I’m stumped on this one so maybe someone has some ideas that I’ve missed.

I’ve been reloading for over 35 years, for about 30 different cartridges, and two of my very experienced reloading friends have been trying to help me solve this problem, but we’re running out of ideas.

The rifle is a long range model of Savage FCP in .300 Win. Mag (second factory barrel). Last year I worked up a load that shoots very well in this Savage and a Cooper XLR. With this load both rifles have shot groups around 2.5" at 500 yards so I am really happy with the accuracy. The load uses a Barnes 168 gr. bullet, Norma brass, Fed. 215GM primers and IMR 4350 powder. The charge is a bit above the middle of the Barnes recommended range. Not super-fast, but the velocity SD was under 10 fps and the accuracy was so good that I’ve stuck with it. I settled on .050” off the lands for seating depth.

But a few weeks ago this load I’ve been shooting since last year started showing serious pressure signs in the Savage. The bolt has been hard to lift, the case heads have expanded too much on some of the brass (after just one firing), primer pockets have been loose (again after just one firing), the primers have been flattened and cratered and in a few cases the spent primer has come out of the case. The most bizarre thing is that these exact loads were safe to use last year – up until a few weeks ago.

NOTHING has changed in the load. The loads use the same batch of new Norma brass, same keg of powder, same box of primers, and same batch of bullets. And the same loads still shoot great with no pressure signs in the Cooper.

The bullets aren't crimped and cases are in the correct length range.

Ammo has been kept out of the sun for testing sessions and temperatures were typically 80 degrees or under when the pressure signs were the worst.

Just to be safe I measured the diameter of the bullets and they are fine. I checked my RCBS ChargeMaster against two different balance beams and it’s fine.

I thought maybe I just didn’t recognize the pressure signs when I was working up the load so I figured I would start over to work the load up again. With a near minimum charge (according to the Barnes manual) the primer came out of a brand new Norma case. The head expanded so much the case is junk.

It appears something has changed with the rifle, but I can’t figure it out. It’s been cleaned several times - checking with a bore scope - since the problem started. There was what I thought was a significant carbon ring at the front of the chamber immediately before the throat of the rifling started. I figured that might be my problem. A bench rest shooter friend and I put in several serious cleaning sessions and finally got it out.

I shot the rifle again and still too much pressure…. No falling out primers, but the primers are still too flat, cratered, hard bolt lift and bad ejector mark on the base of the case. So that didn’t solve the problem. It might be a bit better, but the load is still showing more pressure than it did previously.

What in the world could have changed???? This load is fine in the other rifle and was fine for many months in this rifle so I don’t want to change components.

The barrel only has about 200 rounds through it and its really accurate so I hate to get a new barrel. Please don’t give me wacky advice like I need a 6.5, or to get new scope mounts or a different recoil pad, etc. But I would really like some advice if you can think of something I’ve forgotten to consider that would relatively suddenly make the pressure spike of reloads that were previously fine.

BTW – I checked with Savage and they never answered. But that was much better than the official advice from Barnes. Their email back to me said to try a different brand of brass and START with a near MAXIMUM powder charge…. This after I told them I was knocking primers out of new brass with a near minimum charge. Maybe they have a life insurance policy on me that I don’t know about….

Thanks,
Kyler

Make sure you loaded with the RIGHT powder.
Any chance of a mix up?

New jug and different batch?

George

I would try a different brand of brass.

I'm not mimicking what Barnes told you, I come to that conclusion before reading that in your post.

there is one of two things going on here.
1. the load is over pressure.
2. the cases are soft in the head area.

Hi Kyler This may sound crazy but I had 223 savage shot good with factory rounds but my reloads shot terrible tried different powder bullets and brass,then I switch primers and then the accuracy was great. Just saying try different primers. I use federal 210 in my 300 win. mag

It could be the brass or head space. It shoots ok in the cooper. Right ? I would check the head space with a gauge. make sure the brass is not too short for that chamber. Does it have the Savage barrel nut? if so it may have loosened up
Did you have the bolt apart? Forget the washer?
Shootin in the dark.....

Has speed been measured with the high pressure loads?

Can it be tumbling media in the cases (steals volume and spikes pressure for "no" reason)

I know that Norma changed the design of their 300WM cases years ago and clearly stated on their www that the new ones has less volume and needs less powder.

