All,
Based upon some discussions here and the need for some inexpensive bullets I ordered Bear Tooth Bullets in .375, .416 and .423 (404 Jeffery). I am now looking for loading data for the 375 Ruger with 250 grain bullets, the 416 Rem Mag with 325 grain bullets and the 404 Jeffery in 380 grain bullets. I believe RIP had posted some 404 loads in the past, but I cannot locate them.

Also, how fast can you push these bullets without the bore leading up? I thank you all for your help.

After having a long conversation w/ Marshall Stanton at Beartooth, I ordered 335g cast for my 416 Taylor. He informed me that it is VERY important that cast bullets NOT be seated below the neck/shoulder junction due to the fact that cast bullet bases could obturate and increase pressures. He suggested filling the case w/ 4831 and seating the bullets no deeper than the length of the case neck. The slower powder decreases both the pressure and possible pressure spike. He said he would not be surprised if I could accurately drive the 335 to 2500fps w/o leading. I have not received the bullets yet so I cannot post any results, but following his advice worked very well in a 44mag w/ cast.

How fast you can push a cast bullet w/o leading is a baited question, as it depends on many factors. The bore dia, the throat dia, the twist rate, how smooth the bore is, the pressure your load opperates at, the alloy hardness, bullet lube, bullet dia, and I'm probably forgetting something.

I totally agree that when the base of the bullet drops below the neck on a bottle neck round, acccuracy goes in the toilet. I don't know if it's a factor of the driving band obturating, but make sure your bullet base is level or higher than the base of the case neck.

The real question isn't so much at what velocity leading occurs, as a good bullet won't just start laying lead on the bore, but rather what velocity you can get reasonable velocity. I'd say as a rule of thumb, most centerfires with a good barrel/chamber and a good cast bullet can achieve fine acccuracy up to 2200 fps. Some will produce fine accuracy up to 2400 fps, but you might have to put alot of effort into finding loads that shoot at that speed. Beyond 2400 fps, that IMHO is graduate level cast bullet shooting. Sure some guys get great accuracy at 2700 fps, but they generally have purpose built guns and molds, and taylor how they cast, lube and size the bullet to the gun.

To start with, clean the barrel to bare metal. Copper fouling will play hell with cast bullets, so start with a clean page, er barrel. I'd go with existing data for jacketed bullets at the velocity you are after. Try and stick with slower powders that will fill the case, though sometimes the faster powders will show better accuracy.

Hope this helps.

Concerning powders, right now I have been playing with Reloader 7 and IMR 4198. Based upon your suggestion, I think I will try the other end of the burning rate spectrum. I have tried H414 in my 416 Rem Mag and attained 2150 fps with 350 grain jacketed bullets. This may work well with the cast bullets as well. Thank you for your input.

I have posted this data before but I have a 350gn GC lino bullet at 2365fps from 74gn Varget giving me 1 in 50yd groups with aperture sight from my 404. The same bullet over 63gn H4350 for 1900fps gave me a .33in group. HT 380gn GC bullet over 80gn Varget for 2480fps gave 2in groups but droping the charge to 79 gave 2465fps and 1.35in group. None of these loads showed any leading. It is the pressure of a load causing plasticity that causes leading, rather than velocity so look to the pressure of your load being about 10% below plastic deformation. There is a lot more to top level cast bullet shooting than meets the eye although reasonably accurate practice loads are not that difficult to develope. At the moment I am playing with a 7mm bullet That I nose size to .275 then size the drive bands to .2855 then re-size the rear drive band to .2845. Lots of permutations to the game if you want to go past 'reasonable' and 'practice'.

Von Gruff.

quote:

He suggested filling the case w/ 4831 and seating the bullets no deeper than the length of the case neck. The slower powder decreases both the pressure and possible pressure spike.

If I did that with my .404J, I get about 2450fps and one heck of a lot of leading. IMO, it would be better using a light charge of 4759 or something like it and use a poly fibre fill.

In my CZ 416 Rigby, I find 125 grains of AA8700- with the RCBS 350-grain flatnose to be very accurate at 2200 FPS. Bullet sized .417", BNH 21.

I used the RCBS gas-checked 350-grain bullet in a Ruger No. 1 in .416 Rigby with close to an inch accuracy at 100 yards propelled by about 52 grains XMP5744 at 2,100 fps.

Thank you for your help. It doesn't seem there is a concensus concerning cast bullets in the larger bores. I would like to drive each of the bullets 2000-2200 fps with decent accuracy. I can get the velocity easy enough just not the accuracy I was hoping for. Anything close to an inch at 50 yards would be fine.

BB This is what my 404 did at 55yds and aperture sight. 2416fps for 1.1 inches ADI 2209 is H4350

Can get the same accuracy from non HT bullet at 2365 but better at 1900. Best thing about this load is that it duplicates the 400gn Woodleigh for energy for recoil recovery practice. The 350gn weight shown is actually 370 in the HT alloy ( 90%/ww 10%lino) from a custom Hoch mould to my own desigh.

Von Gruff.

Von Gruff,
Thank you for the data. These are the kind of groups I am looking for. You have used a large volume of slow powder. I do think filling the case makes a difference. You don't have the powder slushing around. I beleive my next set of loads will be with a slower powder.

boolit fit is most of getting great groups clint

quote:

Originally posted by clintsfolly:
boolit fit is most of getting great groups clint

That is why I designed my own mould. I wanted it to load to the same OAL as a Woodleigh so this set the length from front of crimp groove to meplat. The meplat of .2 radiused out to exact bore dia over just .25. Drive bands to be Groove dia +1 thou and grease groove to be bore dia. Heel cut for 44 cal GC and sent a bore slug with the data which was for a 350gn bullet cast in lino. ( It is about 370gn in the HT blended alloy) Have a mould that drops a bullet only a 1/4 - 1/2 thou over size for minimal sizing and so with a properly cast ( as in correct temp for the alloy being used) bullet, this all has an effect on the accuracy obtainable. Fun and burned powder increases proportionally. Aint life grand??

Von Gruff.