Reduced loads with SR4759

[okiecat]

[BD264]

Good question.

Maybe another idea is using 4895, reduce per Hodgdon's 60% rule?

[kmon]

You can get there with H4895 and their rule for reduced loads like said above. I don't remember the last time I saw any SR4759.

[BD264]

I've got a couple pounds of it, but have never really thought about using it in my Grendel rifles.

[okiecat]

[tdbru]

okiecat,
i'm sure you can find a load for SR4759, a very good reduced load powder, with some trials. of course it was discontinued about a decade ago so you're not likely to find any load data for the 6.5 Grendel. However if you look through older reloading manuals for cartridges that have about the same case volume to bore area ratio as the 6.5 Grendel, and then start with those listed starting loads on a percent basis of a full case, you'll likely be ok. for example, and i'm just guessing here so DO NOT assume i'm correct, but say the 300 WM has about the same capacity of water to the 30 caliber bore area as the 6.5 Grendel capacity to 26 caliber bore area. if they are similar, then look at the SR4759 starting load for, one of the heavier 300 WM listed bullets. say for example it's 20 gr. and say the 300 WM has a capcity of 80gr. then the SR4759 starting load for the 6.5 Grendel with a 123 gr. bullet, for example, might be 1/4 of the case capacity. or 30/4 ~ 7.5gr. this is not a recommendation for a starting load however. it's just a suggestion on how to proceed, other than by guess and by golly, to trying to figure out where to start with the Grendel with SR4759.

i still have some too, and use it mainly for CBs as most did.
good luck,
tdbru

[Dinny]

I have 2-3lbs of it too. Tagged for future reading.

Thanks, Dinny

[okiecat]

[tdbru]

okiecat,
i did a web search and came up with 35gr. of water for the 6.5 Gr. case. on a water gr./bore area that comes out to ~639. in 30 caliber you'd need a case that only held 48gr. of H20 for the same ratio. that's slightly less water than a 300 Savage case will hold(~52gr. of H20). i have a RCBS cast bullet manual #1 that lists a 20gr. starting load of SR4759 for the 180gr. CB. 20/52*35 ~13gr. Because the CUP max for the 300 Savage is higher than the 6.5 Gr. i'd probably start around 10gr. of SR4759. I will say, here, that you're on your own and my method of estimation may be way wrong. you are warned. use your own judgment. but that's how i'd go about trying to find a starting load. I don't think at 10gr. you'd stick a bullet in the bore, unless you have an unusually long barrel. i highly doubt that 10gr. would cycle an AR. in a bolt gun of course that doesn't matter. just trying to help. let us know how it goes.
-tdbru

[A5BLASTER]

You can do it with any powder.

Just use a min charge and place the gel block at the range the ballistic calculator tells you it hits those speeds.

[LR1955]

OC:

I used to use it for black powder cartridge rifles. We used about 1/2 the black powder charge of 4759. We liked it because it filled the case more so we didn't have to use a filler.

Best I can find on 4759 is that It compares with 4198 and Reloader 7 which means it is way too fast for the Grendel.

LR55

[okiecat]

[LR1955]

We went 40% of a full bore load of black powder, not smokeless. Also, we were shooting primarily straight walled cases, not bottlenecks. And we were shooting relatively soft lead cast bullets, not modern jacketed bullets.

You are talking about ten or fifteen grains of 4759 and a jacketed bullet in a Grendel case?

I wouldn't go there.

LR55

[BD264]

I thought I would test out 4759 with a Lyman 266469 (143g) sized .265 with a g/c. I started at with 4 previously fireformed 7.62x39 cases that I have just lieing around. Typically for fouling purposes. Cases are Starline 7.62, cci 200 primers.

6.5g sr4759 = 863fps
7.0g sr4759 = 910fps
7.5g sr4749 = 969fps
8.0g sr4759 = 1078fps

Gun used was my Howa Mini 1500 20" hb.

[Dinny]

BD,
Thanks for the info. I have a couple questions. Do you powdercoat your bullets? Do you feel there's room to load more powder? How was accuracy?

Thanks, Dinny