Head space or whatever you want to call it, will not cause increased pressures. Myth.
Only two things can be the cause, assuming everything else is the same like all your components and the temperature.. You already knew that your load was over the recommended one so you should not be surprised when it is.
1: Neck thickness; check it.
2: Heavy Copper fouling.

only other thing that hits me is if the loads were max and loaded in winter then set out in the summer heat

are you cleaning your cases after sizing
The bottom line is, too much powder results in too high of pressures. If you are concerned about pressures, cut your loads.
Ouote
"If you are using lubricated cases, you should set up your sizing dies with a cartridge case headspace gage to ensure that cartridge headspace is within "go" and "no -go". Excessive case headspace will result in action peening, I have no doubt that case lubrication would aggravate action peening, but it will be there dry or lubed cases for cases with excessive headspace."

Double check your case length and seating die to make sure you are not unintentionally severely crimping the bullet either with the die or throat/leade of the barrel.

Thanks for all the advice.

I’m sure anything is possible, but I think I have most of those bases covered.

I could have messed up and used the wrong powder, but I really strive to keep only one keg on the bench at a time. I’ve used the same keg through this process and the loads are fine in my other .300 so I doubt it’s the wrong powder.

Its possible the brass could be soft, but the exact same batch of cases apparently weren’t too soft last year and they aren’t too soft in the other .300.

Barrel nut is tight and I’ve never taken the bolt apart.

Velocity hasn’t been tested well during the times the gun showed higher pressure, but the sight settings on the Savage with the same load as in my Cooper are getting steel plate hits out to 1,000+ yards so I would think the velocity must be pretty similar or the drop would be different.

Some of the brass has been tumbled with SS pins, but never other media. A couple of the primers that popped were with new, unfired brass.

All brass is new, recent manufacture Norma (and works fine with no pressure signs in the Cooper).

I doubt neck thickness could be the issue since several of the problem cases were brand new brass and none of the cases give issues in the Cooper. But I’m starting to think I let the copper (and/or carbon) fouling build up too bad (although accuracy was still good), because since the extremely thorough cleanings it seems to be better (bolt lift more normal and no popped primers).

The load is “middle of the book” and when originally worked up was tested 3 grains higher without showing the significant recent pressure signs. And primers were still popped out of brand new brass with a book minimum charge, so I don’t think it’s as simple as too much powder when the same load was safe last year.

Case length has been consistent in the recommended range and die is far away from crimping the bullet. But possibly the severe carbon ring could have worked to crimp or limit the room for the neck of the case.

This morning I shot the gun a bit more and the pressure doesn’t seem nearly as bad. Maybe getting the copper fouling out and carbon ring out of the forward chamber area made more difference than I thought yesterday.

Thanks,
Kyler

Kyler, are you loading the bullets one at a time or two or more in the magazine. Next, are all rounds showing the excessive pressure? I ask this just wondering if recoil may be further compressing the bullet against the powder. Also, was it noticeably warmer when you shot compared to the last time you worked up the load?

Clean the chamber and bore with a good foam bore cleaner until no more blue comes out of the bore.

Below a 1943 British .303 Enfield rifle with a frosted and pitted bore and using foam bore cleaner without any brushing.



Below bore scope photos of a Savage button rifled barrel with its "speed bumps" that will pick up copper. These type bores will "eat" a copper bore brush and give false readings of copper in the bore.



Below before and after bore scope photos of a fire lapped Savage barrel.



Below a custom hand lapped barrel.



I collected old milsurp rifles and they had frosted and pitted bores from corrosive primers. And foam bore cleaners would remove the carbon and copper with one or two aplications of foam without using a bore brush.

Spare the rod and spoil the bore, before I started using foam bore cleaners I would spend hours trying to get the copper out of these old milsurps.

Below one shot of foam bore cleaner in a AR15 rifle and the first patch out of the bore.

quote:

Originally posted by dpcd:
Head space or whatever you want to call it, will not cause increased pressures. Myth.
Only two things can be the cause, assuming everything else is the same like all your components and the temperature.. You already knew that your load was over the recommended one so you should not be surprised when it is.
1: Neck thickness; check it.
2: Heavy Copper fouling.

+1

Had a similar problem years ago with my .358x.404 IMP. Had put the ammo on my car seat in direct sun light for a fair amount of time . Hard lift with a load that normally gave no problem. roger

Hornady warns of high pressure problems when loading cartridges of this size. They say to stick with near max loadings.

quote:

Originally posted by Smokin Joe:
Hornady warns of high pressure problems when loading cartridges of this size. They say to stick with near max loadings.

Run that by me again.

A "near max load" would result in higher pressure, would it not ? What am I missing ?

