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The 22-250 Ackley Improved Project

By: Mike Barton

This is a project I began thinking about sometime ago. In Jan.05 I decided to do it and build a wildcat capable of consistent 700-yard shots on prairie dogs. This article is being written as the project comes together. After doing some ballistic comparisons, I narrowed the field to three potential cartridges suitable for the task. 1) 243A.I., 2) 6mm A.I., 3) 22-250A.I. with a fast twist for stabilizing "heavy for caliber" bullets. Surprisingly to me the 22-250AI was right in the hunt with wind drift, and bullet drop at 500 yards and beyond when comparing 75 grain .22's to 87 grain 6mm's, even slightly better than the 243AI ballistics at longer ranges. The down side of the 22's is no dedicated varmint bullets are readily available weighing over 60 grains. However I'm told Sierra is coming out with a 69 grain Blitz King this summer. That being the case and since I have about 800 pieces of 22-250 brass collecting dust, 22-250A.I. is the caliber of choice.

I called Sharp Shooter Supply and ordered a trued, bead blasted, Savage stainless single shot barreled action with a 26” 1-8 twist Douglas barrel. The action has the accu-trigger, which I find adequate. Approximate 6-week wait until completion. Upon arrival of the barreled action the receiver had not been bead blasted as ordered although the barrel had been. Not really what I wanted but I suppose it’ll grow on me. The scope is a Burris 8-32 Signature. I like these scopes and now have three although they do not have an abundance of adjustment. I just happened to have a set of Burris Signature rings with inserts for additional adj. So those were used with 15 minutes of angle built in. A Boyd’s stock was special ordered but the order was lost and the stock did not get made, so a Richards Micro Fit was then ordered, another 8-week wait. In the mean time a BVSS stock borrowed from friend and fellow prairie dogger Jim Patterson will do for load development.

A propane torch with an annealing tip is used to soften old 22-250 brass with multiple firings on them that surely have become brittle. 15-20 seconds at the shoulder, work up through the neck, tip into water for cooling, and go to the next case.

Initial fireforming produced great results. Some previously loaded ammo for another rifle chambered well and brass comes out perfect using 50 grain Blitz Kings. Also some 60-grain V-Max’s charged with 32.0 grains of H-4895 and WLR primer are remarkably accurate and produced 3400 fps. This is the load I intend to use while fireforming brass on prairie dogs.

RANGE DAY 5 - After a few range trips and after gaining some fireformed brass, Load development began with 75gr A-Max’s in the improved case. 6 loads of 4 shots each are assembled with variances in powder charge and primer type. All do well with the bullets seated .003” into the lands. 38gr 4831sc / Rem 9 1/2 primer / 75 A-Max produces a .445” group but the velocity is not acceptable at 3050fps. 40 grains of H-4831sc, and WLR primers at 3150 fps has my attention simply because it is the fastest so far with a group measuring .530” and testing continues….

RANGE DAY 6 –
Two loads were fired using 40.4g and 41.0g H-4831sc and the 75 A-Max group in the .8’s @ 200 yards with velocities from 3150 to 3200 fps respectively. 41grains of H-4831sc seems to be the absolute maximum limit as it exhibits cratered primers.

RANGE DAY 7 –
38.3 grains of H-4350 and CCI BR2 primers with the 75’s seated just .003” into the lands produces a .582” and .800” group at 200 yards with muzzle velocity above 3400 fps. This will be the load of choice for July PD’s. POI is about 1” lower with this load @200 than the 60 grain fire form load so that works too.

June - 2005:

The Richard’s stock shows up, 16 days before I’m scheduled to leave for the prairie dog towns. The best I can figure from talking with others, the Savage inlets must simply not be as good as the Remington or the 10/22 inlets from Richard’s.

I’ve read several reports of extremely rough stocks from other Savage owners but other reports of very little if any inlet work and a finish sanding was all that was needed for other inlets. Anyway this one came pretty rough and took almost 3 hours to get it fitting in the stock well enough that I could start beginning to think about bedding. I started sanding the exterior with 80 grit paper. It’s a hefty hunk of wood though and should work out well. This picture shows the stock just after getting the action to drop in while the exterior is still unfinished.

The high cheek piece needed to be cut way down to allow the bolt to be removed for cleaning. The grip was also much too fat for me, some wood needed to be removed there. A high gloss finish was desired on this one. I’d used Minwax satin polyurethane in a spray can with good results before. So the gloss type was purchased, 4 or 5 coats applied. Wet sanding with 500 grit paper before the final coat.

Day 1 in the dog towns and I’m anxious to try it out. Fireform loads are quite effective out to 600 yards. A 900-yard kill is made with the 75 grain A-max in the Ackley brass. I was hoping to get a calm day throughout the week to see if I could stretch it to 1000 yards but each day was very windy and with only 200 rounds of formed brass I kept waiting for the right opportunity but it never came. The one day when I had some 1000k yard shots available, cattle moved on to the next rise and the fear of ricochet kept me from trying that shot. The final day wind is blowing at 30 mph and the longest shots available in the field are 645 yards. I took several dogs at that range quartering into the wind without much trouble until the last of the rounds was gone. The 75’s seem to cut the wind even better than expected and only needed to lead the wind by “½ a dog” at that range. Another concern had been the bullets performance on live targets. The A-max does not have the explosive results of the V-max but killed very effectively. PD’s were thrown off the mounds like rag dolls on impact.

Bullet impact was easily visible with the heavy gun at 20-24 power from 400 yards on out. The weak link in this set up may be the Burris Signature scope’s lack of adequate adjustment range. A good deal of hold over was needed for the 900 yard shot as I’d run out of clicks on the scope. It will be shimmed a bit more.

In short, the quest for a consistent 700-yard gun has been realized. The rifle hits with extreme precision once the range is figured. I’m more than happy with the result; the “22Howitzer” is here to stay.

Thanks again to Fred and Lisa Moreo of Sharp Shooter Supply, Jim Baker of Savage Shooters for his guidance on powder and bullet selection, and to Jim Patterson for the loan of the stock during load development and making me laugh for a whole week of dog shooting.

 

Editor's Note: Mike Barton has been a hunter for 37 years. He started varmint hunting at age 14; aquiring his first high-powered varmint rifle at 15 years of age. He is an accomplished hunter & shooter. Besides being a writer, he is also a moderator on the Varminter.com Online Magazine Forums - EM

 

 

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