Winchester 760 powder Data for Cast 30-30 Bullets

[tcomer]

How low can I go using Winchester 760 powder? I decided to get into low power loads using Laser Cast 170gr bullets and 10grs of Unique in my 30-30 Win 94. Really a fun plinking load. I have several pounds of 760 laying around and wondered how much lower I could go in Win 760, but my Lyman cast book doesn't list it. My Lyman cast book lists a few powders that the Sierra book lists, and the Lyman book's starting loads are a lot lower. Here's an example. Sierra lists a minimum of 27grs of Win 748 for a speed of 1800fps for the 170grn bullet. Lyman lists a minimum of 24.8grs of Win 748 for a speed of 1613fps. So, does someone know of a lower starting load for the Win 760 powder for cast bullets?

[Terry Murbach]

RIGHT OFF HAND, NO. THERE IS A GOOD REASON FOR IT TOO AS BALL/SPERICAL PROPELLENTS DO NOT DO WELL AT ALL IN SUBLOADS. THERE ARE PLENTY OF APPROPRIATE PROPELLENTS FROM WHICH TO CHOOSE; JUST 'CAUSE YOU GOT IT AIN'T A GOOD REASON TO CHOOSE IT.

[tcomer]

The starting loads for all the powders in the Sierra book are at 1800fps. I had hoped that since the Lyman book had a smaller starting load for the other powders there might be one for the Win 760. 10grs of Unique is around 1500fps and is a pleasant load to shoot. I'm worried that 1800fps might be pushing it for these .310 unchecked cast bullets.

[junkbug]

Terry is right.

Ball powders will not butn properly if a certain loading density is not achieved. Go just a little below the starting load, and pressure becomes erratic. Not necessarily dangerous, but accuracy goes to pot. Go too low, and the powder will not really ignite at all, just burn a little, creating a carbon blob in the chamber, plenty of un-burnt and underburnt powder, and leaving you with a stuck bullet.

I did this with an old military rifle (one of the big rimmed 8mm rounds) and factory reloading data that was too conservative, and using a slightly undersized bullet that simply did not allow pressure to build up fast enough for the powder to burn as designed. As I said, several stuck bullets. Fortunately I checked the bore after evey shot, and had a dowel handy.

I believe Win 760 is not typically listed as a powder for the 30-30. Even at full loading density, it produces lack-luster velocity. One again, you can use it if it is all you have, as it is slower than Win 748, but even with a full case, velocity will be low, and you will probably get a lot of un-necessary muzzle flash. However, if it makes for a very accurate load, then it may be woth it.

Sean

P.S.
You can probably go as low as 7.0 gr of Unique and still be OK. Unlike Win 760, it is a fine low loading density powder. Unique, Red Dot, 2400, and SR4759 have worked well for me with cast bullets in several high power rifle cartidges.

[1886]

Great advice. The bullet you are using my not behave well with reduced pressure loads. It may be too hard. 760 is not a good candidate. You may need a softer projectile and a powder designed for your goals. Bear Creek Supply offers great soft cast bullets and Trail Boss is a good low velocity powder. 1886.

[tcomer]

I'll still use Unique for the low velocity loads. Didn't have much luck at 8grs so I bumped it up to 10grs and got a little better accuracy. I'll know to get a softer bullet next time. Just wanted to know it I can reduce the 760 to an acceptable level for the cast bullets. The Sierra second edition book that I have lists loads with the 760 for every bullet but the 125gr one. Or do you think the Laser Cast bullets can handle 1800fps? I bought 1000 of them when they were on sale.

[junkbug]

As long as the load is safe, all you risk is leading up your barrel, and the hassle of cleaning it out.

If you have any sizing dies as all, you might try wrapping standard plumbers teflon tape around your bullets, and sizing slightly over slug diameter. Even with no sizing die, it is possible to just wrap teflon tape around your bullet, and load them. Without sizing, loading becomes more tedious, and neck belling more critical.

Teflon tape and cast bullets is mentioned in the out of print "NRA Cast Bullet Handbook". I have done it both ways, and it does reduce leading, all else being equal.

Sean

[Modoc ED]

Did you think of going to the Hodgdon site for Winchester 760 info?

Hodgdon list 33.6gr of 760 for a 170gr SP at 1975 fps @ 30,000CUP. It's not a low velocity load but then again -- why mess with Mother Nature so-to-speak.

[Sixgun]

Way too slow, especially with cast bullets. Cast bullets need a fast to at most medium powders to work efficiently. Why waste the time and energy.-------Sixgun

[Marc]

760 is an excellent powder for heavy(200 grains and up) cast bullets in the 30-30 if you want maximum velocity at levergun pressures. It will give all that little case has in that application and with good accuracy in my 30-30. I have never tried reduced loads with it for all the reasons listed above.

