I have some once fired Winchester brand .308win brass that about 2/3 of them won't slide easily (some not at all) into the RCBS trim-pro shell holder (#3 holder) to trim.
The rim seems too thick. They were fired in a Kimber model 84M loaded with sierra 165gr gamekings, 45.5gr Varget, CCI200 primers and chronographed at 2725fps with 0.7inch 5 shot groups at 100yds. All brass fit under the shell holder when I initially trimmed them as new brass. 35Whelen, 270Win, 250Savage, 30-06 brass all fit fine in the same shell holder. With the components, velocity, rifle used, "followed the handbook recipe", etc I see no red flags of pressure or other problems. What's going on?? I ended up using a #12 holder and they were a bit loose, but was able to trim them up fine- allowing the rim to spin a little in the holder to center them with the pilot and easing into the actually cutting.

If they fit the shell holder once, the only way they won't fit again is if they expanded under pressure. I had some 308 brass that was very soft within the past 3 years ((forgot the make, might have been Win) , and reacted like yours does; I threw it away. The rims were expanding and the primer pockets were not tight any more. . I was not using hot loads at all. Solution; don't use Win 308 brass any more.

your recommendation?

I'm not familiar with the RCBS Trim-pro shell holder, but I suspect that your problem is not that your rims are "too thick", but that, as dpcd indicated, they are too large in diameter due to expansion from excessive pressure.

Have you tried repriming these "too thick" cases? If so, do the primers have the same resistance to seating as before the cases were fired? My guess is that they seat rather loosely.

The recommendation is simple: Reduce the pressure. The excessive pressure could be caused by using more powder than this particular rifle will handle, or perhaps seating the bullets long enough that they engage the rifling when chambered. It could also be a result of case necks which are thicker than the chamber will allow (will a .308" bullet insert into a fired, unsized case mouth easily?)

It is possible that the nominal pressure of your loads is within the normally accepted range, but that you have a batch of brass which is too soft in the head area. This is unusual, but can happen (particularly if someone attempted to anneal it and got the head area hot.) The definition of acceptable pressure is that which does not damage the brass case within a reasonable number of firings. If your pressure is damaging your cases upon a single firing, then regardless of what absolute pressure your loads are running, the pressure is too high for the subject cases.

As I said, my situation was not due to high pressure loads and the primer pockets were getting loose after one shot. Primers and extraction were normal and I was using more than one powder, and not at the top of the chart. You are right, those loads were too much for that particular brass. Soft lot of brass. My solution was to not use that brass any more as those same loads reacted normally in other makes of brass; Federal and Lake City Match.

I have some 270Win (RP brand) brass that has the same issue as your 308 brass. I just throw them into the junk brass bucket when I find them. I don't know what caused this though.

quote:

RCBS trim-pro shell holder

Are you using a #3 shell holder and #1 collet? Is the #3 a rcbs shell holder? if its a hornady , redding or lyman they are different.
Did you try re-chambering ? and do they fit the bolt face?

If they fit the original shell holder, you do not want to find a bigger one; smash the necks with a hammer so you won't use them in the future. That is what I do.

The second and third priming of this brass felt normal (not loose). The reloads do chamber and shoot fine. I'll take your advice however and junk them after the next firing and try another brand. Do you suppose Winchester would be willing to "make it right" with this brass?

quote:

Do you suppose Winchester would be willing to "make it right" with this brass?

That's very doubtful. The manufacturer will tell you it has no control over its brass once it leaves its possession. Reloading brass is subject to a plethora of different treatments by reloaders; different methods of sizing, different levels of pressure, different shapes and sizes of chambers, different annealing processes, etc., etc. That makes it almost impossible to demonstrate that a problem was caused by a manufacturing defect in the brass.

From time to time, when a particular lot of brass can be identified by lot number and that particular lot number gives the same problem for multiple consumers, then the manufacturer is able to identify a manufacturing defect and will issue a recall. This mostly happens with loaded ammunition which has a lot number on the box (as opposed to bulk reloading brass which typically has not lot identification). And the defect with recalled ammunition is usually not in the brass but in the powder or some other component.

They definitely won't take it back after it has been reloaded; the clause "we have no control over whatever you might do to it after it leaves our plant and therefore we won't be responsible for it....", applies. Just move one; it happens.

Problem solved duh!-- I assumed if the RCBS shellholder #3 was used, then the #3 collet is also used. Wrong- #1 collet is the correct one. All these years I've assumed wrong. Hope this helps some other poor lost soul.

If I had more closely read hivelosity's reply I'd have figured this out much sooner.

Could be your primers have backed out a little and this could be why they won't go in shell holder. Try knocking out a few primers and then see if they fit. Some shell holders don't have a relief cut for primer.

They've been sized and deprimed and fit fine in a "shell holder" for the press, but some don't fit in the collet of the trim-pro (not the trim-pro 2)case trimmer. After further research (correct me if I'm wrong) the original trim-pro collet number to use is the same as the shell holder number which in the case of 308Win is #3 for both. The new trim-pro 2 uses a totally different collet system and the number to use would be #1 for that system. So I'm back to where I started with brass that can't handle what should be middle of the road pressure for this cartridge; both surprising and frustrating. Thanks for the input.