308 match chamber, new brass fits, once fired and resized doesn't, ugh...

[SA Friday]

OK. my AICS is chambered in 308 Win match. It's 308 Win, but way tighter. New brass resized and reloaded cycle through it fine. Brass once shot out of my Rem 700 PSS and FULLY RESIZED with an RCBS X-die will lock the chamber up. I can just barely get them to chamber, and after firing, forget ejection without a plastic handled screwdriver and a full length cleaning rod.

Let me be really clear on two things here; the brass is fully resized. I literally cannot get the resizing die screwed down any further. Second, the hard ejection is NOT due to overpressure. These exact same loads have been shot out of new brass in this gun and no overpressure issues. These cases have all the earmarks of a 40 S&W "guppied brass" chamber jam. The belly of the cases are 'shiny' just like they got forced into the chamber before shooting (and they did get forced into the chamber just a tad). This is even an issue with cases shot out of the gun previously, but not as bad. I tried the fully resized (once shot) rounds in my PSS factory chamber and they chamber and eject like they were on oiled bearings. The only two places I can see oversizing cause this FTE is the very back of the neck right next to the shoulder or the back of the case wall near the webbing.

I think the die I'm using isn't getting the brass resized back to factory specs enough and this is causing the jams, but I want to know if anyone else out there has ran into this before. I literally just got back from the range so I haven't taken any measurements off the shot cases and loaded cases but plan on it. I'll post the info later.

Second Question; anyone have any suggestions as to a tighter resizing die? I'm thinking one of the 308 Win carbide Dillon dies might be tighter, but want input before I splurge on the "cry once" die.

[67rschev]

I have ran into this . Had to shave down the shell holder to get a proper resize . I think its Forester that makes different sized / thickness shell holders , maybe someone else can chime in here on who makes them .

[SA Friday]

I have ran into this . Had to shave down the shell holder to get a proper resize . I think its Forester that makes different sized / thickness shell holders , maybe someone else can chime in here on who makes them .

Hmmm. I think since I'm using a multi-stage press, I would look at grinding down the bottom of the die a little. It's not a bad idea.

[67rschev]

EDIT

Now that I think of it , it was with a RCBS die I had this problem . Went to a Redding for my FL , and no more issues . I just took the shell holder to a belt sander and carefully removed a little at a time till the FL sized case fit the chamber .

[car-15]

I use a small base die now, I had the same prob and it solved it. it sizes it to the smallest size recommended so it stopped the sticking problem I was having with my dpms.

http://www.midwayusa.com/product/681...308-winchester
Product Information

RCBS Small Base 2-Die sets are useful for reloaders loading for semi-automatic, pump action and lever action rifles to help ensure that proper functioning. Small base sizing dies size brass to minimum specifications and help to ensure that cartridges will chamber every time. Due to the fact that this product sizes more than regular dies, it is crucial to have a sufficient amount of high quality lubricant to prevent stuck cases.

Technical Information

Material: Steel
Die Types Included:

Small Base Sizer Die (with Expander-Decapping Unit)
Regular Seating Die (with Seater Plug)

Accessories:
Plastic storage case

Notes:
Applies a roll crimp.
Small base sizer dies are usually required for reloading ammunition to be used in automatic, semi-automatic, pump, slide and some lever-action rifles.
These dies size the case somewhat smaller in diamter and also set the shoulder back slightly more than a Full-Length sizer die to ensure poper functioning in the actions of these rifles.
NOT RECOMMENDED FOR AMMUNITION IN BOLT-ACTION RIFLES.
Shellholder NOT included.

ETA: the above, it states it is not recommended for bolt action

[DSB OUTDOORS]

I second trying the small base die sizer. And if your bullet is non canalured I would use a taper crimp vs a roll crimp.

[67rschev]

Being that you are lucky enough to own an AI , I would suspect you are after ultimate accuracy . I understand the use of small base dies , but they work the brass very hard . Having a nice tight chamber , after fire forming once I would look at neck sizing only . Very easy on your brass , no lube mess , and most importantly very consistent neck tension and bullet run out . I still FL size about every 4 or 5 firings as chambering can start to get difficult . Even then , I only set the FL die to just bump the shoulder back a couple of thousands . Along with an occasional anneal , your brass life will be greatly extended . And as far as crimping , I would not . Seems to degregrade accuracy in a bolt gun . Neck tension is better controlled by careful sizing techniques , and leave the crimping for your semi autos . Of coarse YMMV

[SA Friday]

I'm going to try a Forster National Match resizing die and see if I can get deeper on the neck and tighter on the sidewalls. If not, I'll try trimming on the bottom of the RCBS Die.

[Hoser]

Lose the X-die dude.

[SA Friday]

Lose the X-die dude.

Ya, but which one to use now? The Forster sounds like it's built to match chamber specs. Or... is the Dillon Carbide the way to go?

I'm going to try the Forster resized and see if I can get to the chamber dimensions.