Just bought a Ross MkII** without an enlarged chamber. Full length resized brass though Lee dies does not size down towards the rim enough, and the brass doesn't enter the chamber. Scuffs are around the base of the brass, about 1/8" up from the rim. Any suggestions? Would hate to buy a custom FL resize die just to size a little closer to the rim.
.303 Base sizing for Tight Chambers
- Thread starter Sharps45-70
- Start date
nowarningshot
CGN Ultra frequent flyer
Wondering if you could use a die from another caliber. Would have to check the schematic brass dimensions, take out the deprimer/inside sizing ball. Then run it back through the the 303 sizing die.
Not really sure if I'm talking out of my ass, or over thinking this. Simpler solution would be to buy a non Lee die here in the EE. It could just be a die made on a Monday morning.
A lot more generous chambers in LE than Ross. One of the issues with Ross, no allowance for the mud n blood of WW1 trenches.
Not really sure if I'm talking out of my ass, or over thinking this. Simpler solution would be to buy a non Lee die here in the EE. It could just be a die made on a Monday morning.
A lot more generous chambers in LE than Ross. One of the issues with Ross, no allowance for the mud n blood of WW1 trenches.
This. Are you using factory ammo, new brass, or 1F brass out of an Enfield?
If you are using brass from an Enfield that is surely your problem and you should source virgin brass for your rifle.
- Location
- Western Manitoba
That is going to be tough. I looked at the Lee Shell Holder #5 in my Lee 303 die set. Just using a steel ruler and Mark I Eyeball, it seems the shell holder top is about 1/16" above the rim, so nothing that uses a shell holder will get at that part of it. Then, I note that there is a rounded portion on the bottom of the die - the internal ground part is perhaps another 1/16" above the top of the shell holder. So, even if you sacrificed a sizing die - grinding the bottom of it flat and cutting it off so the shoulder isn't bumped, you could only gain 1/16" - half of what you need - using a shell holder? SAAMI chamber drawing (for what that is worth for a Ross) calls for .4620" right at the rim, and .4575" at .200" ahead of the rim. Their cartridge drawing calls for .4601" and .4554" respectively. Perhaps will have to machine a die or sacrifice a sizing die for an arbour press (no shell holder) and then figure out how to press it back out?
An option I would try is spinning a couple of thousand off the base and try them in your chamber. I would also try measuring the bases of your cases. I have the same problem. I measure my bases and anything under 0.450 will work. Some cases had to be put in my lathe for base reduction. You can use a hand drill and a small flat chainsaw file. Neck goes in the chuck. Low to medium speed and gently hold file against base. I do a fair bit of case forming of odd calibers so I have learned to to make cases fit.New brass may have the base small enough to chamber in your rifle. I have a five gallon bucket about half full so I usually just go through it and start measuring.
I ponied up and bought some virgin Hornady brass. Winchester stuff wouldn’t chamber. Hornady stuff is slightly tighter and chambers perfectly. Don’t know why I didn’t think of it before! I will have to file down my PPU brass if I want to use it though. Visibly larger at the base.
New brass from Winchester and PRVI don't fit?
No, Winchester would not chamber. Didn't have any virgin PRVI stuff to try, only once fired.
I have a similar problem with my Ross - all my full sized reloaded brass won't fit (I also use the Lee die set). Fortunately for me, factory Winchester brass (and a bunch of old surplus Greek boxer primed brass I bought) fit, so I separate my 303 into Enfield and Ross brass, then just neck size everything (range pick-up is always full-sized then goes into the Enfield box).
Strange that factory Winchester doesn't fit. I trust you've cleaned the chamber and slammed the bolt forward?
Guessing time to buy a bunch of different factory and see what chambers.
Strange that factory Winchester doesn't fit. I trust you've cleaned the chamber and slammed the bolt forward?
Guessing time to buy a bunch of different factory and see what chambers.I have a similar problem with my Ross - all my full sized reloaded brass won't fit (I also use the Lee die set). Fortunately for me, factory Winchester brass (and a bunch of old surplus Greek boxer primed brass I bought) fit, so I separate my 303 into Enfield and Ross brass, then just neck size everything (range pick-up is always full-sized then goes into the Enfield box).
Strange that factory Winchester doesn't fit. I trust you've cleaned the chamber and slammed the bolt forward?
Hornady works perfectly I have found. A bit pricey but I suppose I’ll just tell myself it is a target rifle and deserves the best
bdft
CGN Ultra frequent flyer
I was going through this exact problem last weekend. I ended up sitting down with a pile of brass, a Ross rifle, an original Mk 7 round to compare and calipers. I tried each round in the gun and ended up with about 30 that will be easy to reload. As I see it, there are three issues with brass in a Ross, the diameter at the base just above the rim and the diameter about .25" above the rim and the distance of the shoulder from the rim. A number of my Lee Enfields blow the shoulder slightly forward and balloon the cases a tiny bit. Many of these cases won't chamber in a Ross without some serious full length resizing. I'm going to try annealling some of them and resizing them back to factory specs. We'll see.
A friend of mine also mentioned a Hornady small base die as a possibility. Not sure how much difference it would provide compared to a Lee factory full length resize.
You might try removing the decapping assembly from the sizing die, and squeezing the case into the die in a vice and tapping it back out.
Use sufficient lube of course.
If successful, it only needs to be done once.
Back in the eighties, I had a snugly chambered Colt revolver and brass that had been fired in a sloppy Smith, and this solved the problem.
Use sufficient lube of course.
If successful, it only needs to be done once.
Back in the eighties, I had a snugly chambered Colt revolver and brass that had been fired in a sloppy Smith, and this solved the problem.
- Location
- Western Manitoba
The squeeze-in-a-vice idea will set back the shoulders on the 303 case, an 1/8" or more - no shoulders on the revolver cartridge, I presume.
bdft
CGN Ultra frequent flyer
Interesting idea. I might have to try that.
My II** Ross will not accept FL sized brass fired in a Lee Enfield. I made a die to size down the casing back toward the head. This works well. An option would be to start with new brass or ammunition, and reserve the cases for the rifle.
