Tight chamber?
10-06-2010, 10:41 AM
#1
Typical Buck
Thread Starter
Join Date: Feb 2007
Posts: 538
Tight chamber?
I have a Browning A-bolt in .280 Rem that has about 300-350 factory rounds through it. I decided to work up a load for it even though it has always shot exceptionally well with factory Remington ammo. I measured my max length with a Hornady overall length gauge and seated my bullet about .02" from the lands. When I got to the range, I had a difficult time closing the bolt. At first I thought I didn't bump back the shoulder enough but I had one of the bullets stick in the rifling when opening the bolt. When I got back to the bench, I realized that the modified case was not seating all the way thus causing my Max COL to be incorrect. I attempted the chamber more cases without success. The sizing die was originally adjusted to about 1/4 turn beyond touching the shell holder. By increasing to about 1/2 to 5/8 additional turns I am finally able to barely chamber the cases. Could this rifle have an extremely tight chamber? Could a small base die help?
Additional info - once fired brass through this rifle; all factory ammo chambered fine
Additional info - once fired brass through this rifle; all factory ammo chambered fine
10-06-2010, 11:01 AM
#2
Guest
Posts: n/a
I have a Browning A-bolt in .280 Rem that has about 300-350 factory rounds through it. I decided to work up a load for it even though it has always shot exceptionally well with factory Remington ammo. I measured my max length with a Hornady overall length gauge and seated my bullet about .02" from the lands. When I got to the range, I had a difficult time closing the bolt. At first I thought I didn't bump back the shoulder enough but I had one of the bullets stick in the rifling when opening the bolt. When I got back to the bench, I realized that the modified case was not seating all the way thus causing my Max COL to be incorrect. I attempted the chamber more cases without success. The sizing die was originally adjusted to about 1/4 turn beyond touching the shell holder. By increasing to about 1/2 to 5/8 additional turns I am finally able to barely chamber the cases. Could this rifle have an extremely tight chamber? Could a small base die help?
Additional info - once fired brass through this rifle; all factory ammo chambered fine
Additional info - once fired brass through this rifle; all factory ammo chambered fine
10-06-2010, 11:12 AM
#3
Nontypical Buck
Join Date: Dec 2009
Posts: 1,780
If the once fired brass was fired from your rifle, then your problem is probably bullet seating depth. Bullets from different manufacturers have different shapes, and different seating depths. Try seating your bullets a bit deeper first.
10-06-2010, 11:39 AM
#4
Typical Buck
Thread Starter
Join Date: Feb 2007
Posts: 538
Yes, I did seat the bullet wrong. After forcing the modified case further into the chamber, I found that the max length was actually about .03" shorter than originally measured. I also blackened a couple of cases and chambered, all have the black removed just above the case head at the bulge.
10-06-2010, 11:45 AM
#5
Nontypical Buck
Join Date: Aug 2005
Location: S.W. Pa.-- Heart in North Central Pa. mountains-
Posts: 2,600
....Once you realized the factory ammo chambered up fine plus the fact you were obviously jamming the bullet into the lands, a big red light should have come on for you. By the way... are you lubing the inside of your case necks well? If not, the expander plug can possibly actually pull the shoulder of the resized case forward upon the press stroke removing the case from the die. Guess what happens??.....
