.303 British New Powders New Loads

[Rebel Rouser]

http://www.shootersreport.com/reloading/new303britishloads.htm?fbclid=IwAR31LanhcX_cLVp2CkmryhWDpmf4AH1108vRC9aW6jmfJchi5KFCiI8zEtM

Reloading Caliber .303 British
with IMR 4166 and 4451 Enduron Powders

Featuring Small Kernels for Easy Metering and a Built-in Copper Fouling Eliminator

In 2015 IMR introduced three new Enduron powders, more particularly, IMR 4166, IMR 4451, and IMR 7977. All three of these new propellants feature small kernels for easy metering and a built-in copper fouling eliminator. Morever, Enduron powders are not sensitive to temperature changes. But here lies the real eyebrow raiser: according to Hodgdon, its IMR 4166 is nothing less than a "versatile, match grade propellant".

With that preface in mind we present load data for two of the three powders in a variety of bullet weights and loads. And we've fused into that load table some information on the ubiquitous .303 Mark 7 military load as well as factory Remington 174 and 180 grain weights, which lends perspective on relative velocity. Also for perspective's sake, we've included load data for IMR 3031. That's for the simple reason that venerable Improved Military Rifle 3031 was the first propellant after Cordite to be loaded in the .303 British.

Powder Bullet Weight Bullet Diameter COL Primer Charge (grains) Velocity (fps) Pressure Charge (grains) Velocity
(fps) Pressure CUP
IMR 4166 125 .311 2.915 Remington Large Rifle 44.2 2,739 37,500 47.2 2,907 43,000
IMR 4166 150 .312 2.995 Remington Large Rifle 39.9 2,477 36,400 43.9 2,693 43,600
IMR 3031 150 .312 2.995 41 2,632 46,100 PSI
Remington Factory FMJ 174 .311 3.075 2,475
IMR 4166 174 .311 3.075 Remington Large Rifle 2,475
IMR 4451 174 .311 3.075 Remington Large Rifle 45.6 2,397 36,800 49.6C 2,590 43,300
Military Mark VII load 174 FMJ .311 3.075 2,440 45,000 CUP
(SAAMI Max)
Remington Factory Core Lokt 180 .311 3.075 2,460
IMR 3031 180 .311 3.075 38.3 2,341 46,500 PSI
IMR 4166 Speer 180 Hot-Core .311 3.075 Remington Large Rifle 37.5 2,265 34,900 40.8 2,453 42,300
IMR 4451 Speer 180 Hot-Core .311 3.075 Remington Large Rifle 45.2 2,361 37,300

Tried to reproduce the chart, just klick on the link.

 

[9.3 Hunter]

Thx much for posting....theres some more good info regarding the newer powders and data. Helps me out!

 

[RonR]

x2 thanks for posting.

I tried 4166 in my son's 303br with 180gr Campro. I wouldn't hesitate to complete the load development. Availability and price in Saskatoon is of concern for myself but when I come across some more at a reasonable dollar I'll purchase with confidence that it will produce satisfactory results. I'd give 4451 a try as well to satisfy my need to work with something a little non traditional.

It's promising in a ladder and clean, as good or better than Varget in that regard. Better results in his rifle than W760 and Varget using 180 gr bullets which may have been predictable. N540 and 4166 are producing the best results so far but going to try BL-C(2). Literature pointing to some good velocities. We'll see.

Regards
Ronr

 

[fishinmusician]

Some great info here!! Thanks

 

[Why not?]

Another great powder in the 303 Br is Ball C2. I have used it in several rifles to get 180 bullets well past 2400 fps with good case life in Lee Enfield rifles.

Ted

 

[Eagleye]

Reloder 15 and Vihtavuori N540 are great performers in the 303 as well. I load for a 1910 Ross,
so can stoke them up a bit. Have one 180 grain load at 2610 fps, another at 2635 fps avg. D.

 

[buckbrush]

Eagle eye, you can really hot rod loads in a ross. I have settled on H4350 for all 10 of my .303's with both cast and jacketed loads. I use the same sizing die and setting for all 10 chambers and have not had a case separation with it. Olin 760 works almost as well but velocity really drops in the cold. I do not neck size, this is partial sizing with a RCBS f. l. die.