Tight chamber - maybe

kjohn

kjohn

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I acquired a nice NAACO Model 90D 30-06 a couple or three years back. I've done a bit of fun shooting with it, mostly killing rocks at my go to gravel pit.

My last batch of reloads were full length sized, and I found them to be very tight to chamber. I resized them again, FL, and found the cases still a bit tough to close the bolt on. It fires factory loads just fine, bolt closes fairly easily. Hmmm... So Tried bumping the shoulder a wee bit in a .308 die. That worked, but I couldn't bump very far else I would slightly buckle the case. I have the die (a Lyman FL) tightened right up so as to make the press lever snap over. I checked the cases for overall length. They are all either just under the max or right at Max.

It is not a major problem as I will likely ever only use the rifle for fun shooting. I am presuming the rifle simply has a tight chamber, seeing as it chambers factory ammo okay. I like the classic look and feel of the rifle. It wear a Williams Twilight 4x scope, of all things!
 
I think that I have run into that - use a jiffy marker and mark up the case - might not be the shoulder at all?? Might be at the base of the case?? I think I read that Full Length sizing dies do not quite get back to factory spec, but the "Small Base" type do so. I might be off on that. Anyway, starts with knowing where the "tight" is - at the front or at the back...
 
I’ve heard a lot of “tight chamber” issues over the years … of which 99% were eventually resolved with proper resizing. More often than not, either the die is not set properly to resize the full length of the case, or brass is work hardened and not moving like it should. I would try a couple of pieces of brass from a new batch, maybe some of the factory loads that chambered fine.
 
"I have the die (a Lyman FL) tightened right up so as to make the press lever snap over. "

Try turning the die down 2 full revs, so the die hits the shell holder and stops. This is max sizing.

Have you tried chambering a sized, empty case? If it chambers ok, sizing is not the issue. Look to see if there is any sign that the case is too long and the case mouth is hitting the end of the chamber. This would be BAD>
 
Either find an old Bonanza Die set or get a small base sizing die.

This used to be more of an issue back in the days when North American Arms Comapany or Grizzly Arms was still in business.

The chambers in those rifles could go anywhere from minimum spec to maximum spec, depending on how often the reamer had been sharpened.

It happens once in a while on some of the later Remingtons and Winchesters before they changed hands. Maybe even some of the rifles made by these companies when they were in financial distress.

Most European firearms have very close to identical chambers in my experience but not all, especially late war or even early war builds.
 
Thanks for the above input. I'll see what I can do. Sometimes, a body can get bogged down and the solution can be worked out with input and advice from others. This may very well be the case here.
 
Another place to look into is brass flow into the neck thickening the walls. Might not be the most likely issue but if the cases have been loaded several times its a possibility.
Measurements are difficult but trying to chamber a sized case with the expander removed might give you a clue. I would try the above mentioned things first though.
 
I was trying to make some 7x61 S&H from previously fired 7mm Rem Mag brass - full length sized the cases twice - would not chamber completely. Scrape marks on jiffy marker showed cases were hanging up just in front of the belt on the cases. I did not own a Larry Willis collet die then. I tried in my RCBS 338 Win Mag die - those re-formed cases dropped right in to the belt. Then tried my RCBS 458 Win Mag dies - should have been the same, but were not - those brass stopped a good 3/8" or more proud on the belt. I "re-sized" them again with that 458 Win Mag die, and all chambered - so taught me that sometimes "close" or "within tolerances" isn't good enough.
 
Sometimes a case can get so large at the base that it cannot be resized small enough using regular resizing dies. Its not a headspace problem, its the diameter at the base just ahead of the rim.

The way to fix it is as stated above, get your hands on a small base resizing die, and size your cases with that.

You probably only have to do it the first time prepping cases for that rifle. After that you would likely just use the regular sizing die.
 
Maple57 said:
Sometimes a case can get so large at the base that it cannot be resized small enough using regular resizing dies. Its not a headspace problem, its the diameter at the base just ahead of the rim.

The way to fix it is as stated above, get your hands on a small base resizing die, and size your cases with that.

You probably only have to do it the first time prepping cases for that rifle. After that you would likely just use the regular sizing die.
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Usually when cases get that large and won't size down, the brass has become quite hard and just isn't maleable enough to size down and actually ''springs back''
 
kjohn said:
I acquired a nice NAACO Model 90D 30-06 a couple or three years back. I've done a bit of fun shooting with it, mostly killing rocks at my go to gravel pit.