[tcomer]

It's funny how the Lyman (Third Edition) book has no listing for 760 in the 170gr bullet, but lists it for the 173gr bullet. Even says the 28.4grs of powder at 1625fps is the potentially most accurate load of the powders listed. The book says "760- A rifle powder covering a broad range of applications where a higher loading density with cast bullets may be desirable." The book is kinda funny how some calibers and bullet weights have a wide rand of powders and some have hardly any. Some of the big thumpers only list Unique. I ordered this powder by accident. Checked the wrong box. I meant to get 748 so I'm just trying to figure out what I can use it in. I just saw 760 listed for the 173gr bullet but not the 170gr one. Figured I'd check in here and ask the experts.

[Marc]

I don't think you can get in trouble with the load you found for the 173 grain. If 1625fps is in the velocity range you want then I would not hesitate to try it for the 170 grain. Not enough difference there to matter. 28.4 grains fills the case enough to be in my comfort range. The Sierra 27 grain load is probably fine too. I would hesitate to reduce it much below that. The newer lots of the ball powders do seem to be better behaved than the earlier lots. 760 is one of my favorite powders!

[tcomer]

Leading is my main concern. These bullets seem to be hard. Even at 8grs of Unique, I got tiny flakes of lead. Same thing with the Laser Cast in my 357 and 44 levers. Flecks of lead. Not much. Not sure why as normally with other cast bullets I bought I'd get slivers if they leaded. I've always loaded for pistol calibers and this is my first attempt at a rifle.

[w30wcf]

tcomer,
W760 and H414 (same powder) are excellent in the .30-30 with heavy gas checked cast bullets and full power loads. Not so good for loads reduced by more than 10% below maximum.

If your 170 gr. cast bullet wore a gas check a capacity load would work very well, but for your plain based bullet, not the application for this powder.

The only exception would be to charge the case with 33 grs., fill the rest of the case to 1/2 way up the neck with polyethylene shot buffer, then seat the bullet. The buffer acts as a gas check and that combination will give good accuracy.......I know, I've tried it.

w30wcf

[tcomer]

Thanks for the replies. I've bought cast bullets for the pistol calibers for years and decided to try it in the 30-30. That's why I bought some Unique to start out with. Does anyone have an idea what the "speed" limit is on these bullets without gas checks? Ballpark figure? 10grs of Unique with magnum primers is about the max I want to try with that powder. I'd like to try to go a little faster as accuracy did improve from the 8gr initial load I first tested.

[Hobie]

Yep, like all PB bullets, about 1200 fps. BUT it sounds to me as though they don't fit your bore correctly. What is the diameter of your bullets and what does your bore slug out as (to be)? Your bullets should be .001-.002" over groove diameter. Frankly, as pointed out by others, you're trying to make something of this combination it is not. Get some good GC bullets for the fast loads or continue to load these bullets to to the 1200 fps level. I recommend 8-12 gr. (IIRC) IMR SR4759 in preference to using Unique.

[tcomer]

Bullets are sized at .310 according to the box and that's what the few that I measured came out as. My Lyman book shows SR-4759 but lists the minimum as 15.5grs of powder for 1613fps. Guess I'm barking up the wrong tree trying to push 'em a little faster. I don't cast and have no equipment to put gas checks on these bullets. They are a gas check design but I was told they would be fine at lower velocities. I just didn't know what velocity I could get by with without using the gas checks.

[w30wcf]

tcomer,
You just may find happiness with 12.0 grs. of 4759. I've used that charge with 170 gr. plain based bullets (mine) and they shot well with no leading. Velocity was around 1,300 f.p.s.

w30wcf

[tcomer]

Thanks. Next time I head to the big city, I'll look for some IMR-4759

[tcomer]

One more question then I'll quit on this subject. Where can I find load data for the IMR-4759 for the 30-30? 15.5grs is the lowest charge in my book. I'd like to see load data for lighter bullets also as I'm not sure if I'm going to stick to Laser Cast bullets. Jeeze, if I ever get the nerve up I'm going to slug this gun just to see exactly what I need. But I've gotta shoot these bullets up first.

[w30wcf]

tcomer,
4759 is a very flexible powder and I have found that 12 grs. works very well with 170 gr plain based bullets. A 1950's Lyman handbook shows a starting load of 10 grs. with a 154 gr. plain based bullet.

5744 is also a good powder for your application. Add 10% to the 4759 charge for equivalent velocity.

w30wcf