280 JDJ and 375-284
My brother likes to play with off the wall stuff, and he's a big Encore fan. Two of his barrels are in difficult to find wildcat cartridges, and I'm trying to find load data without much luck.
The 280 JDJ is a 15.5" Encore bbl from SSK Industries and the load data they provided is minimal at best. We'd like to shoot 140gr X-bullets through it, but the closest load data is with 145gr Speer Grand Slam. I know the X-bullet is a lot different to load for than a traditional bullet, and I don't want to overload. There has also been a bunch of new powders since he bought the barrel 10 years ago...
The 375-284 is a 15" Encore bbl from Bullberry, and they didn't give any load data. As the 284 case is essentially a 30-06 capacity, I tried to find data for the 375 Whelen but nobody lists anything except the Ackley Improved version, and the 375 Schofield isn't even close. As we've got 4 boxes of 250gr Barnes X-bullets, that's what we'd like to load.
None of the powder manufacturer's books list either cartridge, Cartridges of the World only lists the 280 JDJ and the load data is what we already have from SSK, and Barnes doesn't list either cartridge in their manual.
I'm sure it's too much to hope someone here has been successfully loading either of these two cartridges and has a proven recipe so...any suggestions? Places to look? Manuals to buy?
Murphy is the wildcat guy but I think he's out of town now. I bet he has data when he gets back.
Would the case capacity of the 375x284 be similar to the 35 whelen? There are 250 gr 35whelen loads published, Could be a good place to start. Begin low and work up gradually.
Case capacity is virtually identical but the bore is significantly larger, creating a much greater expansion ratio. Powders good for the 35 Whelen are marginal for the 375.
Originally Posted by EricG
Some links that may help, with the 375-284.
Also here is a picture of the page from Handbook for shooters and reloaders Vol 1, by PO Ackley for the 375 whelen. Note this data is rather old and much of the loads in Ackley's books are rather hot, also these books are full of misprints, a think the 350 bullet weight should really be 250.
From Cartridges Of The World 11th edition:
280-JDJ all max loadings!!
120 Nosler BT ~ 70 graines IMR4831 ~ 3119fps ~ 2590lbs
140 Nosler BT ~ 67.5 graines IMR4831 ~ 2975fps ~ 2750lbs
140 Nosler Partition ~ 68.4g RL22 ~ 2775fps ~ 2565lbs
175 Remington ~ 64.3 g IMR4831 ~ 2670fps ~ 2770lbs
375-284 is AKA 375-06-JDJ in my books all max loadings!!
220 bullets ~ 55.6g AA4350 ~ 1825fps ~ 1625lbs
220 bullets ~ 67.3g Varget ~ 2601fps ~ 3305lbs
270 bullets ~ 65.2g N140 ~ 2421fps ~ 3515lbs
300 bullets ~ 63.4g IMR4320 ~ 2330fps ~ 3615lbs
Donít know if thatís any help but there it is. I would drop about 5% off the powder charges and work up with them.