284 Winchester Help

[Baily]

Hello everyone,
I need a little advise. I'm wanting to build a 284 Winchester but was wondering what the FPS would be out of a 26" barrel with 162 Amax. I'm guessing 2800 FPS. Like to use 4831sc if possible.Thanks

 

[TonyR]

Do a search on the user name "JHardy" on this site. He as posted some very detailed results

 

[Baily]

Thanks alot

 

[reubenski]

2800 is easily done with a 26" barrel. The question for me is 2950 attainable and accurate? An extra 150fps makes that combo extremely competitive.

I am using 53 grains of RL17 to hit 2850fps w/ 162 Amax's on top of CCI BR2 in Norma 6.5x284 brass in a 26" broughton with a 1:9 twist. I have gone faster but it is not as accurate. I have had chrono issues, but have used Atrag to proof the velocity. I need 4 mils at 600m. If Hornady's BC is correct, that puts me at 2850fps.

I am trying to work 2900 with 54.3grs. It is not as accurate and is close to high pressure,54.5+ or 55). I will start to play with seating depth and switching to Lapua brass. If I can't work that, then I'll rechamber to 284 Shehane, or completely swithc barrels to 284 Shehane in a 28".

 

[JHardy]

Rub:

Be careful with RL-17 in the 284. In my testing with the 284 Shehane, I had virtually no pressure signs until I blew a primer and smoked another. Sneeky stuff that RL-17. Now, I am waiting for a Hornady bullet puller to arrive.

Good luck and let us know how the RL-17 finishes up for you.

Jim Hardy

 

[Baily]

What is the neck diameter of a loaded round?

 

[TonyR]

My reamer gives a .313 chamber neck and I plan to turn for a .310 loaded round. I may adjust this with some experience.

 

[Baily]

Thanks. My Hornady 7Th edition reloading book has .320 . So does my Sierra book. But I did read on here that with a .312 bushing will give .002 neck tension.

 

[Rustystud]

The loading books all show .320 and .321 necks.

I am using 6.5 X .284 Lapua brass necked up to .284.

I size with a .313 bushing and my PT&G reamer cuts a .3166 neck.

I am shooting 180 Bergers w/52.0 H4831 in a 30" Broughton 1:9 5C.

Rustystud

 

[TonyR]

I never gave this any thought before because I knew I was going to turn the necks in any event, and I was going to get my own reamer. QuickDesign shows a .3201 CIP standard loaded round neck. The CIP standard chamber shows .322. I believe that these are specifications for maximum dimensions in factory guns. It must be because my virgin Lapua 6.5X284 brass usually measures on the low end of a .015 to .016 range before I turn it so, with the expansion to .284, the loaded neck would be .316 or less. I have some 6.5X284 Norma brass here somewhere that I know is heavier than the Lapua so perhaps those necks are thicker. I've never measured any Winchester brass. My gunsmith says to use .003 to .004 loaded round clearance in the chamber for maximum accuracy.

 

[heikki02003]

I also read to alow ample clearance on the neck; that tight neck chambers were hindering accuracy. This is to my advantage because I am ordering a reamer from PTG without sending in a dummy. Could someone provide a neck mic of a loaded round in unturned Winchester brass. I am sure Kiff could help me out, I'd just like to have some specs so I have a ballpark number when he's suggesting neck sizes.

I have the following reamer specs from this thread:
.3166 for Lapua
.3130 for turned necks
.322 CIP standard chamber

Any numbers for unturned Win brass?
Thanks

 

[FroggyOne2]

The loading books all show .320 and .321 necks.

I am using 6.5 X .284 Lapua brass necked up to .284.

I size with a .313 bushing and my PT&G reamer cuts a .3166 neck.

I am shooting 180 Bergers w/52.0 H4831 in a 30" Broughton 1:9 5C.

Rustystud

The reason that the loading books show that size neck is that the .284 was originally designed for a lever action rifle.. and they designed it that way for better feeding. Yes.. most Winchester brass that I had when I used to shoot the .284 would measure about .313 or so with a bullet seated.. so when I ordered my reamer.. I had it made with a .315 neck.. If you want a nice no neck turn chamber, have it made with a .315 neck.

 

[Baily]

I was wanting a no neck turn. This sound great. Thanks for the info.I had a hell of a time today finding 4831sc and CCI BR2 primer. But I got lucky and found some.All the local store are just out of everything.
Ok I'm going to start a new thread about chambering a die.If any of you guys can help just look for my new POST.Thanks