Reloading thought

[Crunchy]

So in my 7mag I have been using the same load for a few years.  71.5 grains of H-1000 with 168 grain bergers VLDs, seated at an ogive of 2.725ish.  Did some shooting today after loading up a new batch.  The only thing different was I annealed some of my older brass, and bought a new can of powder.

Results were the annealed brass was way too hot of a load.  So hot the bolt stuck on every round.  I shot the last few rounds of the brass that wasnt annealed and they were money.  The loads were so hot that on the 20 or so rounds I didnt fire I pulled the bullets, dumped the powder and weighed it thinking I was 4 or so grains over.  They all measured right at 71.4ish.  I did measure a few on seating depth, and were a few that were seated a little deeper say 2.716 plus a minus.

Reloaded some of the brass that I shot today dropping the powder charge but keeping the 2.725 ogive.  Started at 67 to 70, four rounds each.  Ideas of what could have caused the REALLY hot load? 

[Magnum_Willys]

Different lots of powder can be way hotter.  Sounds like you got a hot one.

[Hilltop123]

I have my doubts, about the source of the excessive pressure being the brass. I suspect it is the fresh powder that is the culprit.

[Crunchy]

I just cant believe the new lot of powder was that much hotter.  I would guess 4 grains hotter or more if that makes sense.  At 200 yards the new lot was impacting 5 inches higher than the old lot, and I could barely get the bolt to open.  Going to shoot again tomorrow and see if I dropped the charge enough to get back on track.

[CaNINE]

Seen it many times. Different lot of powder is the culprit. Time to recalibrate with the new lot.

[jasnt]

Wow that’s extreme. Did you happen to shoot any over the chrono?  I have burned up pounds of h1000 and never seen results like that

[Crunchy]

Wow that’s extreme. Did you happen to shoot any over the chrono?  I have burned up pounds of h1000 and never seen results like that

I chrono'd the load prior to the new lot at 2940.  Not sure what it was at today.

[Crunchy]

Well I have reduced the load, and putting the finishing touches on the new charge weight.  4 more loads to sample before I decide.  One question, something I hadnt noticed until today, but after shooting probably a dozen loads that were too hot, and dealing with having to man handle the bolt to eject the fired cases, the bolt seems tight.  With or without a round chambered.  I gave it a good scrub, and lube today, but still tighter than it should be.  Thought about putting a bit of lapping compound on the rear of the bolt lugs and working that in to see if it loosens up.  Bad idea?  I even removed the action from the stock to verify.  Same tight open/closing bolt.

[BULLBLASTER]

Lapping the bolt lugs will affect headspace. As your moving the bolt back a small amount

[Magnum_Willys]

Shouldnt take more than 1 to 2 thou to smooth out

[Oh Mah]

Did you happen to check brass with go no go gauge?

Before any lapping is done i would check the bolt for concentricity,You may have bent the bolt some how.I cant see any other way for it to be tight if clean. 

[Yondering]

Well I have reduced the load, and putting the finishing touches on the new charge weight.  4 more loads to sample before I decide.  One question, something I hadnt noticed until today, but after shooting probably a dozen loads that were too hot, and dealing with having to man handle the bolt to eject the fired cases, the bolt seems tight.  With or without a round chambered.  I gave it a good scrub, and lube today, but still tighter than it should be.  Thought about putting a bit of lapping compound on the rear of the bolt lugs and working that in to see if it loosens up.  Bad idea?  I even removed the action from the stock to verify.  Same tight open/closing bolt.

 

For starters, if you fire a round that is hot enough to stick the bolt, STOP SHOOTING! You may well have damaged the bolt lugs by continuing to fire that ammo. Have a gunsmith check it out instead of messing things up further with lapping compound.

Changing powder lots can absolutely do what you described, especially if you're already loading near max.

[Crunchy]

Yes, probably should have stopped sooner with the hot load, but since have dialed it in to about .6 MOA with the new load., which is 5 grains lower than my go to load with the same powder.  Finish the year with it and either going full custom or semi with this action on a new barrell and stock.  If I go semi I will have the smith check the bolt out.

[yorketransport]

What’s your process for annealing the brass?

[Yondering]

Yes, probably should have stopped sooner with the hot load, but since have dialed it in to about .6 MOA with the new load., which is 5 grains lower than my go to load with the same powder.  Finish the year with it and either going full custom or semi with this action on a new barrell and stock.  If I go semi I will have the smith check the bolt out.

Sounds like a good plan.

[Crunchy]

What’s your process for annealing the brass?

Ghetto style with a cordless and socket, and propane torch.  Heated til they get to turn pink, then cool.  Just watched a bunch of YouTube vids and had at it

[yorketransport]

What’s your process for annealing the brass?

Ghetto style with a cordless and socket, and propane torch.  Heated til they get to turn pink, then cool.  Just watched a bunch of YouTube vids and had at it

There's your problem. Your brass was over heated, essentially turning it to putty. When you anneal brass it's a delicate balance between temperature and time. Too much heat and you ruin the brass, too little and you don't accomplish anything. Heat it for too long and the case will heat up too far down the body and soften the case head.

