22-284 Winchester cartridge development



“The next trip out to the range was sunny and a balmy 45 degrees, pet load of H1000 @ 53grains and this time 230yard groups printed ½” for 3 shots! Yes I was really happy! ”









22-284 Winchester,  Life at 40X


After a recent varmint rifle build using the 284 Winchester case (TVHA issue 84) I made a mention that a barrel was on order for a 22-284 Winchester chambering.  This article will focus on the cartridge and load development along with a field test on the Barska Benchmark 40X scope.

Many hours have been spent reading thru older publications regarding the 22-284 and searching web forums for load information.  There is not a lot of info on this cartridge as most shooters just write it off as an extreme overbore with diminished returns on powder burnt, along with short barrel life. To my delight I found an old forum thread that mentioned a 22-284 project back in the 60’s, once I gathered some bits and pieces on the article I found that it was a “Guns & Ammo magazine” August 1964 issue titled “ 6000fps world’s hottest .22!  by Bob Hutton “.  I did a search on e-bay for the old Guns & Ammo 1964 issue and for $7.00 shipped it now resides in my reloading library.  Reading the article makes one envious of the developers of that era, as mentioned in the article regarding velocities of 6585fps and showing some cartridge high pressure signs. Then slowing things down a bit to 220 swift pressures clocking in at 6300fps!  All while keeping good 300 yard accuracy. Since 1963 when this .284 cartridge was introduced wildcatters have necked it from 6mm to .35 caliber with good results. I have kept a file with several pages of various loads used by past developers and decided to start with H1000 and Reloader 22.  With a 1-9 twist in this barrel I started out with 75 grain A-Max bullets loaded with a seating depth of one bullet diameter (.224”).  A dummy cartridge was seated with a 75grain A-max and checked for proper chambering, extraction and ejection. All went very well and I must say that is one impressive looking hot rod cartridge! I even think the crows outside kept quiet while I admired the round by the window thinking about down range performance.


Starting with a new barrel ordered from M&L Enterprise in Oregon, short chambered in 22-284 Winchester, varmint tapper, stainless steel, finished at 27” long.   The crown was cut to an 11 degree target contour then a PTG reamer and gauges finished the headspaceing to the action. With this miniscule .224 bullet being pushed with a very large amount of powder I chose to have the barrel cryogenically frozen (300 Below, inc) to help slow the unavoidable throat erosion.  Since this was a new barrel any accuracy improvement due to the cryo treatment cannot be confirmed however talking to several shooters boosted my confidence in the benefits of the process, so off it went to the deep freeze! With new 284 Winchester brass I start with a RCBS group G shell holder # 03, a form die that will size the case to a 6.5mm neck ( RCBS # 58119   ), as I found with my 6mm-284 project after necking down to 6mm the necks will need to be turned to a .014” thickness for best performance. Now with 60 cases formed to 6.5mm-284 it only takes a run thru a 6mm-284 full length die then a 22-284 full length die       ( RCBS # 56052 ) to finish up the forming.  Imperial sizing die wax was used during every step of the forming to avoid any crushed shoulders or necks, then primer flash holes are cleaned up, cases are trimmed to a uniform length of 2.1700” and finally necks/shoulder are annealed to eliminate any brass hardening from the forming process while necking down .284 to .224”.  Since I had such great results with Federal 215 Magnum primers to ignite the large quantity of powder in the 6mm-284 load during the development stage of the previous build. I decided to stay with them while load testing the 22-284.

 Note;  The mag primer tip was found right here on the VHA forum during a discussion with “300win”



Range time; with three different powder load charges of each H1000 and RL22 the first 50 yard zero checking rounds printed a nice tight ¼” 3 shot group with the fourth shop opening it up to ½”. That was with a new bore and H1000 @ 53 grains clocking in at 3468 fps. That’s good speed with acceptable 50 yard accuracy, now to do some 100 yard load development!

H1000 was tested first with 53, 54 and 55grains, again the 53grain load printed a ¼” 3 shot group with 54 & 55grains around the ½” mark and a top speed of 3579fps @ 55grains with a slight stiff bolt lift.  Now for the RL22 loads of 48, 49 and 50grains, consistent two shot one hole groups with one shot opening the group to ½”.  Speeds with RL22 ran close to 200fps slower than the H1000 loads, top speed with RL22 @ 50grains clocked in at 3331fps. Later that day studying the targets a pattern was easy to spot.  Since this was a new barrel I was cleaning the fouling and copper out after each shot, two in one hole with a flyer again and again! The flyer was the fouler shot, it had to be.  I was firmly rested in sand bags just touching off the 6oz Jard trigger and the 36X scope was equipped with a “Tucker” style reticule lock.  Wanting the speed for good varmint work I stayed with the H1000 and returned to the range to further test the 53grain load. I also had a 55.5grain load to check for more possibilities.  I was now cleaning the barrel after 3 shot strings and using some liquid graphite Lock-eez to coat the barrel with; ¼” groups became the norm with 53grains of H1000 and the 55.5grain load needed to be checked for its secrets.  Remember what you read I told myself after touching off one round and then needing to really pry hard on the bolt handle to extract the round!  You know the drill thumb on scope tube, index finger wrapped around the bolt knob and grit your teeth…  I only recorded one round of 55.5grains @ 3634fps and proceeded to tear down the other two rounds and then measure the overpressure spent case.  With the shoulder push forward 0.100” I could not get the case to resize down with a F.L. die, that load will go in the load book as MAX pressure!  I plan to keep shooting the 75grain A-max loads until groups open to .75” consistently, a quick look at ballistic charts shows just less than 1000Lbs of retained energy can be expected with the H1000 load out to 400yards! That should hit like the hammer of Thor on varmints. Then I will start running lighter 50grain and 45grain pills down the bore to have fun with pushing high 4100+ fps velocities after all isn’t that the fun of experimenting with an overbore.


