Thread: 284 win getting low velocities

GWH
The fired neck was about .313 and about .311 with bullet seated. Its hard to get an accurate reading measuring the top of the shoulder as it is hard to see weather its ment to be the shoulder taper or not towards the neck. It does.increase slightly so maybe neck turning will help drop the pressure.

In response to the discussion about the need for neck turning, -presumably the only reason to do this is if you get pressure signs with loads that are well under what should be a maximum load?

I have a 16” 284 which I am struggling to get decent velocities from. Currently up to 55g of 2209 with a 140g Sierra GK and only getting 2650. Super-accurate and no pressure signs but seems to be a lot of powder for modest velocity. My 23” 7mm08 gets more speed with the same projectiles and only 41g of 2208. Am not completely confident in my chrono but even with a bit of error it is still slow. Will try re17 next.

Originally Posted by stevodog

Hey GWH, did your right neck affect pressure/velocity? Did you have trouble chambering them before neck turning?

Yes i got excess pressure signs (heavy bolt and case head stamping) at very low powder loads. Once i turned the necks right down into the shoulder i could then run a more normal (higher) powder load and sure enough increased velocity without seeing the excess pressure.

Originally Posted by rossm-96

In response to the discussion about the need for neck turning, -presumably the only reason to do this is if you get pressure signs with loads that are well under what should be a maximum load?

I have a 16” 284 which I am struggling to get decent velocities from. Currently up to 55g of 2209 with a 140g Sierra GK and only getting 2650. Super-accurate and no pressure signs but seems to be a lot of powder for modest velocity. My 23” 7mm08 gets more speed with the same projectiles and only 41g of 2208. Am not completely confident in my chrono but even with a bit of error it is still slow. Will try re17 next.

man this one is really a case of trying to reinvent the wheel isnt it...... guys have used longer barreled rifles with run of mill cartridges for ....well for ever to keep velocity high.remember fellas used .303 with full length barrels to do some rather long shots back in the day...not the ones that had been cut down for bush work.
you can go so far by changing case...but only so far....
guess its a bit like changing motor and tyres on a car but leaving gearbox the same.....

Originally Posted by c-dog

GWH
The fired neck was about .313 and about .311 with bullet seated. Its hard to get an accurate reading measuring the top of the shoulder as it is hard to see weather its ment to be the shoulder taper or not towards the neck. It does.increase slightly so maybe neck turning will help drop the pressure.

Is that .313 on a fired case neck before resizing, if so you have an extremerly tight chamber, like a very tight match chamber. Might pay to re-measure.

Originally Posted by rossm-96

In response to the discussion about the need for neck turning, -presumably the only reason to do this is if you get pressure signs with loads that are well under what should be a maximum load?

I have a 16” 284 which I am struggling to get decent velocities from. Currently up to 55g of 2209 with a 140g Sierra GK and only getting 2650. Super-accurate and no pressure signs but seems to be a lot of powder for modest velocity. My 23” 7mm08 gets more speed with the same projectiles and only 41g of 2208. Am not completely confident in my chrono but even with a bit of error it is still slow. Will try re17 next.

That is very slow, im at 2700 fps with the 162 Amax in my 17" 284 with 52.5gr of H414. And have run up to 54gr of 2209 with the 162 amax.

Great thread...hope you guys get your 284s cooking soon. Thanks for the schooling on neck size and turning GWH.
The necks on mine are even through to the shoulder at 0.3230 so I guess I can rest my wee brain now.
Out of interest, what neck turning gear are you using?

So unless requested otherwise, why don't gunsmiths do .284 chambering with bog standard not shit and ordinary reamers that match ordinary off the shelf dies?

Originally Posted by Tahr

So unless requested otherwise, why don't gunsmiths do .284 chambering with bog standard not shit and ordinary reamers that match ordinary off the shelf dies?

AS far as im aware they do, when i found out the smith had two reamers (saami spec .321 and the tighter neck of .317) i opted for the .317, as over the years the 284 brass has got thinner on the necks for some reason, and i notice on my other 284 with the .321 neck that the necks get over worked alot fire forming all the way out from .313 to .321 and ive had some split the necks, annealing obviously helps.

So i thought id go with the tighter necked reamer to work in better with the brass that's available today. There is also a different in the 'lead' of that reamer to i believe.

I was told that they cut different chambers for modern bolt action rifles vs the older lever actions that the 284 was designed for. Not sure if that explains why some bolt action chambers are cut so tight.

Thx for all the replies to my earlier questions.

Originally Posted by rossm-96

In response to the discussion about the need for neck turning, -presumably the only reason to do this is if you get pressure signs with loads that are well under what should be a maximum load?

I have a 16” 284 which I am struggling to get decent velocities from. Currently up to 55g of 2209 with a 140g Sierra GK and only getting 2650. Super-accurate and no pressure signs but seems to be a lot of powder for modest velocity. My 23” 7mm08 gets more speed with the same projectiles and only 41g of 2208. Am not completely confident in my chrono but even with a bit of error it is still slow. Will try re17 next.

Yeah that seems super slow. I'm at 2750 in a 19 inch Barrel with the 162's and 52.7 414. 55gr 2209 sounds light behind a 140. Maybe stoke her up a bit.

Adi lists max load for 2209 and a 140 as 57 gr. They have it as a compresed load. Maybe try 2208 or go to a heavier projectile get that pressure up a bit. Will be shooting alot of unburnt powder out the end with that 2209 load.

The 284 is best with 150gr plus imo

Thx Nick. That max load data from the adi website is different to my nick Harvey book which lists the max for 140g prom with 2209 as 54.5.will have to use the adi data in the future.

Anyway have loaded some 150g Sierra GK’s with Re17 to see how that goes. I am still wary that my cheap chronograph is under- reading but can’t be more than 50-100 FPS.

Cheers Ross

Originally Posted by rossm-96

Thx Nick. That max load data from the adi website is different to my nick Harvey book which lists the max for 140g prom with 2209 as 54.5.will have to use the adi data in the future.

Anyway have loaded some 150g Sierra GK’s with Re17 to see how that goes. I am still wary that my cheap chronograph is under- reading but can’t be more than 50-100 FPS.

Cheers Ross

Yeah the 150's over rl17 will get things humming. Fella on the other forum getting 2900ish with the same load

Originally Posted by Nick-D

Adi lists max load for 2209 and a 140 as 57 gr. They have it as a compresed load. Maybe try 2208 or go to a heavier projectile get that pressure up a bit. Will be shooting alot of unburnt powder out the end with that 2209 load.

The 284 is best with 150gr plus imo

That's the exact load I get. I could go a bit faster, but this was best accuracy wise that I was happy with. 57gr or 2209 gives me 3040fps out of a 19.5 inch barrel using a 140gn Berger VLD Hunting..

I had pressure at low speeds on mine, was getting an internal donut at the neck/shoulder junction, neck turn and cut slight relief into this area to let brass flow into void and prevent buildup on inside. Been a couple of guys on here with same issue and same fix