excessive case stretch after one firing with sticking cases

[drum13]

Federal .308 cases stretching from normal (just trimmed 2.0030-2.0035) -to- 2.0131 on average.

The cases stick in the chamber after firing, sometimes requiring forceful means to get them ejected. The fired cases will also stick in the chamber (700 SPS) if put in lightly by hand. At first I thought the headspace on the rifle was short but it checks normal.

Cases have numerous full and neck sizings on them but I've never encountered this much growth after one firing. No signs of over pressure. Should I junk the brass?? Thanks.

 

[M14 Shooter]

That seem like a lot of growth for one firing.I have not been a fan of Federal Brass for reloading.I like Lapua and Lake City LR Brass . I do not think that that the length of the case is causing you extraction issues .Factory chambers are usually long in the throat to keep pressure down.If the brass was shot out of an auto loader before you sized it .You may need to use a small base die.
But my advise would to be buy a few hundred cases of Lapua brass and call it a day.

Regards Mike

 

[drum13]

Thanks Mike. The cases might have been fired out of my AR10 1-2x before but don't have exact data on the cases. Been reloading them for quite a long time though.

A few of the fired cases fit in my other 700 (5R) but the bolt is hard to close. The bolt closes fine on the SPS with the empty fired cases but they stick in the chamber. This is driving me nuts. I polished the chamber and lapped the lugs on the SPS and cases still stick unless trimmed to spec. However the 5R eats anything & everything.

I'm thinking it's the brass because the one piece of Winchester brass mixed in with this batch was perfect.

 

[BuzzBoss915]

I don't have an opinion on the cause of sticking or the length issue, based on incomplete information, but. I strongly suggest more discipline in segregating your brass. You don't have to do things my way, but it would solve some problems if you did. Dedicate specific brass to a specific rifle and never mix them. Yes, it would be good to buy the best you can afford, but there are many people that specifically advise staying away from Federal commercial brass in favor of lake City, WW or Lapua. BB

 

[drum13]

Appreciate your reply, BB. I agree on the segregation of brass, now that I've got more than one 308 I will do that from now on. Got a ton of PPU cases that I save for the AR10 as the brass seems to be tougher.

Have had excellent luck with this batch of Federal brass despite all the bad press. They were FGGM originally. Thought they would be fine for the SPS as they shot great in the 5R for well over a year.

Please tell me what further info is needed to investigate the case sticking issue on the SPS?

 

[BuzzBoss915]

Just a guess. Possibly your extractor is fouled with extruded brass? Are your hand loads completely free of lube? Will a factory round chamber and extract/eject without a problem, as with the single WW case?

How aggressively did you lap the lugs?

By the way, I am just repeating what others have said about Federal because I personally do not use it, never have. BB

 

[drum13]

Since I found the cases would stick in the chamber when loaded by hand (bolt not even in action) - I ruled out the extractor.

Cases were free of lube and tumbled. Even tried firing same brass a few times in the same rifle, then neck sizing & trimming, firing, again FL sizing & trimming and over again...still sticks.

I only lapped the lugs and polished the chamber after I couldn't figure out why the cases were sticking. Polishing helped a little but lapping didn't do much....I was sure not to go overboard with it, just until about even wear on both lugs.

The only factory ammo I have on hand is 1 box of 168 SMK Fed GMM and they feed & extract smooth as silk. Seems any other 1x fired brass sticks in the chamber even when loaded lightly by hand a partial way in... some brass sticks so bad I need a cleaning rod down the muzzle to force it out.

Yesterday at the range I was shooting FL sized & trimmed, tumbled to shiny clean of 175 SMK w/43 RL15. Most all the fired ammo stuck to a degree and required effort to eject. Some were stuck so bad I had to repeatedly slam the butt off the ground while pulling the bolt. Most of those extremely stuck cases were measuring 2.0130-2.0145 in length. This was after one shooting and trimmed to spec before one firing.

