Just when I though I had a basic grasp on reloading! Let me start from the begining, but please read through.

I got my new Rem 700 LSS in 7mm Ultra Mag. I also ordered 100 rounds of Rem brass and, per Lymans reloading manual, trimmed them all to 2.84", and deburred the flash hole. I loaded up 20 rounds of 160 gr. Nosler Partition, with 76.5 gr. IMR 7828 and Winchester LR primers to start with. After reading about breaking new barrels, I shot the first 10 rounds and cleaned after each round. Then I shot 2 rounds and cleaned, until all 20 rounds were done. No problems noted so far.

Then, I loaded up a total of 50 rounds in 5 round batches, all with Winchester LR primers and trimed as stated, starting again with 5 rounds of IMR 7828 at 76.5 gr. and bumping each subsequent 5 rounds up .5 grains.

Today, my partner and I went out to start shooting. All goes well until I reached the loads with 79.5 gr. The first three went off well and really grouped nice, (just over 1"), but I could see a very, very slight ejector mark on two of the three. By very, very I mean that you had to have the right angle of light to see it.

The fourth round in this group also had a very, very slight ejector mark, but also had a huge mark in the side of the case!

Along the length of the case, starting immediately below the shoulder and running straight towards the head, about 3/8" long, there was a deep dent in the case. To describe it better, it looked like I had put the case in a vise and hammered a straight edge screw driver into the brass!. No real sharp or difinitive edges, but a distinct indentation. There was also powder fouling on the case behing the shoulder. I shot the fifth round with the same charge and had no problem but still had some fowling on the brass behind the shoulder.

After talking about it some more, I decided to shoot the next batch of 5 rounds, charged with 80.0 gr. (Don't be afraid to tell me if this was a stupid idea.) The first four rounds went great, with all four touching at 100 yds. The ejector marking was still barely visible with the right angle of light but there was still some fowling on the brass behind the shoulder. The fifth round was off in terms of the group, and also had the same indentation in the brass, along with the fowling.

My partner is not a reloader or gunsmith, but is an armorer and trained by our employer for Glock, Mini's and M14's. He loked at my gun and didn't see anything that he felt would cause a problem.

I also cleaned the bore before each batch of 5 rounds. Although the barrel was cool before each batch of 5 rounds, it was not a cold bore.

One thing of special interest, the relationship between the ejector marking on the case head and the indentation looks to be very similar.

Any ideas on what happened?

Either you left some solvent in the chamber causing the shoulder of the case not to seal
alowing gas to pass the shoulder and colapsing the case or the case slid back losing the seal at the neck causing the results you described.

If you are getting any visible ejector marks, you are over the limit. Normally, you would be feeling some bolt lift resistance at that point, and primer pockets expanded beyond usefulness in one or two loads.

Not sure about the case dents, but I would not like it.

I suggest backing off on the throttle.

Thanks for reminding me about the primers and bolt. There was no primer indications of pressure and the bolt was no harder to open than on any of the other loads.

If the case slipped back, what would that indicate in terms of the chamber length, other than poor, and how would I deal with it.

Solvent is something I never thought of.

New Reloader,
It seems as if you have conflicting pressure signs. The shiney spot on the face is a high pressure sign. If I understand your discription of the case dents, the indent has rounded edges and carbon in it. This is a sign of a slow building of a pressure that is way below normal pressures. This occurs when the pressure is too low to expand the case and seal it in the chamber. The time delay comes into play when the gases are forced around the outside of the case due to the bullet still being in the bore.

The charge you are using is large enough of a very slow powder that standard primers may not giving you enough of a flash to insure proper ignition. I'll be the first to admit that this is a SWAG, but a reasonable SWAG. I have always had very good results under these conditions until I started helping a friend with his .30-378 using H-1000. With this load I found better accuracy using the Fed. 215M primer. In this case we were using between 100 and 106 grains of powder. I'd suggest you run your test again, starting at 74 grains and go up in .5 grain steps, as you did before. This time using either the CCI #250 or the Fed #215M primer. At the very first sign of pressures, STOP. I hope that this is of some help. Let us know what happens. Good luck.

Be sure all oil is removed from the chamber, until it is DRY!
Also, make sure all traces of lube and oil are off of the cartridge cases.
Both can cause high pressures for a novice reloader, or a careless old timer.

New Reloader,

I've not seen this in real life, but I have seen this effect described as a "powder dent" in an article on reloading. In this particular case, the chambering was 6.5x55, and it seemed that there was inaccurate obturation, leading to gases flowing down the side of the case. I have found that the 6.5 is quite prone to this, but a change of primer (in my case Fed 210) sorted it out.

So I'd go with BigBob on this one. It looks like it could be a sign of excessively low pressure. A change of primer is probably the right place to start, but back off the loads a bit too.

The picture below is taken from that article - looks bloody horrible.

Patrick

Pat, that picture is exactly what my brass looks like! Bloody horrible is right!

Thanks for all of the help guys. I'll start over on the charges and with 215's and see how it goes.

Could you tell me what article that was , Pat? I think it would do me some good to read.

I'm gonna suggest there was some extra headspace involved too. With the firing pin driving the case forward for a seal on most of the shots but occassionally igniting the powder while the case was still against the face of the bolt.

Pat,me not being no expert at reloading as I have only been at it about 2 years,I am a little confused at the statement you made about it looked like it was due to LOWER pressures to back the charge off a bit.If you backed the charge off would it not only cause even lower pressure?

Sll,

The comment about backing off related to changing primer. Especially if you're planning to move to a warmer or magnum primer. I should have made that a bit plainer.

