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6.5-284 Barrel Info Needed
crp
Member Posts: 12 ✭✭
I am looking to buy a barrel in 6.5-284. The gun will be used for whitetail deer hunting and possibly mule deer as well. My bullet selection would be 120gr. to 160gr. Would like to know which twist would be best for these bullets. Also, I have heard a lot about seating depth of the bullet,seems to be an issue with bullet contacting the groves. Would like to hand load to get the most out of the cartridge. Can the seating depth issue be resolved? If so how? Any thoughts on Barrel length for a hunting rig? Plan on building the gun as a single shot break open action. Any thoughts and advice would be greatly appreciated.
Comments
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Twist rate is based on the bullet length and not the bullet weight. Longer bullets (which are not necessarily heavier) need a faster twist to stabilize the bullet in flight. The standard twist rate for the 6.5mm cartridges is somewhere between 1:9" and 1:8" with the 1:9" being common for hunting weight soft point bullets. The 1:8" twist get use with the monometallic bullets like Barnes or other solids and the longer 140 gr. bullets including but not limited to the AMAX and VLD bullets.
Seating depth is based on the chamber leade and throat length. Longer bullets seated out need a little more leade and a longer throat. See below:
Seating bullets out gains more case capacity which can improve the number of useful powders that can be considered for your case/bullet combination. It can increase your flexibility with powder selection.
"...seems to be an issue with bullet contacting the groves."
It's only an issue if your load exceeds the proper pressure curve. If you start your testing with the bullet seated into the lands, you'll see when the pressure begins to rise and you can stop.
Bullets do not have to be seated into the lands if your chamber has been cut absolutely concentric with the bore line.
Normally, I select the bullets that I'm interested in using. Then I seat them individually in cases until the top of the boat tail is at the neck and shoulder junction. It's simple math. These are your chamber dummies and seating dummies. Glue these in place and have a conversation with gunsmith. If he doesn't understand throating reamers or doesn't have the proper reamer to accommodate your bullets when seated, get a new gunsmith. I use the 6.5x284 Norma as my standard because it has a longer throat. Remember though, too much variation between bullet lengths will result in some form of compromise. Be prepared to select which bullet is the primary concern.
Longer is better for barrel length and since you're using a break action single shot, even a 26" barrel will be acceptable for hunting without getting to be too long.
This is the short version, there's more but I'm out of time.
Best.
As always, nononsense's reply is spot on & correct as far as the caliber you picked is concerned.
I question the advisibility of putting a hi-pressure cartridge in a relitively weak-by-design break open action. The only such action I know of designed for higher pressure is the Thompson Encore.
Also, the rebated rim cases such as the 284 case is the most difficult to adapt to a single shot. The body of the 284 case being larger than the rim requires the extractor to move back to extract the casing then move down away from the centerline of the bore so the larger case body can pass.
Good luck on your 'build' Jim
Follow his advice...he has never send me in the wrong direction.
Best