Inacurate .375 H&H

[Willy63]

My first cast bullet experience is horrible.  Loading veril smith 350 grain bullets with IMR 4831  from 70 to 76 grain.  Cant get the 375 tighter than 4" at 100 yards.  Same gun with nosler partitions was great.  Gun is tight scope is solid, bore is clean everything is great except accuracy.  got a load thats close using 71 grains but nothing great.  But at roughly 1900fps how can this be a good load. I hear great things about using cast but for now Im not sold.  Ballisticly that round is a rock.  Any suggestions???

[Leftoverdj]

Cast bullet problems are usually traceable to either bullet fit or bullet hardness. You need those bullets to fit the throat and you need them hard.

Without being able to measure your rifle, I'd say that if your bullets are not at least .377, there's your problem. A guick look in a loading manual suggests that your pressures are in the 35k range and that calls for heat treated bullets.

[Willy63]

Thanks for the help.  So the bullets are too soft for the rifle at those pressures??  Do they not get bit by the rifeling, or do they just fly in a non stable manner?  I think Im going back to cast bullets ;-)

[bgjohn]

Why shoot cast bullets at all?
JM

[Willy63]

Cause there $16 per hundred instead of $40 for 50ct.  I took a chance

[Leftoverdj]

Willy, this is very hard to do at long distance, but any rifle that shoots jacketed bullets well should be able to shoot cast bullets reasonably well, say under 2" at 100 yards. If you are paying 80 cents each for jacketed bullets, that's a powerful motivation. I cast my own, but not for .375, and never have more than a nickle a bullet in them.

Are your bullets gas checked? (That's a little copper disk on the base.) If they aren't, you are not going to be able to get anywhere close to 1900 fps with accuracy.

When the pressure is above the limits of your alloy, the bullet flows and deforms, and accuracy vanishes. The loads you mentioned generate more pressure than most alloys will take and it is not wise to reduce charges of IMR 4831 very much.

Shooting cast bullets takes some learning and some tinkering. Almost nobody gets good results right away, but when the cost difference is 75 cents a shot. it's worth putting some effort into it.

[carpediem]

You said you were using jacketed bullets with no problem.

In order to achieve optimum accuracy with cast bullets, among other things, you must clean your bore maticulously when you switch from jacketed to lead, and visa versa.  If you do not, you will find accuracy in both jacketed and lead will be degraded.

Kindest regards,

Carpediem

[swifty]

Why don't send a question to Veral Smith. His forum is just below and you can ask the Main man. From looking at the responces I think several would find it useful to read Veral's Book on cast bullet accuracy.
For starters, you can get an egg shapped fising weight ust a bit larger than the bore and slugg the barrel by driving the fishing weight down the barrel with a wooden dowell. Measure the weight or send it to veral with your order for a mould.
The main observation from your comments is that the amout of powder is too much for cast bullet shooting.

[Nobade]

I reckon you might want to slow that thing down a bit and clean all the copper fouling out of your bore before trying it again. Try some IMR 4759 or Accurate 5744 and follow their load recommendations. Shoot for about 1700-2000 fps and you'll have better luck. And of course fit the bullets to your rifle's throat.

[dave375hh]

Willy,
Conventional wisdom normally means .001 to .002 over bore dia. but not always. My Browning safari would shoot IC patterns with bullets sized .377.  I tried a GC 375449 sized .375 and got it down to two inches. I then seated them to just kiss the rifling and changed the load to 35.0 grs RL 7, Plus 21 grs of Win grex shotshell buffer as a filler and they shoot 1 1/4 to 1 1/2 5 shot groups. That's what I was looking for to practice with.  This rifle shoots just about any jacketed bullet into 3/4 inches all the time. The load came from the back of  Lyman manual #45 called "Loading the old ones" it's a load for a 38/55 not counting the Grex of course. Experimenting is what it's all about after all.

[sgtt]

What is your alloy?  I always thought that LBT molds were designed to use WW.  I would also consider H4895 and IMR3031 as alternative powders, although RL7 is hard to beat over all.  What lube are you using? I have had the best over all experience with the NRA formula.