The rifle has been like this since day-one, it has 315 rounds through it. It shoots great, thru the same hole at 200 yds when/if I can hold steady..... but this issue is driving me nuts!! Unfortunately I don't have the money for a gunsmith, Lapua brass or factory ammo (seriously) - so it would be great if I can get it resolved at home.

 

[speedygoss]

Take the rifle to a gunsmith and have him re-polish the chamber. I had the same exact thing with a 7mm Sendero. After weeks of trying everything it ended up being the chamber that was too smooth of all things.

 

[givey]

+1 on the small base dies. I have the same issue with brass fired in my AR-10 when attempting to chamber it my R700. A small base die solves the issue.

 

[buffybuster]

The difficulty you're experiencing with extraction is most likely due to casehead expansion and not a headspace issue. The chamber in the SPS seems a smigde tighter than your 5R.

The best thing is to start over with fresh brass and SEGREGATE brass to individual rifles. Then get a headspace comparator gauge and set your resizing die to the individual chambers, that will extend brass life.

If you're deadset on using the brass through all the rifles, then you need to get that headspace comparator and determine the shortest headspace to set your die and use a small base die to size down the casehead. You'll sacrifice case life for the convenience.

 

[witchhunter]

Mark a round with a sharpie and chamber it. You will see where it is tight. I feel you will find it in the base area, not the length. Dedicate one set of dies to each rifle along with the brass. Adjust each die to each rifle's chamber. That way they will always fit.

 

[mcfred]

Federal .308 cases stretching from normal (just trimmed 2.0030-2.0035) -to- 2.0131 on average.

Is your decimal point correct? So they are stretching 0.010 inches? i.e. "ten thousandths"? This is not all that bad with regular FL dies. Also, are you measuring fired brass with primers in them? I've seen primers stick up 0.005" so you could try re-seating the fired primer to take a measurement or else push it out first. You can fine tune your reloading setup to reduce this stretch to get better brass life if you want.

As far as sticking cases, does the rifle have any cam on opening the bolt? I've handled a couple new remington 700's in stores that basically had no cam. This means you are trying to pull the case out of the chamber with no mechanical advantage. You should be able to take a chunk out of the rim when trying to open the bolt on a stuck case. If the cases really are stuck, then there is probably a groove in the chamber. Do the removed cases have shiny rings or clear rub marks? If there is just no cam then the bolt and/or bolt timing should be looked at.

 

[drum13]

Well I broke down and dropped the rifle off at a smith this afternoon. I'll let ya'll know what the outcome is.

The brass is pretty old and has had numerous firings on them. For Federal it held up really well and I got some very accurate loads out of them. I'm sure it's near the end of it's life anyway. But what concerned me most was the cases sticking because the fired-brass fits in my other Remington without sticking.

Definitely couldn't take a chunk out of a case rim and I pulled the bolt with a lot of force. At the range, had to resort to slamming the butt on the ground while pulling on the bolt to get some of the cases out. I couldn't find any clear rub marks except for light vertical scratches which I think is mostly from the new feed lips. There were some tiny dents at the top rim (chamfer area) of some of the stuck brass but nothing that really stuck out as being a problem.

 

[mcfred]

Definitely couldn't take a chunk out of a case rim and I pulled the bolt with a lot of force.

This sounds like no cam to me. Lifting the handle should bring the case back ~1/8" and it should be loose by then.

 

[drum13]

To add to McFred - The bolt was a bit sloppy when opened but nothing out of the ordinary for an SPS I'd say. Never thought of the cam, that's a good point. But the fired cases would stick by themselves inserted into the chamber by hand - without closing the bolt. I used a dental pick to remove one case by the rim and it was really stuck in there, the brass had only been pushed into the chamber lightly by hand and stuck probably only 3/4 of the way in. This was repeatable with other pieces.

 

[drum13]

This sounds like no cam to me. Lifting the handle should bring the case back ~1/8" and it should be loose by then.

Nope, I could lift the bolt handle up & down a 100 times and did nothing on a stuck case. They were really fkn stuck in there.

