284 MAX

I started out wanting better performance from small frame AR Platform.... I decided to base it off the Grendel case (when I found one on ground at the range) .

I machined reamers , dies for a minimum taper , 40° Case and chambered a 14 twist 22" barrel and fitted ot to AR.

Was so impressed with performance and precision I built a long 7 twist for AR, again was impressed .... now I have 3 bolt barrels chambered and getting ready to chamber a 12 twist for a Ruger action. 

IMO is an awesome small cal rifle to chamber.

Forming brass is a pain but worth it IMO if one has an AR Platform and wants bolt guns for convenience of using same brass, dies etc.

I use Norma 22 or 6 PPC brass as it has largest capacity.  Just shy of 38 gr h2o

I'm sure some would say my loads are too high of pressure. Some cases have almost 20 reloads of 88 eldm @ 3000 fps.

load testing have pushed 88 to 3075 , 75 gr 3300, 53 gr 3900 40 gr to 4100. This is from 26" barrels.

If I was not invested in AR and only building bolt gun one of the BR offspring would be a better choice IMO

This being the my first 40° Case..... I will not build anything other than 40° design! 

The 284 wildcat I just put together is also a 40° and is like the 22 Grendel IMP ...AWESOME! 

On 7/23/2019 at 1:37 AM, Elwood said:

As I'm sure you're aware barrel life is determined by powder choice and how you use the rifle. H 4831SC would be the powder of choice for all three 7's that you mention. My prediction on barrel life is based on having used two .284's five Shehanes and one KMR. 

.284, 2000-2300 rounds

Shehane,  1600-1800

KMR,  1500

The KMR  barrel life is really just a prediction as (I hope) I'm only half way through the barrel life. The real plus for the KMR is that you can equal or surpass Shehane speeds using N165, this should take the barrel life beyond 1500 easily. Neither the .284 or Shehane  have the case capacity to get the full benefits of N165.

 

I know this is an old... thread  it very little info on 284 KMR.

Any info you could provide as far as case  capacity ,case dimensions  ,barrel life (I'm sure you "know" by now lol) and performance would be GREATLY appreciated! 

Thanks !