6mmAR.com    
Call Us: (215) 348-8789
Home Page Products Custom Uppers Dies Parts Specials 6mm AR Loads
Turbo 40 Imp. 6mmAR Turbo 224 AR 22 Beast 20 Practical 20 Tactical 6mm HAGAR
Info Page Varminting Benchrest AR Left Hand AR-15 Set Up Vendors 6mm Super LR
6mm Dasher 6.5 Super LR 6mmBRX 260 Imp 30˚ 243 Imp 30˚ Pictures New Products
30 ARX 6XC II Barrels
The 243 Imp 30˚ Cartridge

A 243 Imp 30˚ case (right) next to a factory 243 Winchester case (left).  The 243 Imp 30˚ has a case capacity larger than a 243 Win. but  it incorporates a slightly longer neck and the renowned and accuracy proven 30 degree shoulder angle.  The net result is that the 243 Imp 30˚ is a very efficient, consistent and accurate performer, with the capacity to easily push the 105-115 gr. bullets in the 3000+ fps range.


An Easy and Accurate Ackley Type 6 mm Cartridge but with the Proven 30˚ Accuracy Shoulder


The 243 Imp 30˚ is a 6 mm wildcat cartridge with a powder capacity larger than the 243 Winchester but with a slightly longer neck and the proven 30 degree shoulder angle that is seen so often in the top performing accuracy cartridges.  It was designed for rifles (bolt guns and semi-automatic rifles) that have a .308 bolt face and can handle a cartridge of that size.  It is not suitable for use with an AR-15, but will work out of rifles like a short action Remington 700 and semi-auto rifles like an Armalite AR-10, a DPMS LR-308, etc.


The 243 Imp 30˚, in addition to being a great long range 6 mm cartridge, is also a viable cartridge for magazine feed applications from a short action magazine (high power competition, tactical matches, etc.) especially where the use of the 105-115 gr. can provide superior long range performance, all with minimal wind drift on windy days.

Note:  If you are looking for someone to chamber your rifle or re-barrel an existing rifle in the 243 Imp 30˚ cartridge, Fred at Sabreco, Inc. in Skippack, PA (610) 584-8228 can help you with this.  He has the reamers for the cartridge as well as the head space gages for the cartridge, and has had extensive experience setting up and chambering many barrels and rifles in the cartridge.


The 243 Imp 30˚ Cartridge


The 243 Imp 30˚ has some excellent attributes:

- Very easy to make!  Chamber uses common and readily available 308 Win. head space gages (i.e. no special head space gages required).

- Chamber accepts factory 243 Win. brass or ammo for fire forming with no modification.  Load up 243 Winchester brass or take 243 Winchester factory ammo, stick it in your gun and shoot it - - - DONE!

- No initial neck turning or trimming required. 

- Works well with existing Lapua, Winchester and Remington 243 brass.

- Sizing dies and die sets are available and in stock.

- Adequate case capacity for top velocities.

- Chamber Reamer drawings are available for you to use (see below) to have your favorite reamer maker or gunsmith obtain a reamer.


Die Sets Readily Available - Call (215) 348-8789 To Order


Loading die prices:


Die Set - Redding Type S FL Bushing Die with Redding Competition Seater - $224.95

Sizing Die Only - Redding Type S FL Bushing Sizing Die - $114.95

243 Imp 30˚ Modified Case - $15.00


Reloading dies are readily available for the 243 Imp 30˚.  At the time of the writing of this, factory 243 Imp 30˚ dies have been made by Redding (i.e. Type S. FL Bushing die and Competition Seater) and are in stock.

           

Working With The 243 Imp 30˚

 At this point, I have two barrels chambered up in the 243 Imp 30˚, and both of them shoot very well.  The cartridge does not seem to be finicky and it seems easy to load for.  In addition, there are a lot of popular powders that work very well with the cartridge, including H1000, H4831SC, H4350, Reloader 17, Reloader 19, Reloader 22,  VihtaVuori N160, N560, and N165.



Some Initial Chrono Results - 30" Krieger 6mm 1:7.5" twist barrel:

Fire forming loading (very accurate in author's rifle) to fire form Winchester
brand 243 Win brass:

47.5 gr. H1000, Berger 108 gr. BT bullet .015" in the lands = 2990 fps

43.5 gr. H4831SC, Sierra 107 gr. bullet, .020" jump to the lands = 2967 fps

Loads with fire formed brass using Winchester brands brass:


47.5 gr. H1000, Berger 108 gr. BT bullet, .015" in the lands = 3017 fps

47.5 gr. H1000, DTAC 115 gr. bullet, .015" in the lands = 2974 fps
47.5 gr. H1000, DTAC 115 gr. bullet, .040" jump to the lands = 2929 fps
48.0 gr. H1000, DTAC 115 gr. bullet, .015" in the lands = 2994 fps
48.5 gr. H1000, DTAC 115 gr. bullet, .015" in the lands = 3029 fps

47.0 gr. H1000, Berger 105 gr. Hybrid Target bullet, .015" in the lands = 3018 fps
48.0 gr. H1000, Berger 105 gr. Hybrid Target bullet, .015" in the lands = 3087 fps
49.0 gr. H1000, Berger 105 gr. Hybrid Target bullet, .015" in the lands = 3149 fps
50.0 gr. H1000, Berger 105 gr. Hybrid Target bullet, .015" in the lands = 3204 fps

42.0 gr. H4831SC, Berger 105 gr. Hybrid Target bullet, .015" in the lands = 2893 fps
43.0 gr. H4831SC, Berger 105 gr. Hybrid Target bullet, .015" in the lands = 2973 fps

43.5 gr. H4831SC, Sierra 107 gr. bullet, .015" jump to the lands = 2986 fps

43.5 gr. H4831SC, DTAC 115 gr. bullet, .015" jump to the lands = 2999 fps
43.5 gr. H4831SC, DTAC 115 gr. bullet, .015" in the lands = 2993 fps
44.0 gr. H4831SC, DTAC 115 gr. bullet, .015" in the lands = 3013 fps
44.5 gr. H4831SC, DTAC 115 gr. bullet, .015" in the lands = 3044 fps



Reamer Prints Below (three different prints)

The 243 Imp 30˚ reamer just below is shorter throated and was set up for smaller varmint bullets and/or also magazine fed rounds out of a short action while keeping bullets close to the rifling at a magazine length OAL



Shorter Throated Reamer Above
________________________

Mid Length Throat Reamer Below (Throated predominantly for 105-108 gr bullets)



Mid Length Throat Reamer Above (Throated predominantly for 105-108 gr bullets)
________________________


Long Range Reamer Below (Throated long for 115 gr. bullets)

The 243 Imp 30˚LR reamer below is throated long and is ideal for loads keeping the full bearing surface of 115 gr. bullets  forward of the neck/shoulder junction of the case.



_________________________

Max Case and Trim Length for 243 Imp 30˚ Brass Cases

There is no formal established max case or trim lengths for the 243 Imp 30˚ brass.   The author suggests the following for guidelines:

Max Case Length:  2.045"

Trim Length:  2.035"























Website Builder