I am sure you are very experienced and so are many here.

Just a few thoughts.

Did you check the case capacity of the new brass? May be it is a new lot and they used new tooling at the factory. May be the internal capacity is less than the previous lot of brass.

Did you measure the neck diameter before and after reloading? If the brass is thicker , you will have pressure spikes.

What about the scales? Have they been calibrated?

Do you have any old ammo to weigh and compare against new ammo?

quote:

Originally posted by craigster:

quote:

Originally posted by Smokin Joe:
Hornady warns of high pressure problems when loading cartridges of this size. They say to stick with near max loadings.

Run that by me again.

A "near max load" would result in higher pressure, would it not ? What am I missing ?

They had pressure excursions ( high pressure ) at less than full loading densities

I don't recall anyone mentioning seating depth. Make sure the new high pressure loads are seated to the same depth as the old ones that were fine. Bullets loaded too long can cause rapid pressure rises, and if your loads are compressed, they can push the bullet out of the case over time, since you are not using a crimp.

I can confirm that a bad carbon ring can equal overly tight necks that are that way in a clean barrel. Carbon occupies space. So does copper in the bore. All things considered we all take for granted being just fine and then something changes to take us just over the edge. Hope you find the reason.

Most are missing the point here. The OP says that the same load has been used in his Savage and a Cooper XLR rifle in the past without any issues and now is presenting high pressure symptoms in the Savage BUT NOT in the Cooper rifle "the same loads still shoot great with no pressure signs in the Cooper".
This indicates that something has changed with the Savage rifle itself, whether mechanically which seems strangely unlikely, or a gradual change such as a build up of carbon or copper in the barrel. The OP tells us a carbon ring was observed and cleaned out but with no improvement.

If the ammo is exactly the same batch i.e. a mixed random selection, used in the Cooper with no ill effects then it has to be something changed with the Savage rifle itself.

All this of course contingent on the OP giving all the information and I don't doubt he has, unless a genuine mistake or some confusion has occurred.

quote:

re signs in the Cooper).

I doubt neck thickness could be the issue since several of the problem cases were brand new brass and none of the cases give issues in the Cooper. But I’m starting to think I let the copper (and/or carbon) fouling build up too bad (although accuracy was still good), because since the extremely thorough cleanings it seems to be better (bolt lift more normal and no popped primers).

Actually the OP did say extreme cleaning seemed to help.

quote:

Originally posted by craigster:

quote:

Originally posted by Smokin Joe:
Hornady warns of high pressure problems when loading cartridges of this size. They say to stick with near max loadings.

Run that by me again.

A "near max load" would result in higher pressure, would it not ? What am I missing ?

It's called slow powders do strange things in large cases with light loads. henceforth the near max load suggestion. 4350 seems a little on the fast side and low on the load density scale. I'd bump up to 7828 or RL19.

This is from experience with Norma brass in 300WM, it is SOFT and does not handle many reloads, even with MILD loads.
One interesting thing you HAVE NOT mentioned is the appearance of ejector swipes or marks, without these being present, I doubt there is in fact an excessive pressure event happening.
Primers flatten when they slip in an oversized pocket, just as they do when there is excessive headspace.
Pictures of the cases will tell a lot more of a story, this will help diagnose your issue more precisely.
Without seeing the cases, I am unable to help further.

Regards.

quote:

Originally posted by Kyler Hamann:
But a few weeks ago this load I’ve been shooting since last year started showing serious pressure signs in the Savage. The bolt has been hard to lift, the case heads have expanded too much on some of the brass (after just one firing), primer pockets have been loose (again after just one firing), the primers have been flattened and cratered and in a few cases the spent primer has come out of the case. The most bizarre thing is that these exact loads were safe to use last year – up until a few weeks ago.

I can think of only two things that would cause the chamber pressure to increase, with the same load, powder and cases.

1.Temperature
2. Carbon and copper buildup, with emphasis on carbon buildup in the chambers neck and the necks getting longer.

I have already suggested checking case capacity for lot variance.

How about sizing? Did you do anything different? Any changes. Any measurement of shoulder datum line to base? In other words any over sizing or reduction in head space?

Kyler, when you figure out the over-pressure in your savage share it with me. I have a custom barreled Ruger M77 chambered in 22/250Rem that went from being a load that was very accurate without any excess pressure signs to a load that won't even extract spent cases. Same components and same load. I bought some new brass of a different head stamp that I have loaded up some test loads in but haven't shot them to see what they'll do. BTW, it will shoot factory loaded Federal ammo and extract like a well oiled machine.