I was satisfied with the 100yard testing and started to set up at 200yards.  Even with the cartridges’ 35 degree shoulder tapper I needed to trim the case length and anneal the neck/shoulder area after 3 firings of a case.  Switching to the Barska Benchmark 40X scope allowed me to really see those tiny pin holes at 200yards, vertical stringing of shots seemed hard to avoid and my best 200yard group was a disappointing ½ m.o.a.   The temperature was mid to high 30 degrees, I was getting tired of a knee deep walk in the snow to retrieve my targets so I packed up the Dodge 4×4 and let the 5.7 Hemi do the work.

Later that evening while reading thru publications, keeping good records of interesting topics really helps out when working thru accuracy issues.  An article in the December 2012 American Gunsmith written by Norman E. Johnson titled “counterbalancing the stock” was just the cure!  All that was needed to eliminate vertical shot displacement was to add butt stock weight to help offset the 27” barrel and make the rifle track better in the bags, ½ pound of steel shot was poured into two 9/16” holes drilled into the upper section of the stock nicely hidden under the morgan adjustable butt pad.  The next trip out to the range was sunny and a balmy 45 degrees, pet load of H1000 @ 53grains and this time 230yard groups printed ½” for 3 shots! Yes I was really happy!

There are particular accuracy issues that plague an overbore .224 barrel,  the one I experienced was a need to clean out the copper fouling after only 9 rounds fired and are those patches BLUE!  I found the cleaning to go fairly quick thinking it might be a combination of barrel quality, cryo freezing process and the use of liquid graphite to coat the bore. The 22-284 proved to be an accurate cartridge right from the start with little fuss in finding a good load. Low recoil however with a very loud report upon firing, I will need to see how long cases last for reloading and I hope to get 1000 rounds down the bore before noticeable accuracy is lost with erosion.  Running a Quick Load program on the 22-284 for ballistic drop estimates have shown a 12” drop out to 400 yards (with a 230yard zero). I have included the actual drop elevations I recorded during range time with this barrel; your individual results may vary however this will be quite handy in getting you close to hits at different ranges.  With any custom cartridge the work and time spent is well worth the effort if desired results are achieved, I plan to be shooting plenty of pesky varmints with this Big .22 for some time now.


Thoughts on the Barska Benchmark 40X;

Initial load development with a 36X scope modified with a tucker style reticule lock proved the pet load to be accurate. Switching to the big 40X Barska at longer ranges will be a good test on the quality of their fixed power Benchmark line.  Built with a 30mm main tube, 50mm objective, click adjustable target turrents and side parallax adjustment this is one big scope.  I found the sight picture to be crisp and clear with bright edge to edge image. The mil-dot cross hair are a bit heavy for me but they do show up good and don’t wash out when scanning the woods for vermin, click adjustments tracked very good and the parallax adjustment worked very good althou you need to turn the dial very slowly to fine tune the sight picture.  The biggest gripe I have is the lack of horizontal hash marks on the turrent post, once zeroed and knobs reset you better keep track if you turn a complete revolution. Out to 300yards I could easily see the one inch grid marks on the target with a clear picture in 14 degree F conditions.



            22-284 Winchester
75grain A-max / 53grains H1000
B.C. .435 / velocity 3488 / Altitude 662′
Range Energy path
100yrd 1751 lbs 1.34″
200yrd 1504 lbs .87″
230yrds 1460 lbs zero
250yrds 1391 lbs (-).78″
300yrds 1285 lbs (-)3.46″
400yrds 1091 lbs (-)12.3″
42 F /  pressure 29.44 in. of mercury




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4 responses to “22-284 Winchester cartridge development

  1. John Greg

    Somewhere in my reloading room is a batch of .22 x 284 brass I picked up 20 years ago. I wanted to reform into 7.5 Swiss at the time but the necks split so gave up on that projrct if you are interested.

  2. Brad

    Wonder what the 22/284 would do in a 1-12 twist barrel with lighter bullets. I have reamer and take off 700 barrel in 223. Might have to give this a try.

    • The 22-284 is a fun cartridge to load for, I also have a new 22-250 barrel in 1-12 twist that I often consider rechambering to the big overbore 22-284. Don’t think it would shoot the heavy 75+ grain bullets well.


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