Freebore on .284 Win

[ChrisNam]

I currently shoot F Class with a straight .284 Win using 168gr Bergers/SMK’s in front of a local powder to get 3020 fps.

Some time ago I ordered,and received) a .284 Win reamer from Pacific Tools with a freebore of .120. A friend of mine has already chambered his barrel with this reamer and I also now want to chamber a new barrel.

A couple of other shooters however advised me that the freebore of .120 is too short for the 168gr Bergers/SMK’s. It is indeed so that the freebore of the previous barrels seems to be longer than .120, but obviously this does not mean that a freebore of .120 is too short.

My question is: what is at the ideal freebore for the 168gr Bergers/SMK’s in .284 Win?

I will greatly appreciate any advice.

 

[expiper]

How do they seat in your friends chamber....if you have a chamber there that has been done with that reamer ...where are the bullets being seated to in realation to the donut,neck shoulder ) ...how much shank is in the case neck.??? You or he shuld be able to take some measurements and find out....I am curious tooooo.....Thanks for any and all info.....Roger

 

[FroggyOne2]

I would talk to Kiff and see about what would be the correct freebore for Cauterucio 190's or the Berger 180's. You could still shoot the 168's, but those bigger bullets work really well at 1K

 

[ronemus]

You won't want much more freebore or you won't be able to chase the lands as the throat erodes. My .284 started with that much freebore, and it put the shank of a 162 gr A-Max ahead of the neck/shoulder junction and the base a bit below; with the plastic tip, the A-Max is probably close to the same length as the bullets you're interested in.

 

[Bosveldklong]

Hi Chris,

What local powder do you use? S365 or S385?
What grain do you load for the 168 and what is your group size on 100m?

Frans Snyman
South-Africa

 

[dsbw]

Frans

I am the "friend" that Chris is referring to in his post. I am shooting 168gr Berger, S385 57gr, Bartlein 9.5 twist 29" finished, just on 3040 fps. Group size is still way off compared to previous rifle,Chris v Niekerk Tombi MK1, for the US readers, this is a locally designed 7 x 57 improved wildcat), I am currently looking at 10mm to 15mm group size.

I read that you are shooting 180gr JLK's? Are they locally available? If so, where can I find some, I'd really like to give them a run.

Dawie Blaauw

 

[ChrisNam]

I currently shoot the 168gr Berger in front of either 58gr S385,3030fps) or 53gr S365,2980fps) out of a 28" Krieger 1:10 barrel. The S385 group the best,6-8mm), while the S365 have the best extreme spread over a chrony. I mostly use S 385.

Both guys currently shooting barrels chambered with the .120 freebore reamer complains about accuracy and I further think the .120 freebore will result in a doughnut.

Dave Kiff has since advised me that most US shooters use a .180 freebore for the 168gr Bergers/SMK's. Seems as if he confused a 6.5x284 with the 284 Win when he suggested a freebore of .120. He has a hand uni-throater with a .188 freebore available, but I'm very cautious now. In my opinion, most US shooters using a 284 Win will use a 1:9 barrel to shoot the 180gr VLD's - I have not really heard about competitive US shooters using the 168 VLD's, although I may be wrong. If a freebore of .180/8 is used for the 168gr VLD's, what freebore is ideal for the 180gr VLD's?

 

[DMAC67]

Hey Chris,

Thought I would jump in here as I have a .284 and I am shooting both the 168 and 180 berger VLD's. I have a 31" Brux barrel 1.250" straight with a 1-9" twist. Mounted on a Barnard P in a Mastin F-class stock.

I had the same discussion with Dave Kiff regarding throat depth and the bullets I wanted to use. First let me say, I put this barrel together to have an advantage over a 6.5mmx284 with 140 Bergers. This would mean shooting a 180 VLD at 2800-2850fps. I did however have 1000 Berger 168 VLD's from a previous 7mm rifle that I did want to be able to shoot. So David reccommended the .188 freebore.

With the above freebore,.188) the 180gn Bergers have the bearing surface up in the neck with the boattail down past the shoulder. the 168 Bergers are a little further out but still have plenty of bearing surface in the neck with enough to chase the lands as they move forward. Keep in mind the lands should not be moving much at all or very quickly, this is a very efficient cartridge.

My rifle will shoot both the 168 and 180 Berger VLD's into 1 inch or less 10 shot groups at 300 yards and both bullets hold verticle well inside the 10 ring on the FC-LR target.

Hope that helps

 

[ChrisNam]

DMAC, thank you very much for the advice. I would like to ask you a couple of questions if you do not mind.

1. Will a 30" Bartlein 1:9.5 barrel, in your opinion, stabilize the 180gr Berger?

2. If I decide to only shoot the 168gr Bergers, again in your opinion and based on your observations with the said bullet, would you go for a slightly shorter freebore, say .160 or .170?

I really appreciate your help.

 

[JERRYHM]

Reamer print that we use for the Berger 180s and Sierra 175s.
Barrels are Krieger 30" 1:8.5.

 

[ChrisNam]

Jerry
Thank you very much for posting the print. I'm however a bit confused by all the data - what is the freebore on the print?
Thank you again.

 

[rcw3]

The free bore is dimension "U & V" on the print which is .175" on this print.

Robert Whitley

 

[Kurt Blasser]

Hey Chris,

Thought I would jump in here as I have a .284 and I am shooting both the 168 and 180 berger VLD's. I have a 31" Brux barrel 1.250" straight with a 1-9" twist. Mounted on a Barnard P in a Mastin F-class stock.

I had the same discussion with Dave Kiff regarding throat depth and the bullets I wanted to use. First let me say, I put this barrel together to have an advantage over a 6.5mmx284 with 140 Bergers. This would mean shooting a 180 VLD at 2800-2850fps. I did however have 1000 Berger 168 VLD's from a previous 7mm rifle that I did want to be able to shoot. So David reccommended the .188 freebore.

With the above freebore,.188) the 180gn Bergers have the bearing surface up in the neck with the boattail down past the shoulder. the 168 Bergers are a little further out but still have plenty of bearing surface in the neck with enough to chase the lands as they move forward. Keep in mind the lands should not be moving much at all or very quickly, this is a very efficient cartridge.

My rifle will shoot both the 168 and 180 Berger VLD's into 1 inch or less 10 shot groups at 300 yards and both bullets hold verticle well inside the 10 ring on the FC-LR target.

Hope that helps

Will a freebore of .220 allow shooting the Berger 180 VLD or the Berger 180 Hybrid? Looks like the bullet is pushed in pretty far with boat tail below shoulder by a little. Anyone shooting 180 VLD's with 220 freebore. I could use a COAL.

 

[FeMan]

This thread is pushing 11 years old!! Not sure how many of these guys are around here anymore.

I use a 0.235 freebore. I'm on my 5th barrel and it has been perfect with everything I have fed it, except 180 ELDMs (these need closer to 0.250 or more freebore IMO). If using Lapua brass, you need to watch donuts. The 0.220 might be fine but I would opt for a little more room. My best load to date was with 180 Hybrids and that barrel liked 0.054" jump. My spread in jump has been 20 to 50+ thousandths.