Patrick

O.K.,gotcha,lower the load since you are changing primers.As with the rule of reloading,any time that you change one of the components,you should back the load off 10% and work back up.But I still can not get it through my thick head as to how his problem could be due to LOWER pressures since he fired rounds that were 3 grains less bfore he started having the problems.I am not saying that theory is not correct,but I just can't get that to add up.I hope he gets to find the definate cause and shares it with us as I have never seen this happen and would like to know if I was to ever run across it.

Tighter headspacing and magnum primers should solve your problem. If not, anneal the necks so they seal faster.

try a tighter crimp also.

While it has to be gas bleed, headspace or excessive lube are not necessary components.

I experienced this same thing while fire-forming .358 Norma cases with the bullets well up into the lands and after several rounds had been fired with no case indentations.

To avoid pulling the bullets I may decide to bump up pressures a little by putting the ammo in a baggie and leaving in the sun a few minutes before I shoot.

[ 03-17-2003, 17:20: Message edited by: steve y ]

NewReloader
In my experience what you describe is a result of low pressure in that round. As BigBob stated primers are the first step.
Did you inspect each powder charge after you put it into the case? Your problem reminds me of a problem we had with a 6.5x55 we were loading with a stick powder. Once in a while we got a light powder drop becase the powder was bridging in the measure.Most rounds were fine but there was an occasional light round.
To check this I now look into each case and compare the height of the powder charge before seating the bullet whenever I load stick powders.
FWIW
Guy

Here's a thought. Since the round headspaces on the Mag Rim, Is is possible that the chamber is a few thousanths too long creating free space between the shoulder of the case and the front of the chamber, giving the gas a place and opportunity to go somewhere it shouldn't?
Or to put it another way, maybe you have a max specification chamber and minimum specification dies.
While I have never experienced this, if it doesn't occur with factory ammo, it would be on my suspect list.
You might try adjusting your sizing die so that you stop just as it reaches the base of the neck and not allow the die to set the shoulder back.

I've had several instances where gas flow down the side of the case has caused problems. A couple of the lessons I have learned are:
1. When cleaning between rounds, make sure all of the cleaning solution has been removed. I almost ruined a rifle, because the cleaning solution left in the chamber acted like a lube, and didn't let the case properly grip the chamber wall.
2. Watch for dirty throats, and high pressure signs.

a few more thoughts. first of all, i have a hard time believing that this could be lube or solvents as it doesn't happen all the time. also it's not a problem with headspacing on the belt because the cartridge in question doesn't have a belt.

new reloader: did you trim and chamfer these cases prior to loading? inside and out? the reason i ask is that your problem is consistent with an extremely low pressure load however that doesn't make sense in this case as you have enough pressure to cause ejector marks. if you did chamfer the outside of these cases, i think you may have perhaps cut too much of the neck away. i have seen a problem like this only once before, but in that case the fellow was also pushing plenty of pressure but still showing the dent in the shoulder area. closer inspection showed that he had put far too large of an exterior chamfer on his cases which allowed the gases to weasel in around the neck and crush the shoulder/upper body of the case. in that case the excessive chamfer acted as a wedge to allow the gas to pry the neck away from the chamber wall which is the area it would normally seal against.

you can test this theory by retrimming your cases and just barely chamfering the outside of the neck area.

the other thought would be that you are dealing with an over spec chamber that was cut oversized in the neck area. this you can check by measuring the fired cases neck diameter vs. the same measurement on one of your loaded rounds.

my last guess would be that your brass had work hardened in the neck area and needs to be annealed as SST had mentioned. if you brass is near new however, this should not be the problem.

gabe

I think the ejector marks on your cases might be a red herring. I have a model 700 Remington in 264 mag that leaves ejector marks on every round fired in it, factory or reload, high or low pressure. It really looks bad, but isn't caused by pressure. The folks at remington said it could be a weak ejector spring or perhaps just a sharp edge on the ejector port that causes it. After all the trigger and bedding work that I've done on this particular rifle, I'm not sending it back to them for repair of this item.

just a thought,
Graycg

Thanks again for all you help guys!

To answer a few question, the brass was new and came with a note from Midway indicating that Remington brass has been annealed. I did trim and chamfer all of the brass and will check on the dimensions of fired brass vs unfired.

When I shoot, I take one round out of the box at a time and replace the fired brass where it came from, always going in the same order. In looking at the brass that I fired, I noticed that there were other cases with various charges that had powder fouling in the brass. Am I off base here or does that point again at headspace problems with the neck not sealing?

After checking these, I will load another batch and only change the primer. I will let you all know how it goes!

Thanks again to all! I really appreciate it.

NewReloader,

When I started with my 300 rum I had a similar problem. I couldn't figure out where the dents came from, esp since they had carbon inside the dent (ie, the dents existed during/before firing). I posted here and had similar responses regarding pressure, headspace, primers, etc. The problem was that my dents existed through-out my load trials, some of which were pretty hot loads. The dents in my Rem brasses (with 180 gameking in front of 93-99gr of rl25 with cci250 primers) varied from not being there to being as deep as in the pic (only a couple). Finally someone posted that I might be causing the dents by working my bolt too slowly when cycling, denting the next round in my magazine. I'm embarassed to tell you that since then I have not had one dented brass (and the dents pushed out on the next load through). The only question I am left with is this: if the bolt dented the brass, and the dents were subsequently pushed out by later loads (they all look like new now), why were they not pushed out immediately after being caused? I don't have the answer, but I don't have dented brasses anymore, either. And I've settled on a load of 96.5gr (same brasses, primers, bullets, etc with trimming et al), a load that had previously dented.

I can't make any promises, but start simple and work towards the more complex.

Good luck and let us know!
Mike