Wildcatting: A British Favourite

The .243 Winchester is universally used in Britain as the “default” deer calibre primarily due to the legal .240 minimum statuary requirements. Usually Roe are its main use but many a highland stalker uses it with 100-grain bullets for Red. Personally I have always seen it as more of a varmint round as it was intended and it is one of those cartridges that crosses the boundaries neatly from vermin to deer dependent on bullet choice.

If you think the .243 Win is lacking in oomph then why not try the Ackley Improved (AK) version which like all Ackley designs increases the powder capacity of the original case and puts more horsepower at your trigger finger for little extra input. It gives a better overall case design for minimum case stretch and of course that lovely 40° shoulder angle too.

CASE SPEC

The .243 AK or 243 AI either term is fine, usually dependent on brass used will hold 58-grains of H2O whereas the standard case holds 53-grains. Thus the AI version has a 5-grain advantage in useable powder capacity. That’s worth having.

Case length is 52mm whilst the shoulder is at 44.25mm (normal 243 40mm) and the neck is 45.75 to 52 mm. The squat boxy and sharp angled case walls and shoulder neck union stop the case slipping forward under firing as with the standard design and thus case life is improved and to some degree trimming reduced.

Fire forming is easy and can be done in two ways, using commercial ammo i.e. RWS loaded ammo for quality brass. When you load this into your AI chamber there should be a slight resistance as you close the bolt. If not I put each bullet into a kinetic bullet puller to ease the bullet on the factory load out slightly. I then use your seater die to seat the bullet so it is into the lands i.e. a good 10-20 thou longer. This will ensure when you shoot the case is square against the bolt face and the AI profile is formed perfectly.

REAMER CHOICE

Reamers are more problematic than some other AK conversions as the 243 can be had in varying forms and it is wise to check with the reamer maker or custom rifle builder what variant of the design is being used. It’s important as you can run an AI two ways, slow twist for fast light bullets or fast twist for heavier long range performance. The latter is usually the most common but I have known chaps to shoot 55-grain ballistic tips screaming out of their barrels, but not for long as the rifling will soon follow it!

I see the 243 AK as a fast twist option, throated long to gain maximum powder capacity and using streamline heavy 6mm bullets in the 105-115 grain range i.e. Hornady A-Maxes and Berger VLD’s. This way you have yourself a superb long range, light recoiling, wind bucking varminting tool that with the correct deer legal bullets also becomes a creditable deer rifle.

LOAD UP

As with the .243 Win the AK version likes medium to slow burn rated powder and it helps to have a long barrel to burn these efficiently. This also helps reduce the fact that you are stuffing a lot of powder down a small hole/bore and thus rifling and throat erosion is in some way reduced.

Powders such as H4350, RL19, Vit N150, H4831SC or even H414 are all worth trying but as we know the rifle chooses the powder not the other way round, Mr Potter. Reload kit is also common as the 243 AK is a popular number. Nearly all the major manufactures offer dies but make sure its 243 AK or 243 AI and not 243 Improved as there is a difference!

I used Redding Type S dies, in full length bushing configuration as this allows you to bump the shoulder if necessary and alternate the bushing sizes inside to vary neck tension and match your custom 0.270 thou chamber perfectly. I used a 0.266” bush which gave a 2 thou neck tension on 12 thou neck turned necks for one thou a side clearance either side of the case in the chamber on a 0.268” thou loaded 105 grain A-Max bullet.

Bullets are seated with either a Redding Comp seater die or I also have a set of Wilson 243 AK dies and the arbour and seater die gives a better control on seating in my view, especially with a thinner neck and tighter chambering. Having said that I have also used the RCBS FL die set group G and they work really well as is!

 

RIFLE DESIGN

I have shot a few AK 243’s that have been blue printed but the most accurate was the RPA re-barrelled version in these tests. It has a standard RPA Interceptor designed stock and uses a Quadlite action with .308 bolt face. To this a Pa-Nor 3 groove stainless steel super match grade barrel is fitted with a 1 in 8 twist rate to stabilise 100-grain bullets. The 115- grain bullets actually need 1 in 7 twist but I thought I would try them anyway. The chambering has a tight neck at 0.270” so necessitates neck turning for a precision yet correct fit. The barrel length is 26” inches and wears a custom fit, over the barrel MAE 38mm sound moderator.

 

FIELD TEST

The RPA was a winner from the get go. The Quadlite is a strong action and gives a stiff solid lock up and matched to the Pac-Nor barrel it shot very well indeed. Quickload came up trumps again with the .243 AK Improved in its data base and providing a very good guide to matching powders to bullet weights. Best light bullets were the Hornady 65-grain V-MAX and yes they held together in the 1 in 8 twist barrel although I suspect that a 1 in 12 or even 14 would have less pressure and higher velocities.

Most accurate load and designed really for longer range Varminting were the 105-grain A-MAX, the 115-grain Berger’s had better BC ‘s but the A-MAX just shot well! Loaded with 44.5-grains of RL19 for 3003 fps they were phenomenally accurate down range (bit hot so work up slowly). Check that 300 yards group! Less than an inch for 3-shots, that’s a rattled crow in anyone’s book!

They also buck the wind well down range with their high 0.500 BC value. At 300 yards you have 4” inch wind drift compared to a standard .243 100-grain bullet of 6” and at 500 yards the drift is 14.5 inches. So very competent on crows or bunnies.

 

CONCLUSIONS

Let’s be honest, most people will be happy with the standard 243 Winchester but savvy shooters who like their ballistics will notice a difference with the AK configuration. Improved case life, great looking and at least 200 fps advantage with the right powder and barrel lengths make the 243 Ackley a very good medium case length cartridge. Loaded with expanding bullets it’s great for deer, ballistic tips scream down range at crows and buck the wind well, whilst long range nerds and even 1000 yard shooters can eke out the benefit from these easily improved cartridge design.

CONTACTS:
PAC-NOR www.pac-nor.com Barrels

RPA www.rangemasterprecisionarms.com Quadlite actions, rifles

JMS ARMS 07771 962121 MAE sound moderators and Quickload/ Quicktarget ballistics program

NORMAN CLARK, 01788 579651 Berger bullets, reload supplies precision dies and cases

PTG www.pacifictoolandgauge.com Reamers

EDGARS 01625 613177 Hornady bullets Hodgdon powder