• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

284 win Reamer advice

MJT

Hi - I am new to 284 win. I currently have a 6 Dasher for F Class and love it, but on windy days I get clobbered past 700m, so I have decided to join the crowd and get a 284 win. I was advised to get my own reamer during our last match by several people. I honestly know nothing about reamers, and will certainly talk to the gunsmith about it, but wanted to get some advice.

Looking at using a Borden BRMXD action.

I would probably stick with Lapua brass and Berger bullets, and was thinking about using the 180 hybrid for the 284 win rifle. Any advice on which manufacturer to contact to purchase a reamer, which reamer etc is greatly appreciated.
 
If your going to shoot Berger 180 Hybrids get a reamer with .220 freebore. What ever neck size you choose a loaded round should have at least .004 clearance.
 
Talk to "shootsdot"here on the forum.He sent me to my/his gunsmith in Texas Thomas Holbrook43 here on the forum. You cannot ask for two nicer people . Tom is a Captain of a ship that services oil rigs in the Gulf and is working for the next two weeks. Thomas has had his hands full on my build but has totally kept me informed. He will continue to get my business,he's that good to work with. He built my 284 which is coming tomorrow. Contact Ben (Shootsdots).
 
I went with a JGS .316 neck and .225 freebore on my straight 284 build. I clean up the necks on Lapua brass to .014" thickness and that gives me .004 neck clearance. If I had to do over again, I may would stretch that freebore out a bit farther. I'm interested to hear what advice others give on this subject.
 
Cowtownup said:
I went with a JGS .316 neck and .225 freebore on my straight 284 build. I clean up the necks on Lapua brass to .014" thickness and that gives me .004 neck clearance. If I had to do over again, I may would stretch that freebore out a bit farther. I'm interested to hear what advice others give on this subject.
Click to expand...
I'm a little out of my league on the reamer stuff .. what does extending the freebore do for you? Is to allow for extra powder in the case? Just checked my brass, slightly turned it's at .15" thick.
 
Last edited:
I'm scared I would murder an explanation of freebore, so I'm hoping someone else jumps in and explains it so you can understand it.

I will try to help some though... if you add the bullet diameter (.284) to the neck thickness of the brass (.015) X 2 you will get your approximate loaded round diameter... in your case,

.284 + .015 + .015 = .314" loaded round

In order to not turn that brass and have at least .004 neck clearance you will need to spec your reamer to have a .318" neck (.314 loaded round + .004 clearance = .318" neck). I'm not sure but I think a lot of shooters prefer to do a total cleanup of the necks resulting in a .012-.014 neck wall thickness. Lets just say you cleaned up your necks to a .012 thickness...

.284 + .012 + .012 = .308" loaded round

If you plan to do that then you would need to spec a .312" neck to achieve the recommended .004 neck clearance.
 
Neck clearance and free bore are two different things. Cowtownup is talking about neck clearance, not free bore.
Free bore is basically the amount from end of case to the lands. Longer free bore lets you seat the bullet out longer to achieve more case capacity and keep the bearing surface/ boat tail juncture above the " doughnut" area.


Cowtownup said:
I'm scared I would murder an explanation of freebore, so I'm hoping someone else jumps in and explains it so you can understand it.

I will try to help some though... if you add the bullet diameter (.284) to the neck thickness of the brass (.015) X 2 you will get your approximate loaded round diameter... in your case,

.284 + .015 + .015 = .314" loaded round

In order to not turn that brass and have at least .004 neck clearance you will need to spec your reamer to have a .318" neck (.314 loaded round + .004 clearance = .318" neck). I'm not sure but I think a lot of shooters prefer to do a total cleanup of the necks resulting in a .012-.014 neck wall thickness. Lets just say you cleaned up your necks to a .012 thickness...

.284 + .012 + .012 = .308" loaded round

If you plan to do that then you would need to spec a .312" neck to achieve the recommended .004 neck clearance.
Click to expand...
 
I ended up going with a PT&G reamer, has a .317 neck, cases slightly turned (.312 loaded) and a .231 freebore, seems to shoot the 180target vld's and the 183 mk's pretty well, giving it a try this weekend down in Alliance, NE. for it's first 1000yrd match, we'll see how it does (or how I do) !
 
You must log in or register to reply here.

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Classified Ads

Forum statistics

Threads
165,402
Messages
2,194,672
Members
78,873
Latest member
jimi123

Share This Page

Back
Top