Hmm... I'll let the gunsmith know your thoughts on the cam. Thanks for the help!

 

[bruddah]

Interested to hear what you find out.

 

[drum13]

Hopefully picking up the rifle tomorrow. I'll be sure to update.


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[72Stick]

Me too!

My AR10 just started having issues with several stuck cases. Issues included a FTF and not locking the bolt back on the last round, when it doesn't have a stuck case in the chamber.

 

[drum13]

I'm picking up the rifle tomorrow from the smith. I think the issues were mostly due to my brass. I'll post results.
If you're reloading for the ar10 I'd start troubleshooting there at the reloads especially if it wasn't doing it prior.


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[drum13]

Picked the rifle up from the gunsmith today. It was an expensive lesson.

Been reloading for a few years now and haven't experienced "hardened brass" yet. The brass is tired and has no elasticity left. it's been reloaded over a dozen times and never annealed.

The case-sticking issue was from hardened brass and the excessive stretch was from a combination of both, the bumped shoulders and hardened brass.

Bumped shoulders increased chamber pressure resulting in excessive case stretch. Being hardened brass, the cases have no elasticity so the necks would not shrink back to size after firing.

Since troubleshooting the case sticking issue, I took the FL die apart to clean it. Might have turned it down too much when setting it back up in the press.... accidentally bumping the shoulders back. I need to spend more time setting up my dies and not just going with the LEE settings found in their die's instructions. (which is what I've been doing for years without issue, until now).

The rifle's headspace checks out fine and the chamber was cleaned. The smith shot some factory match ammo and a few reloads through it with no sticking-cases or case stretch. Glad I at least had the sense to bring my fired brass and a couple pieces of prepped brass to the smith's.

Hopefully this thread will save somebody a little frustration.

 

[Victor N TN]

Another consideration:

If your brass is INDEED growing 0.010" after firing, then being hard to extract the cause MAY be the brass is forming out into the rifling. That would surely make it hard to extract.

Don't let anyone polish the chamber too much. There has to be friction to keep you from having a bolt in the face. Like putting motor oil on rounds before you fire them. A disaster fixing to happen. The first round may hold. So may the 25th. But the bolt lugs and receiver are being punished a lot.

The chamber doesn't have to look like a gravel road. But certainly not like a mirror either.

Good luck & be careful.
Victor

 

[jsthntn247]

You need a hornady case bump insert for you calibers that measures shouder bump. Only bump the shoulders .002 each after each firing. Set the die up for YOUR brass and not the way the manufacturer says to. Anneal your brass after no more that 3 firings. Do a search for annealing brass with a propane torch and spark plug socket. That's still the way I do it.

 

[drum13]

Another consideration:

If your brass is INDEED growing 0.010" after firing, then being hard to extract the cause MAY be the brass is forming out into the rifling. That would surely make it hard to extract.

Don't let anyone polish the chamber too much. There has to be friction to keep you from having a bolt in the face. Like putting motor oil on rounds before you fire them. A disaster fixing to happen. The first round may hold. So may the 25th. But the bolt lugs and receiver are being punished a lot.

The chamber doesn't have to look like a gravel road. But certainly not like a mirror either.

Good luck & be careful.
Victor

Thank you Victor. That's why I wanted a smith to look everything over. They only cleaned the chamber and said the polish I did was good. I just used 0000 steel wool.

You need a hornady case bump insert for you calibers that measures shouder bump. Only bump the shoulders .002 each after each firing. Set the die up for YOUR brass and not the way the manufacturer says to. Anneal your brass after no more that 3 firings. Do a search for annealing brass with a propane torch and spark plug socket. That's still the way I do it.

Yes, I need one of those gauges for sure. The smith had one and graciously took time out of his day to show me what was up with my brass sizing's using the Hornady bump gauge and the LE Wilson case gauge.
I will go with your bump recommendations next time I size. Should I also do this when neck sizing using my Lee Collet die??
Thank you.