reloading 303 British...partial neck sizing to creat another shoulder?

[Geofois]

I've read a bunch of discussions on the different ways to fire form and resize brass. There is the O-Ring method, partial full length sizing, and someone said expand the neck and then resize down but leave a shoulder. I didn't see any pics so I took my fired brass and just when 2/3 ish of the way down leaving a shoulder that seems like it would hold in the center of that part of the chamber. Has anyone done this? I'm going to test it out with some .312 150g Hornady bullets and some 308 bullets. My enfield shoots 308s at 100 yards in decent groups. I'll report back with the results.

[pacrat]

I've read a bunch of discussions on the different ways to fire form and resize brass. There is the O-Ring method, partial full length sizing, and someone said expand the neck and then resize down but leave a shoulder. I didn't see any pics so I took my fired brass and just when 2/3 ish of the way down leaving a shoulder that seems like it would hold in the center of that part of the chamber. Has anyone done this?
I'm going to test it out with some .312 150g Hornady bullets and some 308 bullets. My enfield shoots 308s at 100 yards in decent groups. I'll report back with the results.

Yes, I have. But not with 303 Smelly Limey. You already know I don't have one.

2/3's is a bit much. With 30-30, 7x30 Waters etc, and belted case guns. I just leave bout last 1/8" of neck unsized. It's circumferential alignment that counts. To align bullet to bore. And that's all that's needed. To snug the center of the case at the neck/shoulder juncture into the chamber neck CL.

[Geofois]

That makes sense. I loaded some up so I'll test out some groups and see. I have a scope on the No4 so it's a little less smelly than the earlier ones =P. I measured and looks like the bottom 1/3 of the neck comes close to 1/8". I should have said I sized 2/3 of the way down the neck. I use a 308 die to neck size and it seems to work great. It doesn't touch the sides of the case and is really smooth. Maybe I should invest in a Lee collet neck sizing die to reduce brass fatigue. The only problem is I think it only sizes necks for 311-312 Dia bullets. Mine shoots pretty well with 308s but if xmas has a decent sale and supply then I'll buy a bunch. I forgot to buy them when speer had their sale and rebate a couple months back. I bought 1000 30-30 bullets. Maybe I'll test it out Sunday. Thanks Pacrat. Hope all is well.

[pacrat]

That makes sense. I loaded some up so I'll test out some groups and see. I have a scope on the No4 so it's a little less smelly than the earlier ones =P. I measured and looks like the bottom 1/3 of the neck comes close to 1/8". I should have said I sized 2/3 of the way down the neck. I use a 308 die to neck size and it seems to work great. It doesn't touch the sides of the case and is really smooth. Maybe I should invest in a Lee collet neck sizing die to reduce brass fatigue. The only problem is I think it only sizes necks for 311-312 Dia bullets. Mine shoots pretty well with 308s but if xmas has a decent sale and supply then I'll buy a bunch. I forgot to buy them when speer had their sale and rebate a couple months back. I bought 1000 30-30 bullets. Maybe I'll test it out Sunday. Thanks Pacrat. Hope all is well.

We're hang'n Dude. Haven't forgotten you n your smelly's.

Check out this part. https://leeprecision.com/decap-mandrel-.3085.html I think it's what will fix the .308 issue. Pretty easy to chuck their mandrels in a drill or DP. Then use 400 wet sand paper with oil to dress them down for good neck tension. Might want to check with the Guffster on that tho. He's the ubiquitous "tensions" egg spurt.

I know I'm bad, couldn't resist.

Be well

[Geofois]

Awesome thank you. Hah

[walkonmars]

I also have a No.4 that is in so, so shape. It still shoots 308 bullets well. I just substituted the center mandrel from a 308 neck sizer into the 303 Brit neck sizer die. I have not tried to substitute full length sizer mandrels, yet. I get reasonable groups with 168 bullets over Hodgdon 4895. Using a scope rigged to special mount I get 3 MOA. I think the rifle is very tolerant to loads. I have experimented with 123, 143, 155, 168, and 180 grin bullets. The best groupings were from heavier bullets but I wanted to settle on one bullet for several rifles and purchased thousands of the 168grain HPBT so most of my data is with those. As I said, the rifle is very tolerant (at least mine is) and more importantly is to be sure the barrel is free from stock interference. Your SMLE have a more complicated barrel and stock interface so I can't comment much on it. Hope your results work out well.

[Geofois]

That's great. I used the 303 mandrel in my 308 sizer when I neck sized to try the .312 bullets. I have 3 308 mandrels. I think my 303 lee die set came with a 308 and a 311. When I measure the 308 it's like .3055 or .306 I think and the bigger one is like .309. I imagine you need .002 smaller to create decent tension. I have a collet crimp die but I never use that. I don't crimp my 308 or 223 either. The group at the top of the pic was my last group as I tested different bullets. You can see the variation of speed seemed to cause a vertical grouping. I'll compare tomorrow if Azusa isn't on fire still how my new loads work. Testing .312 hornady 150 grain vs 150 bt not hp with the exact same powder charge of H335, 42 grains. I'm going to chrono them both.