You can certainly use a drill and socket to safely and effectively anneal cases, but it requires a little bit of prep work. Buy a bottle of 750 degree Tempilaq and understand how it works. You need the brass to heat up to 650-670 degrees for a specific amount of time. A higher temp will mean you hold it there for seconds rather than minutes so that's the reason for the 750 degree Tempilaq. Apply a little bit of the Tempilaq 1/8-1/4" bellow the case shoulder. Now hold the spinning case in the torch with the cone of the flame at the neck shoulder junction. You don't want the flame to touch the Tempilaq. Time how long it takes for the Tempilaq to "melt". Do this with 5-10 cases and average out the length of time the cases were in the flame.

If you heat up brass to the point that either the flame or the case itself changes color, you damaged the case and it needs to be thrown away. When the flame changes color, that means that you're burning off some component of brass alloy that the cases are made from (usually zinc at those temps). If the case has been heated up to the point that the neck is glowing cherry red then it's likely that the case body has heated up to the point that the brass is now "soft" too far down.

Your over heated brass lost it's strength and it stopped protecting your action from the explosion in the chamber. That's why you old case that hadn't been annealed still worked fine; it was still doing it's job. Odds are that you did some damage to your locking lugs on the bolt. A steady diet of high pressure loads can cause damage to either the bolt logs or the abutments in the receiver.

Edit to add: This isn't info I just got by doing a Google search. This is a mix of first hand experience and a simplified explanation of what happens during annealing given to me after talking to metallurgist who worked in a foundry for 35 years. 

[BULLBLASTER]

Good info York!

[jasnt]

Have you chronoed the new load?  If your getting the same speed with 4gr less powder then the powder is the issue but if not I’d agree with yorke. 
Either case your lugs and or imbutment are damaged/ heavily peened.   
Can you post a pic of the working side of the lugs?   If it’s something a few thousandths can fix then lapping is fine.  Lengthing head space a couple thou won’t hurt any thing as long as you adjust your shoulder bump accordingly

[Crunchy]

No chance to chrono yet, but POI is the same at 200 and 300.  Haven't had time to shoot further.  I don't think I caused any significant damage, the action just isn't as smooth as it used to be.  Likely the hot loads/bolt issue, but it is grouping great now, and just needs to get me through rifle deer.

York- I was very careful ( I thought) not to overheat the brass, but have limited first hand experience at the annealing process, so there may be some merit to your thoughts.    I am one of those youtube DIYers.  Watched maybe 20 or so vids on annealing, and went for it. 

Things I noticed was that when chambering a round it felt as if I was pushing the bullet into the lands when closing the bolt.  Pulled the cartridge and checked the bullet but found no markings to confirm this.  When I went home I remeasured all the cartridges which were all say 15 thou off the lands.  Rechecked rifle and nothing has changed with this measurement. 

Where would I see or notice issues with the bolt lugs front or rear of the lugs?

[jasnt]

Back side closest to the bolt handle and furthest from the muzle

[Magnum_Willys]

Annealing- I’ve had good luck in dark room, load metronome app to count seconds, cordless and long socket, torch on shoulder,  count seconds til brass just shows any hint of dull red ( in darkened room), thats your annealing time. 

[BULLBLASTER]

Annealing- I’ve had good luck in dark room, load metronome app to count seconds, cordless and long socket, torch on shoulder,  count seconds til brass just shows any hint of dull red ( in darkened room), thats your annealing time.

I’ve tried that a few times and when I use temilaque to check the temp it is never anywhere near glowing.  not any noticeable color at all

[Magnum_Willys]

700 tempilaque?

[BULLBLASTER]

700 tempilaque?

Either 700 or 750. I can’t remember which I got

[Yondering]

Annealing- I’ve had good luck in dark room, load metronome app to count seconds, cordless and long socket, torch on shoulder,  count seconds til brass just shows any hint of dull red ( in darkened room), thats your annealing time.

Dull red, even in a dark room, is at least 300-400 degrees F hotter than you want to be. Whichever magazine writer started that one long ago did a disservice to reloaders everywhere.

IF you have to go by visual appearance, do it in an area with plenty of light, and watch for the case to take on a shiny "melted wax" surface look, and remove from heat immediately. That is typically only 1-2 seconds under my propane torch.

[Crunchy]

Ok, looking to stock up on new brass probably 200 rounds.  Nosler, Norma, or stick to Rem.  Nosler I can find in 7mm Rem Mag, Norma I have not found anywhere yet.  Honey holes for brass I dont know about?? 

[BULLBLASTER]

I’ve been using nosler in my 300 and 7mm. It seems to be pretty good stuff, but I got it cheap. Next time would probably be norma.

[Crunchy]

I am not finding any Norma in 7mm Rem Mag.  No rush, I will keep looking, but if you have any ideas for 200 in same lot, shoot me a PM.