My last batch of reloads were full length sized, and I found them to be very tight to chamber. I resized them again, FL, and found the cases still a bit tough to close the bolt on. It fires factory loads just fine, bolt closes fairly easily. Hmmm... So Tried bumping the shoulder a wee bit in a .308 die. That worked, but I couldn't bump very far else I would slightly buckle the case. I have the die (a Lyman FL) tightened right up so as to make the press lever snap over. I checked the cases for overall length. They are all either just under the max or right at Max.

It is not a major problem as I will likely ever only use the rifle for fun shooting. I am presuming the rifle simply has a tight chamber, seeing as it chambers factory ammo okay. I like the classic look and feel of the rifle. It wear a Williams Twilight 4x scope, of all things!
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It doesn't seem to be the base as you said that using a 308 die to push the shoulder back further "worked". Factory brass tends to be on the small size so that it will work in a large range of rifles.

If it's a few thou you need, you could try a couple of different brands of shellholders with the die camming over tightly on them, or take an extra shellholder and grind a bit off the top of it - but not so much that it's weakened - try perhaps 5 thou to start.

If that works, you've narrowed it down to a slightly short chamber, and you might want to consider replacing the shellholder and grinding the bottom of your die - shellholders can become fragile even with 5 thou removed.

Dies vary and it's possible that a different brand of die would work without any modifications.
 
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Lots of good suggestions here. A fellow CGN'r close by contacted me last night and offered the use of his small base die to try. I will load some with brand new brass and see what the deal is after a firing. I won't be taking this rifle to the Olympics, so I can muck around until I am satisfied. It may very well be a simple solution that hasn't occurred to me yet, but all the input is very much appreciated.

Gotta love CGN. People willing to help instead of criticizing. Thanks!!!!!
 
If you think it is a matter of a few thou, often do not have to shorten the die or take thickness off the top of shell holder - I have several where there is actually a bit of play in the slot of the shell holder - so yes, top of shell holder hits tight to bottom of die, but the case head is hard against bottom of the slot in the shell holder. I used blades from a cheap feeler gauge set and was able to go up to .005" (?) under the case head, in the shell holder - that has the effect of pushing the case that much further up into the die. Might not be your issue at all, but a way to check to see if that will make a difference.

I'll repeat what I said in Post #2 - kind of need to figure out where the "tight" is, in the chamber, before you can adjust for it. As mentioned in posts above, could be at the rear end, could be at the shoulder, could be at the case mouth, plus other things. Marking up a case with jiffy marker, then looking for scrape marks after trying to chamber, seems easiest way that I know to find the "tight" spot. Else, could spend a lot of money on more stuff, that are not correcting the real issue. Since you can borrow one to try, that small base die, set up "normally", is a real good first try, if you have not done that mark up thing.
 
Is the brass from the same rifle? If not that could be the problem. Try brass previously fired in this rifle.

Resize a case from your rifle and try it empty. If it fits ok it's not the brass and you should look at the bullet. If the empty case is still tight then the marker trick will tell you where.
 
I had to go find on Internet - sounds like a NAACO 90D was a 30-06 built on an FN commercial Mauser 98 action - would certainly be hard to find a better 30-06!!!
 
Well, I resized some OF Hirtenberger cases that had been fired in a LARGE chamber (unknown rifle). Wouldn't chamber an empty in my 90D, so I bumped the case ever so slightly in a .308 die. Works like a charm. I have a Lyman turret press, so no problem doing that.

I resized 25 of these cases. Whew! Took some heavy duty grunting. Nice brass, though.
 
Potashminer said:
I had to go find on Internet - sounds like a NAACO 90D was a 30-06 built on an FN commercial Mauser 98 action - would certainly be hard to find a better 30-06!!!
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It is a nice old rifle. I have a weakness for classic style old 30-06 rifles. I have a nice 8x57 on the way, too.
 
vagrantviking said:
Another place to look into is brass flow into the neck thickening the walls. Might not be the most likely issue but if the cases have been loaded several times its a possibility.
Measurements are difficult but trying to chamber a sized case with the expander removed might give you a clue. I would try the above mentioned things first though.
Click to expand...

I'd consider this if you reloaded the same brass several times.
 
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