Does any one have ideas suggestions.

I purchased a new 375 H&H Ruger No1. So far accuracy hasn't been great, and I suspected it may be me.

Recently I decided to purchase a bullet mold from LBT and after reading the instructions for measuring the throat, neck and leade, I made a soft lead slug of .380 and pushed that into the throat.
I was surprised to find it didn't come out round, acroos 2 grooves it measured .376, the next pair of grooves meased .3765 and the last pair measured .377.

Short of replacing the barrel, does anyone have suggestions?

Thanks

It is kinda hard to make precision but out of round holes. Try checking your barrel 3 or 4 more times until you get the technique right.

How did you measure the slug?

quote:

Originally posted by x-rings:
Does any one have ideas suggestions.

I purchased a new 375 H&H Ruger No1. So far accuracy hasn't been great, and I suspected it may be me.

Recently I decided to purchase a bullet mold from LBT and after reading the instructions for measuring the throat, neck and leade, I made a soft lead slug of .380 and pushed that into the throat.
I was surprised to find it didn't come out round, acroos 2 grooves it measured .376, the next pair of grooves meased .3765 and the last pair measured .377.

Short of replacing the barrel, does anyone have suggestions?

Thanks

That sounds like a possible technique issue. Make five measurements and take an average.

Thanks for the feed back.

I made a tapered slug that went from .379 up to .380.

I measured this at several locations and took the average, then forced it into the throat using plenty of lube, once the slug had entered about .5", I knocked it out from the muzzle end.

As near as I could manage, I measured across the middle of each groove, I tried this at several points along the groove, the results were the same each time I measured the groove.

One thought that occured to me was maybe the slug was out of round to start with, but I'm not sure. Would it be forced round if driven into a round barrel or would it stay out of round?

I'm going to re check using some cast projectiles and see what results I get.

thanks

You can distort a lead slug just in how you remove it. Pour a cast.

Does your Ruger #1 have a "micro-groove" barrel?
Some did as did the 458 Win. and 45-70 #1. Really hard to get an accurate reading on a micro-groove slug.

What did you use to measure the slug? Micrometer or caliper?

quote:

Originally posted by srose:
What did you use to measure the slug? Micrometer or caliper?

Or a Toolmaker's scope which is what I have to measure anything that close that I can fit on the table. I'm going to throw out the fifty millionths number again. My little microscope can measure a part down to .00005"