Cases sticking at base

Sailhertoo,
I suppose that you could send the case. I have simply measured and specified, filling in a blank reamer print form. Where I have sent something, it was a dummy round, to get the throat length matched to a particular bullet and a particular seating depth. This is easier to do with an optical comparator than with my simple tools.

The clearance will depend on the application. By the time that you cut and polish the chamber, it will be a bit larger than the print. For a small case, in a single shot target application, I would run the tightest. Graduating up to larger cases and magazine feed, in a field application, I would use more clearance, and for semiautomatic, I would have to do some research. I don't know what the minimum clearances are for reliable function.
 
So Al, The solution to the problem is to get another reamer fitting the "hardened" case dimensions or is there any other way to make these two chambers and dies more compatable, i.e., not having to resize after each firing?

I'm not sure what you're saying re "hardened case dimensions" but I'll try to restate my position. Two things can cause the stickiness, #1 is a too large resizer (this can be fixed with a smaller die) and number two is a too small chamber (harder to fix.) Yes the problem may be a mismatch situation but IME it's more likely a too small chamber. It's NOT the result of the brass becoming "hard."

IF the die is simply too large, which is surprisingly rare, then yes you may find satisfaction by going to a smaller die. "Small base dies" exist for this exigency.

But IF the chamber is too small then your only option is to recut or polish out the chamber.

Here's where it can be nailed down....... turn the case around and insert the BUTT of the case into the chamber. If you've lots of room, if the casehead itself has lots of clearance and the interference is up in the 'web' or body, then you can solve the problem by buying a smaller diameter resizing die.



If, on the other hand, you get a tight fit right off...... your chamber's too small. No resizer except a drive-through will resize the casehead.

Stuff some backwards cases in and write back what you find.

al
 
How would I go about opening up the rear of the chamber a little if thats the route Wes wants to go? 600 grit sand paper after I first set it back up in the lathe? Just do it by feel with a dowel with sandpaper wrapped around it?

Thanks
 
How would I go about opening up the rear of the chamber a little if thats the route Wes wants to go? 600 grit sand paper after I first set it back up in the lathe? Just do it by feel with a dowel with sandpaper wrapped around it?

Thanks
Remember. if you take too much out you can't put it back, you'd have to cut some off and rechamber.

But if you are determined, start with a fired, unsized case as a gage. Then with some 180-220 grit wet-or dry on a dowel rod and polish it out. This is going to be a polish and try exercise. It is not that difficult and many gunsmiths have had to do this. Use a 5/16 or 3/8 dowel. nothing smaller than 1/4" for this size chamber.

If you have a small hole gage, adjust it to the base of the hole, then polish till the gage goes some (???) deeper. Or in many situations you can use the case rim as a gage since it is most times a bit smaller than the case is just ahead of the extraction groove. (reverse the case and use the case body as a handle).

I'd leave the chamber slightly rough from the 180-220 paper. I don't like really slick chambers.

Edit- Polish in your lathe and about 500-750 rpm. Polish for about 30-45 seconds then gage. Repeat as necessary till you get the clearance you want. You will probably not need over 0.0015-0.002" total enlargement. Hold the dowel flat against the taper and try to polish the entire chamber body as a unit to maintain the cone shape of the chamber.
 
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Bad news....the case inserted backwards "is" tight. I do not have any "new" Lapua BR brass and used a piece that is twice fired and not resized without sticking upon ejection. It measures .470 at the base with my digital calipers which are fairly accurate I think.
What has me winding my watch is that yesterday I went to the range with some reloaded ammo in old Lapua BR brass that had been fired 8-9 times loaded up with my pet moderate load (29 Grains of N540) over a 105 Berger VLD Hunting bullet and every one of them went in and out with one finger push and lift and pull. The former chamber was a tight turn neck chamber from which this brass was originally used. Any thoughts? Would it be possible to use this brass (I have plenty) to shoot a match Saturday and expect it to extract as it did without malfunction yesterday?
 
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Bad news....the case inserted backwards "is" tight. I do not have any "new" Lapua BR brass and used a piece that is twice fired and not resized without sticking upon ejection. It measures .470 at the base with my digital calipers which are fairly accurate I think.
What has me winding my watch is that yesterday I went to the range with some reloaded ammo in old Lapua BR brass that had been fired 8-9 times loaded up with my pet moderate load (29 Grains of N540) over a 105 Berger VLD Hunting bullet and every one of them went in and out with one finger push and lift and pull. The former chamber was a tight turn neck chamber from which this brass was originally used. Any thoughts? Would it be possible to use this brass (I have plenty) to shoot a match Saturday and expect it to extract as it did without malfunction yesterday?

GO TO THE MATCH!!!

That old brass is likely well-seasoned and harder than the newer stuff. It'll probably last OK.

I say PROBABLY......

LOL


al
 
Bad news....the case inserted backwards "is" tight.
You need only to use the base, below the extraction groove as a gage and on some brass even it may not start in the chamber. Keep in mind that the chamber is tapered and at best a BR brass rim will only act as a quick and dirty reference, not as a gage to fit by. Unless you are really skilled at measuring tapered holes your caliper will not tell you much.

Sometimes firing a chamber a few times that is marginal in case fit will smooth enough to work. What you may have done is smoothed some of the reamer tool marks, but I wouldn't depend on it. Still sounds like you will have a problem at least part of the time.
 
I talked to Brad earlier and we are going to pull the barrel tomorrow and hit it with a hammer and chisel to see if we can get the brass to fit. If we can open up the chamber some to accept the newer brass I can still get to the range Thursday to get a new zero for the Saturday match. Thanks for everyone's advice and help.
The gun now has 236 rounds down range as of yesterday.
 
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He... He....I'm skert about this....oh well Wes, I'd rather try it on your barrel than one of mine!

We will let ya'll know how it goes or no goes! Four days to match time. Nothing like cutting a chamber to the best of your ability and then having to "sandpaper it out" to work. Looks like Dave Kiff would have given us a heads up if there was a problem with that particular reamer.

I got a gun sitt'en in bedd'en right now with his reamer chamber. 7 saum. Which he clames is the cat's meow. After 4 months wait that sum' bi%& better chamber and extract or I will be paying him a personal visit.


I know, 4 months is nothing in gun terms...... that needs to change... and maybe will with more folks getting into the business.
 
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I talked to Brad earlier and we are going to pull the barrel tomorrow and hit it with a hammer and chisel to see if we can get the brass to fit. If we can open up the chamber some to accept the newer brass I can still get to the range Thursday to get a new zero for the Saturday match. Thanks for everyone's advice and help.
The gun now has 236 rounds down range as of yesterday.

That barrels shot out already Wes!
 
Well here's an update; we decided not to take the barrel off and open up the chamber just yet. I have loaded up for the match Saturday some of the old brass that shot without incident in the rifle earlier in the week. If that works okay I will wait until the small base die comes in and re-size the match brass and see how that goes. If that fails we will take the barrel off and let Brad do his majic. It is shooting tiny holes right now and I hate to take that gun apart until I try this first. Will let you know how it goes.....
 
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