Norma has made changes of the weight in their 300wm brass so they have posted different load data for the light and the heavy brass!!!

http://norma.cc/en/Ammunition-...ster-Magnum---heavy/

http://norma.cc/en/Ammunition-...ster-Magnum---light/

Thanks to all for chiming in.

I don’t blame people for wanting to blame the brass, but as I mentioned in the original post this is the same exact batch (bag) of brass as used with no serious pressure signs last year. And nothing has changed with the loading, whether recent or old loadings, of the same brass/loads in the Cooper rifle. The pressure signs only recently got bad in the Savage (or as I’m starting to want to call it… the Salvage).

Many people have suggested neck thickness and case hardness. I know those could be a factor, but the pressure signs were similarly bad recently in the Savage with brand new brass, once fired, forth firing, etc. But none show any problems in the Cooper and these same exact cases weren’t showing pressure signs a few months ago in the Savage. So I don’t think it’s simply the brass.

To the person who asked about ejector marks - it was mentioned in the original post. They were present/bad.

The bullet seating depth has not changed.

And again temperature was brought up. The loads in any session were never left in the sun whether in a vehicle or not and temperatures ranged between 60 and 80 F. I really don’t think that can take any of the blame on this.

I’ve shot it some more and he’s my update: After three significant cleaning sessions (two by me and one by a bench rest shooting buddy), and checking it out recently with the bore scope, the carbon ring is nearly gone and the copper has been reduced to very, very little. The dangerous pressure signs have gone away, but it still might be a bit too high.

I’m thinking maybe the load was originally a bit too warm for the rifle, but because of the great accuracy, very low velocity SD, etc. I tried to fool myself into being okay it. With the fouling building up - for both the carbon ring and copper in the bore - I think it put the pressure indications “over the top” recently.

As was stated by other folks, these Savages really copper up bad and are a bugger to clean correctly. Apparently this rifle likes to collect carbon in the neck too (never had that issue with any other rifle). This was my first Savage and I was making the mistake of putting in about the same amount of time cleaning it as my other rifles. Now having a bore scope, I realize I’ll have to put much more time into the Savage than other rifles.

To be safe, not only am I going to clean more often AND MORE THOROUGHLY, but I’m also going to work up a slightly lighter load for this rifle. I'll look back through my load work-up notes, but I should be able to find a good velocity/accuracy node using a couple grains less powder (but still in the recommended range).

BUT for now I’m still in the throws of sporting clays competition season so more load work is going to wait at least until after I get through the state championships.

Again, the thoughts and advice were appreciated.

Thanks,
Kyler

How about a wet chamber (from cleaning). Would definitely result in a hard bolt lift for a few rounds until all of the lube was removed. Not sure of the primer response to this condition.

If it was me, knowing all that now - I would do the following

1. First I would soak the barrel in Wipeout with Accelerator and clean it a few time along with a Carburetor cleaner to remove the carbon AND metal fouling. Remember that carbon & metal fouling can be layered one on top of the other - several layers.
2. Since you are planning to reduce the loads, I might fire-lap the bore with a few shots using fine grit - maximum 5 shots.

Yes there is the risk that the barrel will not shoot as accurately.

If not, just live with lighter loads and what ever they give you.

All the best.

When this happens to me and it has on occasion I check to be sure I have trimmed the cases properly, usually about every 4th firing..

A new batch of the same powder can be problematic for sure. A new batch of cases can be a problem. These are some of the problems that come with absolute max loads, which I do shoot a lot of.

Head space doesn't cause problems it just fire forms the case and you end up over working your brass..

Thick necks is a common problem and it may be best to outside neck ream your cases and give them a try..

Brass will wear out, especially at top velocity, so try some new stuff or anneal the old stuff, and work up to your old load again.

The above is a starting point, go from there if one of them isn't the problem, Ive named the more common problems and its usually one or two of them..

Its an investigation that only you or an expert can work on, its a process of illumination to find the trouble, patience and careful examination will solve your problem..I would start with annealing, outside neck reaming.

Did you mention the conditions of your primer pockets after firing, were they loose, were the cases ruined? Keep in mind new brass is tougher than fired brass..You can work up a load with new brass, and all is fine and dandy, then at some point the brass stresses and your best hot load is hotter'n a pistol, we fly by the seat of out pants you know, we do not have the needed safisticated equipment, but we get by with experience and a lot of stumbling along the way, a learning experience for sure.