Testing UNSIZED bullets today???

[oldracer]

Well, an update on the earlier post about the unusual compression with the 45-70 loads, there seems to be absolutely NO differences in how the loads shoot!

Now on to the title of my post and this is about the very last thing I needed to see how the diameter of the bullet affected the shot spread. I had opened up my Lee 0.457 sizer die to 0.458 and they are shooting great with no leading or other issues since I did that. The barrels on all 3 of my rifles slugged out to 0.458 so I made the die opening slightly larger and group size dropped by about 30% on a calm day such as today in San Diego.

So, I figured I would try some unsized and as cast bullets which my Lee mold drops at 0.459 and see what happens. My God, the first 5 shots were all touching at 100 yards and at 200 yards, 3 were touching and the next 2 were about 1/2 inch to the right! This was with belled case mouths, 68gr Goex FFG powder and shooting on cross sticks on a bench! BOTH my Rolling Block and the limited edition Creedmoor Sharps from Cimarron grouped almost exactly the same! There was no lead in the barrels and they both wiped clean with several patches and some Ballistol. I am not sure if the larger bullets are the answer, but two of my guns sure seem to like them and the next outing I'll try again but just in case I plan to take the sizer and a Lee portable hand press to size them if necessary.

Anyone have ab experience with this idea?

[Chill Wills]

I would say shoot the largest size bullet your rifle chamber-brass case combo will allow in. Here is why. When the big red light comes on, what ever size the bullet is, it will bump up to fill the complete diameter available, regardless if it started full size as cast, sized down or sized down too small.

No point casting them big enough, sizing them down and then bumping them back up when you fire them. Some accuracy is lost with each change in size.

[Don McDowell]

Generally it's best to be at groove diameter to .001 or .002 over with the bullet diameter.
Some rifles with extra generous chambers are a little different and the bullet gets along a bit better the closer it comes to fitting the chamber.
You did the best thing by trying several diameters and seeing what worked the best.
The rifle will tell you what it wants , if you listen to it...

[nanuk]

Don, perhaps the rifle is already talking?

[Dan Cash]

I load BP for a .45-70 Shiloh and a Pedersolli with an as cast 550 gr. Hoch bullet. Works for me.

[otterdriver]

You must have been on Cloud 9 at the end of that shooting session. Thanks for telling us, there is some useful information for the novices such as I, among the forum.
Chris

[EDG]

>>>I am not sure if the larger bullets are the answer,<<<<

Based on my experience with 45-70s this IS the answer.
Accuracy with as cast bullets from .460 to .462 is better than you can hold.

[Chill Wills]

EGD you wrote:"Based on my experience with 45-70s this IS the answer.
Accuracy with as cast bullets from .460 to .462 is better than you can hold."

Yup! Which is the diameter range most well made 45 cal. BPCR moulds deliver bullets.
Every once in a while a very tight chamber will require a "smaller" bullet to fit in the chamber as a loaded round in the brass case. A rifle such as this can be extreamly accurate if everything else is well smithed. "Smaller", as in 0.459" or 0.458"

The great exception to this rule is bore diameter bullets such as paper patch bullets that ride the lands to center up when chambering and then bump up when fired. Knock-out accuracy can be had.
Creedmoor era match rifleman of the 1870's, both American breach-loaders and Irish ML team members used this system out to 1000yards with great accuracy.

[JeffinNZ]

And yet if I shoot as cast .377 boolits in my .38-303 they shoot terribly. Sized to .375 and it's near MOA.

[oldracer]

Well, very interesting comments from everyone. I plan to try the following ideas:

- Use an already cast bullet and lap one of my Lee molds slightly to open it to 0.460 which means the bullets might be a tad larger as all mine seem to swell slightly.

- Open up my Lee sizer die to 0.460 (it is 0.458 now) and run the new cast bullets through it so they will be uniform and rounded, etc.

- Load up some test loads and see what happens and if accuracy is as good as the unsized bullets at 0.459 then I'll open the other molds up also. This will take a few weeks so I'll report the results once I get testing completed.