Barrel configuration for a .284 win.

[Norm]

Can someone give me an opinion on the best barrel length for a .284win for an F-Open rifle?
Also what COAL would you set the throat up to shoot 175 grain Sierra matchkings?
Thanks.

[bruce moulds]

norm,
30" finished and 0.200/0.213 freebore works well for all round use.
i personally feel that a parrelell profile barrel is a bit muzzle heavy for ideal balance on the bags, preferring a williamsport profile. others would disagree on this, and beat me.
keep safe,
bruce.

[IanP]

Norm, the trend is for longer barrels when using a 284W as you gain a little more velocity and the increased barrel weight reduces the recoil. I have tried barrel lenghts from 30" to 32" and favour the longer heavier 32" barrels.

I use a slightly modded 284W case (Shehane) but the freebore I use for the 180gr Berger Vlds is 0.190". I like the boat tail of the projectile starting at the neck shoulder junction. I like the bullet seated fully on the bearing surface whereas many prefer it further forward.

I prefer a parallel 1.25", 5R barrel and at 32" long it gets my rifle close to the max allowed 10kg weight limit. The 32" length allows velocities with AR2213SC of 2930fps without destroying the brass with head expansion. I have not experienced balance problems and my rifle rides the front rest and rear sandbag smoothly.

The 284W case when loaded up too high will show pressure problems at the case head. Loose primers and cases that feel tight going into the shell holder are a sign that the load has exceeded the case's designed limits. The 284W is a great choice and pretty easy to find an accuracy node. Its also very easy to overload the cases and destroy the brass in a couple of firings with a hot load.

The 7mm RSAUM, another popular F-Class choice has the case capacity to need only a 30" barrel and still obtain high velocities with 180gr bullets. Its worth considering as the cases are designed for higher pressure and if you want 3000fps with the powder of your choice this may be a better tool to use than the 284W.

Ian

[DaveMc]

Plus 1 for Ians comments -

At recent state teams and Queens events there have been more and more 284's (or improved) and most have straight taper or Heavy Varmint profiles 30-32 inch. Talking around it seems standard Freebore seems to be 180-220 thou and this suits SMK (175 and 180) as well as Bergers.

[bartman007]

Norm,

At the recent Teams and NQRA Queens events, a few of us in the Vic team felt that it was horses for courses.

If you are looking for a short range caliber, I'd suggest that the 7mm may not be the most accurate. I'd run a 6mm or 6.5mm.

As for long range, I'd suggest that the 284W (including shehane) or Magnum chambering would be appropriate.

As for weight, I am at 9.655 Kg with a Nightforce scope and straight profile barrel, and bedding block. So you can manage the weight OK, and it helps greatly in rifle stability with the heavier projies and loads!

Cheers.

[Norm]

Thanks Chaps,

I picked up my new F-Open build recently and have just managed to find the time to start playing with it.

It looks like my set up will be slightly different to most people shooting the .284 win. I have a shorter barrel of about 28" and my freebore seems to be quite long compared to what most are using. The barrel is quite heavy although not a straight taper. The rifle weighs in at just over 18 lbs.

Be interesting to see how it goes once I have completed my load development. I initially run the barrel in with 168 grain SMK's and have just switched to the 175 grain SMK's to fire form some brass and work up a load using 2213sc.

This is my first purpose built F-Open rifle so will treat it as a learning exercise...............Thanks.

[bruce moulds]

norm,
don't rule out 2209 in that barrel either.
for 175/180 bullets there will be a node between 50 & 53 gn, although 53 is getting towards warm in most barrels.
bart,
sounds like you are already starting the sledging and misinformation working towards the next state teams in tazzy. you and alan obviously have a cunning plan afoot.
what has teams come to when mind games are a necessity.
keep safe,
bruce.

[bartman007]

sounds like you are already starting the sledging and misinformation working towards the next state teams in tazzy. you and alan obviously have a cunning plan afoot.
what has teams come to when mind games are a necessity.

Alas it didn't get us the number 1 placing this time round. The SA boys really had the goods.

As for down down under, we will need to work harder in 2014 as the conditions there I believe are in line with that of the Lower Light range.

Further advantaging the SA boys.

As for 2209, I currently have switched to it, and I think it is slightly more consistent. But still not startling! I'm going to try other projies and see if I can get one to sing. If not, I'll ream it out fatter

[bruce moulds]

bart,
i am on the cusp of trying 2217 in my std 284.
when time permits the chronograph will be called into play.
it is said to be too slow for this case, but a try won't hurt.
it seems to work ok in the 280 ackley.
re 17 is always worth a sniff. i had good results with it in one barrel, and speeds were up as predicted by the pundits. there are all sorts of rumours regarding this powder, but i have never actually met anyone who can prove or disprove any of them from actual experience, other than that it does give improved speed.
keep safe,
bruce.

[Hangfire]

Norm, have just weighed 2 X 7mm barrel blanks.

1 X 32” 1.25”- 1” profile = 4.47kg

1X 32” 1.25 parallel = 4.93kg (580grm/100mm)

This may help in ordering for length if weight is an issue.

[RAVEN]

Bart I had great result with my first 284 with 168Gr Berger’s
I have re-chambered that barrel 3 times and if I do my part right it is still good enough to win a badge here and there.