Am loading cartridges for a friend's two BLRs, a .308 and a .243. Although the sizing dies are screwed right down to the shellholder and a smidge beyond for overtravel. Some cases will not chamber. Cases have been trimmed and OAL length for bullet seating does not affect it. Do the BLRs require small-base sizing dies?

MANY BLRs have very tight (small, close tolerance) chambers. Such chambers often give difficulty in chambrering re-loaded rounds.

The easiest cure is often to use a small-base sizing die.

If you start with new cases or at least factory ammo fired in this gun you should be fine. New cases with reasonable charges help a lot for the next sizing/loadings.

Thanks guys. The cases given to me to use by the individual owning the rifle had been fired in other guns. I did raise the ram all the way up and then run the die down to seat on the shellholder. After the nonchambering, I took some of these cases and resized them using the die screwed in a quarter-turn to remove any press slop, going over the bump so to speak. That has worked to eliminate the cartridge chambering problem.

What you have experienced happens frequently in closely cut chambers. I ALWAYS recommend screwing the sizer die down to the top of the ram then 1 1/2 turns more. That will usually eliminate all the slop in the linkage and give you the maximun amount of shoulder set back.

Sometimes you might need to try another sizer or grind 0.005" off the bottom of the die or file a few thou off the shell holder to solve the issue.

Having a case fit like what you're getting is good as long as the base of the case isn't getting squashed too much...if so just polish the sizer inside a few thou with 320-400 grit wet/dry with light oil and have a custom sizer that will keep the cases going and going and going.

Luck

prof - Try this with the resizing.
Remove the expanders, turn the die down until it touches the shell holder then turn a little more. Assuming you have a rigid press this will usually do it. Size a case withdraw from the die, turn 180 degrees and size it again. If you feel like it size it 2 or 3 more times until you think there is no more case movement or sizing taking place. Try these multiple sized cases in the rifles. They should chamber.
Now you need to re-install the expanders and work out a sizing method to make it work with the expanders in place. Partially withdraw a case after the first sizing and turn it 180 without pulling it over the expander. Then resize again.
This technique works with a lot of odd chamber brass combinations and is a good one to use if you are starting out with brass fired in a different rifle.

SR4759,
Without removing the expanders, just adjusting them, I did get the cases sized by screwing the die down a bit. That was all it took. The brass WAS fired in another rifle which I think caused this little problem.
Oh, have never had the problem with my new BLR in .450 Marlin...and loads are over book listings for the Marlin rifle.
Max

I had the same problem.I bought a RCBS small base die and all was cured.

quote:

Originally posted by prof242:
SR4759,
Without removing the expanders, just adjusting them, I did get the cases sized by screwing the die down a bit. That was all it took. The brass WAS fired in another rifle which I think caused this little problem.
Oh, have never had the problem with my new BLR in .450 Marlin...and loads are over book listings for the Marlin rifle.
Max

Prof,
I have a BLR in .358 and have formed old 7.62 GI match brass fired in M-14s to shoot in it.
Sizing slowly helps too. It lets the brass move and take a set.

If you have a strong press what some of the guys are talking about is camming over the press. That's when the ram forces pretty dang hard on the die. What you can do is have an extra shell holder and take a little off the top of the shell holder either with a lathe or flat stone. They are pretty hard.

Remember what hardens your brass is working it..that is shooting it and resizing it. The more you size that brass the harder it will get and you'll start getting case splits especially in the neck first.

I tried sizing a case and turning 180 degrees and size it again. I can't operate my press when it's behind me. Maybe turn 360?

Sounds like you have a personal problem.