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.