I have a 300 win mag that Ive bin reloading for . Ive noticed that the primer pocket will only take 4 reloads before the primer feels loose during the seating process. Has anyone experienced this with there 300 win mag. I'm using win and rem brass loads are within standard pressure levels any ideas and thoughts will be appreciated thanks slipp
primer pocket expansion rater
- Thread starter slipp
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That would seem to indicate that your chamber may be on the large size and standard loads are giving you max expansion. You may get longer life if you switch to a slightly lower load for practice/plinking.
It may also indicate that the lot of brass you are using is on the "softer" side and is wearing out faster.
Do you have to trim for length after each firing or have you trimmed at all?
It may also be a result of full length sizing the cases each time they are loaded but this one is likely a long shot.
44Bore.
It may also indicate that the lot of brass you are using is on the "softer" side and is wearing out faster.
Do you have to trim for length after each firing or have you trimmed at all?
It may also be a result of full length sizing the cases each time they are loaded but this one is likely a long shot.
44Bore.
Any other pressure signs?.
Brass brand does make a difference in my experience(never personally owned a .300wm, tho)
Freinds that I have reloaded that cal. for, report that Fed., Horn., and Rem. brass, is softer than Win..
Slower burning powders will often give those cases a few more reloads at max. velocities, before the pockets open. Fast/med. burners tend to get touchy at max, in that big case.
Lapua brass lives on and on with the warmer loads. Pays for itself in longevity.
Brass brand does make a difference in my experience(never personally owned a .300wm, tho)
Freinds that I have reloaded that cal. for, report that Fed., Horn., and Rem. brass, is softer than Win..
Slower burning powders will often give those cases a few more reloads at max. velocities, before the pockets open. Fast/med. burners tend to get touchy at max, in that big case.
Lapua brass lives on and on with the warmer loads. Pays for itself in longevity.
thanks guys for your insight to my prob I will try to address some of the questions that have arisen .I took a factory new case and dropped it in the action to see if there was any noticeable play in the chamber but didn't see any the action is a Ruger mrk II and it has a new McLennan 30 cal 1 in 10 twist barrel installed by Joe Kroetsch .I can't see any noticeable signs of pressure the gun extracts easy the primers still have rounded shoulders on them.my load is 76 gr. 7828 with a 200 gr. nos. pt this is a compressed load with a mag. primer .I use a lee priming tool and the primers have a difference in feel as you seat them any real easy seats I reject . Never had one come out and I always use new brass for hunting checking every . I also have another question just how many reloads should I expect from american brass am I just expecting to much from cheep brass if anyone has any more question I will try to answer then thanks again for the time you have given me all your input is well taken thanks slipp
Years ago I did a lot of load development for 300WM. I found that if you neck sized so that you headspace on the shoulder, not the belt, and did not use a steady diet of max loads i could get 10-12+ reloads. I had read all the info about not getting good case life with the 300 and was checking with a paperclip after every firing. Finally I was up to 10 with one batch and figured I wasn't using the paper clip properly and so I took my dremel and sectioned a case to see the case thinning that HAD to be there. Well there was case thinning but just so slight you could barely see it.
Now this was quite a while ago and perhaps American brass has changed a little, I don't know. I know some has because back then, Federal brass seemed to be the most accurate out of the A-bolt I did most of my testing with and it gave good service. I have noticed more recently in other cartridges, Federal brass is hit and miss. Perhaps try a new batch of brass.
Also, Federal primers seem to fit more snugly in primer pockets than other brands if you are trying to squeeze that last reload out of your brass.
Now this was quite a while ago and perhaps American brass has changed a little, I don't know. I know some has because back then, Federal brass seemed to be the most accurate out of the A-bolt I did most of my testing with and it gave good service. I have noticed more recently in other cartridges, Federal brass is hit and miss. Perhaps try a new batch of brass.
Also, Federal primers seem to fit more snugly in primer pockets than other brands if you are trying to squeeze that last reload out of your brass.
You may have a generously dimentioned chamber.
Have a look at the 'pressure ring' just above the belt on the web of your fired cases.
If it is prominent, the case head can expand a bit more at each firing.
.303br is notorious for sloppy chambers shortening case life, and at the other extreme, target/BR brass lives on and on .... because the min. sized chamber leaves the case head with nowhere to go under pressure.
Have a look at the 'pressure ring' just above the belt on the web of your fired cases.
If it is prominent, the case head can expand a bit more at each firing.
.303br is notorious for sloppy chambers shortening case life, and at the other extreme, target/BR brass lives on and on .... because the min. sized chamber leaves the case head with nowhere to go under pressure.
I checked my Nosler, Speer, Hornady and Lyman manuals and all of them stopped before reaching 76 gr's. All rifles are different but I would suspect your load is pushing maximum at best, especially from a custom barrel. It would be useful to know what velocities you are getting.
I have a 300 WM with a custom Hart barrel. At 73 gr's of IMR 7828 my velocities are about what Nosler is getting with 74 gr's.
If you are sure your load is okay, you may want to try CCI primers as I find they usually fit a little tighter than the others.
Good idea. The compressed load isn't a problem as lots of loads containing slow burning powders are compressed. The fact that your load is above what is listed in most loading manuals and you are experiencing loose primer pockets is, however, reason for concern.
In my experience, a larger dimentioned chamber does produce less pressure, with equal loads.
However, that same loose chamber produces more primer pocket expansion than a tight one will.
The case head is unsupported and has room to expand out to the chamber wall, which also tends to expand pockets.
An example; tightly chambered BR rifles, ... those gent's often run with quite high pressures, and yet experience very good brass life.
