.284 Win barrel options?

I am thinking about ordering a barrel from X-caliber in .284 Win, just have a few questions that maybe someone could answer.

First, does anyone know what 284 chamber x-caliber uses? Im wanting to run a COAL of 2.950 with the 162gr ELD-X and im concerned that a SAMMI spec chamber will be a bit short, while a match chamber for Bergers will be on the long side.

Second, im up in the air on twist rate. Xcal offers 1:8 - 5r, 1:8 - 6 groove, 1:8.5 - 3 groove, 1:9 - 6 groove, and 1:10 - 6 groove. Hornady specifies 9.5 minimum. I have heard good things about the 5r rifling, but will 1:8 be too quick?

If anyone has some wisdom to impart on me it would be greatly appreciated.

I went with a CBI 260 Rem MATCH chamber... to shoot the 143 ELD-X bullet out of mine... Went with an 8 twist... My COAL is 2.933 (.02 off lands).... Not sure if that will help you at all, but you would want a MATCH chamber I would think.

The problem with a .284 match chamber (if my interweb research is correct), is that they are normally set up for 180gr Bergers in a long action with COAL's of 3.2" or more. Since im trying to work with my short action i would think that i would end up with way too much bullet jump. Thanks for the input SageRat, im learning as i go.

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Originally Posted by Esninak

The problem with a .284 match chamber (if my interweb research is correct), is that they are normally set up for 180gr Bergers in a long action with COAL's of 3.2" or more. Since im trying to work with my short action i would think that i would end up with way too much bullet jump. Thanks for the input SageRat, im learning as i go.

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I just went through the same thing and match chambers depend on company like CBI .220 where some were .185 .190
ssme concern building short action I decided on shelin with Sami specs as I talked it over with local gunsmith and if need be I could add throat the othe option is you can make a dummy round and send it to some of the barrel companies and they will customize it for you usually No Charge

So I just got an email back from Xcal with their reamer dimensions.

.284 Win - .322" Neck, .000 Freebore length, .290" Freebore Diameter, .578" Leade, .594" Throat

Can someone help me decipher this?

Quote:

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Originally Posted by Esninak

So I just got an email back from Xcal with their reamer dimensions.

.284 Win - .322" Neck, .000 Freebore length, .290" Freebore Diameter, .578" Leade, .594" Throat

Can someone help me decipher this?

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Sorry I couldn't be more help on the first post. My suggestion now is to send LoneWolf an email or PM (he is an X-caliber shooter) to see if he may be able to break down those dimensions for you. He's been helpful to me with my laundry list of questions over the course of my build.

Attachment 3965

So I found this drawing for a SAAMI spec reamer and it matches up with the dimensions I was given. They are measuring throats and leade from the end of the case mouth. And if I am understanding correctly the throats begins to tapper immediately after the case mouth, meaning that there is zero space to seat a bullet with an ogive beyond the case mouth.

I don't know... that doesn't give you very much "play" for bullet seating depths... I've found those ELD-X bullets to be pretty long. That 162gr. is 1.48" long.... my 143 gr. was 1.44" long.... I built mine on a LA... you're trying to stay with a SA... really think you will have to go with a Match chamber, otherwise you're really going to be cutting into your case capacity...

The Berger 180 gr. is 1.525" long so it's only .047" difference in length.

Good luck to you, I hope you find the reamer you're looking for.

Thanks again SageRat, i will keep looking around, start calling other barrel makers to see what they offer.

Bigbuckdn - i have read through your thread a few times, excited to see how your project comes together.

I'd check with Criterion or Shilen directly... As those 2 barrels are also really good. You may be able to just call James at Northland Shooter Supply and see if he has any recommendations for you... I've bot all of my CBI barrels through them.

Cheers,

I can't provide much help for your question #1.

For #2...mine is a 26" pipe 1:9 twist and it stabilizes the new 180 eldm just fine. Hornady recommends a 1:8. You're wanting to use 162's so a 1:9 should serve you well.

If you make 2 or 3 dummy rounds with the projectile of choice a competent smith or barrel chambering service should be able to accommodate you using your brass and projectile assembled to your specifications. Talk to AGW, Shillen or Bugholes or any other competent machinist. The barrel is the last thing you want to skimp on if you want real accuracy.