in the chamber.

Here's what I need to know please;

1. I've removed the stuff shell casing already, came out without much fuss. What else should I do? Clean thoroughly?

2. I checked the gas ports and they don't appear to have any residue in them, the dust and some grease (not a lot) is still in them, and doesn't look disturbed, is this ok?

3. I've visually checked for anything else out of place, and don't see anything obvious. Do I need to take the rifle to a 'smith and have them check it?

4. Any other advice? I'm going to scrap the remaining Lapua brass that I have, placing the order for new cases here in just a bit. They have 7 or maybe 8 reloads on them now, I do believe that i've officially lost count. They were FL sized each time, which i'm sure accounts for the premature wear, that and some really hot 208/RL17 loads.

Branden

 

[McCrazy]

Re: Need advice, case head separation

Wow, must have been pretty hot loads to wear out Lapua brass in only 7 or 8 reloads. I know several people getting 15-20 reloads or more. Like you said though, full-length resizing every time doesn't help.

Did you have the ring around the base where the case wall goes from thin to thick prior to shooting these? Any warning signs at all?

 

[mdesign]

Re: Need advice, case head separation

1) General cleaning and inspection is all thats needed. I just scrub around in the chamber to make sure the area where it separated is clean.

2) Should be fine.

3) Not necessary to take to a smith unless you want to. He'll just do what you have already done.

4) That many reloads is about all I get out of Lapua brass so I say you did okay. Hot loads shorten the life of brass as do over FL sizing. Both cause excess stretching of the brass which leads to failure like you experienced. Only bump the shoulders .001 when you re-size and it will help the brass last as long as it can.

I run my brass as long as I can but usually you will see the bright ring around the case before it separates. I pitch mine when the ring shows up.

 

[Short-bus]

Re: Need advice, case head separation

I was keeping an eye out for that ring, and I was doing the paperclip feeler check on the inside and wasn't getting any indication.

I'm looking at the possibility of getting a new sizer die that uses neck bushings, and can bump the shoulders back only .002" so I can maximize the life of my next batch of brass. I think Forster makes a good one, i'll be working on my googlefu later to see what options are out there.

Thanks for the feedback on this.

Branden

 

[coldboremiracle]

Re: Need advice, case head separation

Wow, must have been pretty hoty loads to wear out Lapua brass in only 7 or 8 reloads.

I thought I was having problems, I have a batch of Lapua, and after maybe 10 reloads(neck size only) the primer pockets are shot to hell, new primers fit loose and I get gas leaking out around the pocket. No other signs of problems.How many loads have you guys seen out of Lapua?

 

[deadly0311]

Re: Need advice, case head separation

ive got about 50 pieces of 308 lapua that i bought just to experiment with and see if it was worth the cost to me. Im on load # 14-15 IIRC. And i dont have any signs of pressure or loose primer pockets. What kind of charge weight are you using and are you compressing the powder alot or jamming the bullet in the lands?

 

[AJ300MAG]

Re: Need advice, case head separation

Check how much the case is expanding in front of the pressure ring. If the chamber is near max diameter in that area you've found your problem. When you full length size the brass the die pushes the brass back to size in this area, but the brass has to go somewhere. The brass grows in length which causes thinning in the area where you've got your seperation. I've had a couple of rifles that had this issue. Neck sizing solves the issue. I don't buy into the boogyman theory neck sizing is bad. Got brass that's been fired a dozen times, necksized and chambers without any trouble.

 

[coldboremiracle]

Re: Need advice, case head separation

I'm running 44.0 RL-15 under a 175 smk, the chamber is marked .308 match, I assume that means the chamber is slightly different (smaller) than normal. I am however seating the bullets right to the lands (thats where they seem to shoot best)

 

[Short-bus]

Re: Need advice, case head separation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body">i'll be working on my <span style="font-weight: bold">googlefu</span> later to see what options are out there.</div></div>

My Googlefu is strong, I have found my solution, on this site. It'll save me a lot of money too! Going to order a Lee Collet die, and a Redding body die. Total cost.....$43.98 minus taxes and shipping. Cost of the Forster die....$78 minus taxes and shipping, and not in stock. Order the 2 pieces, and new Lapua brass and i've only spent $40 more than I would have if I bought more expensive parts!!

I love this site, i've found everything that I need to know on making quality educated buying decisions on all my firearms related purchases by just using the google searching function for this site. Electronic ear muffs, bubble levels, this threads purchase, powder selections, ect..

Branden

 

[Rafael]

Re: Need advice, case head separation

There is nothing wrong with neck sizing....up to the point where the bolt lift force is more than you can tolerate. A body die will certainly take care of that problem.

Ordering new dies may give you a good feeling but you will not solve the problem of excessive f/l or even body sizing with new dies alone. I would have spent my first money on a headspace gauging tool like the Hornady set with dial calipers or the Redding Instant indicator, or my least favorite of them...the RCBS case-mic.

I size the body every time and have run Lapua brass past 50 reloads with a 175MK or 178Amax and 44.5 grains Varget. My current batch of Lapua is on 10 reloads and the web area is nowhere near thin.
The primer pockets get loose long before separation can occur; when carefully sized. This can be accomplished with most any die. My choice, on a budget, would be the Redding F/L "S" die and bushings.

Just my experience.

 

[Hummer]

Re: Need advice, case head separation

Most 7.62 chambers will measure .471-.473 measured .200" up from rim. The term MATCH chamber is meaningless.
IT IS NOT UNCOMMON TO FIND CHAMBERS THAT GIVE BRASS AS LARGE AS .475"
308 dies will generally size .468/.469.
Commercial cases new unfired generally run .465 at base dim.
LC Cases new unfired measure .468.

Reamers I order measure .468/.4685 at base thusly the base expansion of LC cases is not detectable visually. Very slight on commercial cases.

I also have a 308 die I polished out on lathe to base size .471 so as to not overwork production chambers. I use my .468 to size my tight chambers and the .466 is just sitting there for sizing cases of questionable value such as pick up 7.62 fired in jumbo chambers.

Measure 5 fired cases .200 up from rim, then size them in your dies and measure them and give us your dimensions.

bottom line is closer the die sizes just below fired dimension rules how long you can load them. I can load LC Match cases 75 to 100 times.

 

[Short-bus]

Re: Need advice, case head separation

I got my new brass in this week, and have already gone out and done some shooting. Got my 3rd .1" group with this rifle since I had it built up. It's only a 3shot, so i'm not going to pimp out the pics. I ended up being 44.6gr Varget with a 175smk @ 2.800". Going to load up some more rounds and go shoot it again, this time over a chrono to see the numbers.

When getting the brass ready, it was nice to feel nice tight primer pockets again.

Branden

 

[Jerry m]

Re: Need advice, case head separation

I get 4 loads from hot loaded Full length resized Winchester brass. Use a bent paperclip in the web area there will be a ridge that you can feel before they go completely.

Good luck

Jerry