Thread: 284 win slow speeds

Originally Posted by Hunty1

Been flip-flopping about a 284win win build but my 20" 7mm08 tikka does 2630fps with 162gr ELD-M without leaning on it too hard. Doesn't seem like much gain for the hassle.

An extra 200fps is definitely worth it, just got to use the right powders. If you only want to shoot to 500 yards then I agree the 708 with short bbl will do the job nicely

Originally Posted by No.3

Are you running a muzzle break or a suppressor with it?

I am running a suppressor on it

Originally Posted by GWH

@Jim356

.317 neck on the reamer i see, was that the gunworks reamer?

You say a loaded round measues .314 neck dia, what is the dia if you move the calipers down closer to the neck shoulder junction? 284 is pretty fussy on neck clearance, and while it appears you have 3 thou total neck clearance, thats the bare minimum i reckon, and im picking down towards the shoulder you may not have that much.

Yes gunworks did the reaming. From what I can tell when measuring the brass it does seem to be just a fraction wider at the very base of the neck. What did you find to be the ideal neck clearance with your 284 @GWH?

Originally Posted by Marty Henry

@Micky Duck It always amuses me a bit when there's a post about disappointing velocity along with " I've had the barrel cut down to xx" Doing this with a cartridge optimized for a 22 or longer barrel seems like cutting the nuts off your prize huntaway and expecting his bark to deepen.

post of the month.....

There is 154ssts and 150eldx @ gunworks. I ran the ssts and got 2750 easily with 2209 and a 19" 284. Those bondstrikes are a bit harder so need a bit of speed

Originally Posted by Jim356

Yes gunworks did the reaming. From what I can tell when measuring the brass it does seem to be just a fraction wider at the very base of the neck. What did you find to be the ideal neck clearance with your 284 @GWH?

In the early days of 284 popularity in F Class the Yanks said the 284 likes "good" clearance. I could never work out how a cartridge could have the intelligence to know it needed good clearance. Obviously with good clearance there is some safety but you are also working your brass a lot more.

In all likelihood with springback your throat is probably .315. Did you get a copy of the reamer drawing? I always request that of the Smith. That gives me information for neck turning etc.

If you are using bushing dies the neck at the neck shoulder junction will always be larger due to bushing dies generally not sizing that far down plus the chamfer present on the bush.

I run mine at 2640, was just a load I threw together and it grouped well so used it and haven't bothered doing any further development. Shot a big stag at just over 500, that's the longest shot on game with it, decent nber in the 400 range and most others I the 2-300 with a few up close and personal. All with 162gr, never had to worry about over expansion up close and does well to the 500 mark which is my self imposed limit on game.

My first lot of up sized brass gave me pressure issues and I then found I had an internal donut, a relief cut with neck turner at the neck/shoulder junction prevented that happening in New lot of brass and removed the pressure issue. If you are using sized up brass and getting slightly thicker measurements at the junction it might be worth having a feel inside for donuts

Originally Posted by stagstalker

Those results look about right for the powders used. In my old 17” barrel with 162s I got 2600 with 2209 (H4350) at 53 - 53.5gr. I got roughly 100fps more with Rel17 (2700fps). I also experienced different pressure tolerances with different projectiles. For example the 162 X would hit pressure sooner then the 162 M did.

Others have had good success with H414 and Superformance too.
I just ran mine at 2600 with the 2209 and it was deadly.

Good advice.
ELD-X jackets are harder than the ELD-M, so are harder to engage with the lands, which can push pressure up a bit. Best to load a grain or two lower than normal with them.

Originally Posted by Jim356

Yes gunworks did the reaming. From what I can tell when measuring the brass it does seem to be just a fraction wider at the very base of the neck. What did you find to be the ideal neck clearance with your 284 @GWH?

That Gunworks reamer, if the same one, does have a .317 dia on the neck, it also has different lead angles than normal i believe, I remember Robbie telling me about it at the time.

I found that 3 thou total wasnt enough. I also found the neck to be wider at the bottom of the neck, by the shoulder junction, a neck turn to increase clearance, and make sure that it cuts down into the shoulder a little prevented donuts at the neck/shoulder junction and stopped me seeing pressure signs at lower powder changes than expected.

I think im at 5-6 thou clearance, and it was much happier.

I might give neck turing a shot at some point to see in the near future to see if I get any performance increases. Thanks for the information GWH

Originally Posted by Hunty1

Been flip-flopping about a 284win win build but my 20" 7mm08 tikka does 2630fps with 162gr ELD-M without leaning on it too hard. Doesn't seem like much gain for the hassle.

Why I rebarreled my 18inch 284.
Just couldn't justify the extra powder for a few extra fps.
When my 18inch 7mm08 was good enough to harvest deer at 500meters with the 162gr Amax.
So while the 7mm08 is now a 25 inch 7mmcreed the 284 is a 18inch 7mm creed and is currently throwing the 130gr speer @2750 during fireforming and break in