Ross 303 HG with "small chamber" and reloads

wasa

wasa

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Greetings. Not sure if this would be better in the reloading section but thought I'd try here first.

Previously, I posted about my WWI M-10 Ross Rifle (Home Guard) that I had never fired. Please see https://www.canadiangunnutz.com/forum/showthread.php/1689781-Request-info-and-links-on-Sporterized-Ross-M-10-(now-with-Pics!) for pics and details.

Decided I wanted to fire it, and based on previous posts, didn't want to shoot corrosive surplus ammo through it so I hand loaded a bunch of low pressure rounds using a Lee 3 set die system and ~12 gr Trailboss (once fired brass through my Lee Enfield). Took it to the range, and none of my reloads would chamber.

Going back to my original post, user jtaylor said "Your Ross has the small chamber that produced so much aggravation to our troops during WW1. The Ross problem was that Brit ammo had higher variances within different manufactures resulting in feeding jams usually. So make sure your bolt has fully closed on each cartridge you shoot and you should be fine."

And YES, this is my problem. I pulled the bullet from one of my corrosive rounds (dumped the powder, popped the primer) and the brass chambers fine. Did the same thing to a factory Winchester round with the same results (yay!). But, no matter how I adjust my Lee resizing die, I cannot take once-fired brass and have it chamber in this Ross. It would appear that the SAMMI diameter of 0.455" near the rim is too big for this Ross, and I need 0.451 or 0.452" (sorry - going from memory here on the exact numbers).

Google taught me about "small base" dies by RCBS but they don't make one in 303 (AFAIK).

Other than only shooting factory ammo, or making my own from factory brass (after pulling bullets and making new low pressure rounds) does anyone have suggestions on how to reload my own ammo for this 303 Ross?

Thanks!
 
I have had the same experience. Most .303" sizers are made to accommodate the large chambers used in SMLE and No4s. Brass fired in LE chambers will not be sized enough for the tight Ross chambers. I by chance acquired an RCBS die that will size LE fired brass enough but I believe it was made using a worn reamer.
Segregate fired cases from the Ross and use only in the Ross.
 
Wasa:
Trivia:
It's a MKIII not an M-10.
MUCH confusion as Ross used receivers with the "M-10" and "Model 1910 markings on both the militaries and sporters.
So it has evolved over the years, that the sporters are referred to as "M-10s" and the militaries as "MKIII" (model of 1910).
A 1905 prototype (post 5*) with many (more) improvements and an Enfield type stock (I have a bolt only) was originally called the MKIII at the factory (PP 124 RRS), as Ross and the military were becoming increasingly more embarrassed by all the *s on the '05s.
However, it never went into production, so the designation fell to the military model of 1910.
Just for fun.
OGC
 
Cases previously fired in a Lee Enfield and subsequently FL sized are unlikely to chamber in an original Ross chamber.
You would need the equivalent of a small base die.
I made a die to reduce the diameter of Lee Enfield fired brass just in front of the rim, so that he cases would work in my II** target rifle.
Easiest solution is to simply use new brass and not bother with cases fired in Lee Enfields.
 
Thanks for the info! Oldguncrank provides a fair point about M-10 vs Model 10 vs MKIII. Curious as to the logic of the Ross Company in stamping the receiver "M-10" (see pic https://i.imgur.com/8hk0NWS.png ) It says Ross Rifle Co Canada M-10 Patented so definitely blaming Ross for my confusion.

I'm liking the logic of keeping Ross fired brass separate from Lee Enfield fired brass. I have a factory box of Winchester ammo that chambers - will keep those separate for Ross-only. Thanks for suggesting it - I should have thought of that myself! (not enough coffee?)
 
The reason I made the custom die is that I had a couple of sandbags of once fired in Lee Enfields .303 brass.
Incidentally, the cull rate was close to 20% for incipient case separations. Be cautious with pick up brass fired in LE rifles.
There is nothing wrong with the original dimensions of original Ross chambers - as long a decent quality ammunition is used. LE chamber specs were changed as well. This is why so much sizing happens when LE brass is put through a FL die. Compare unfired with fired with FL sized.
 
When I see a problem shared here I ask myself "What would I do?"

If my die did not size the brass enough to chamber in my Ross, I would ask my buddies who have a 303 BR die to lend me theirs, to see if that would work.

If it did, I would then fire a few of those sized cases and see if my original die would now be adequate.

If it did not work, I would offer to trade dies with the the lender, because his die is clearly over working his brass for hos lee Enfield, and I am always willing to help a friend...
 
You may have to shoot factory ammo in it,only neck size it and keep it separate from the L.E brass.

My Ross has a large chamber and in order to avoid case head separations I only neck size the brass with a LEE collet neck sizing die.
 
I use new brass and neck size only for each of rifles in 303. I have a Ross homeguard as well.

When I figure I'm at there last firing the go to my jungle carbine . It has the largest chamber out all my rifles.

If you decide to try a faster load I'm getting very good results with 180 Sierra bullet and 37 grains of IMR 4895. Amazing groups with an iron sight rifle. Still a mild load.
 
Fire new in the Ross, keep the brass separated and neck size it for use in the Ross only. Try to find some Prvi Partisan 303 - the brass is excellent for reloading.
 
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