RCBS mold 30-150-FN157 grains Sized .310", gas check ?

[lonewolf5347]

I had a chance to shoot these cast bullets today
My powder was IMR 3031
I tried a few different charges
28.0 gr.
28.5
29.0 grain
I did not have any barrel leading but would like to ask what is the best C.O.A.L.
just touching the lands?
I did have one round a little to long the lead bullet was a little to hard to chamber so I did extract the round from the chamber seem the bullet stayed in the land and the brass came out on it own.
I did have a cleaning rod with me so the cast bullet drop out of the barrel without any problems.
I seem not to have any problems with my C.O.A.L. at
2.495
2.524 was the problem
I shoot .005 of the lands with my 38-55
I wonder if .310 is to large no signs of spike pressure :is it o.k. to see a light mark on the lead bullet when chambered?
I tried seating the bullet a little deeper but it seem all the time to pick up a imprint of the lands on the shoulder of the bullet
I shot .308 dia; no problems it may just have a tight bore for .310 bullets

[Ben]

If you're shooting .308" dia. cast bullets in a .308" bore and having success, you are one of a very few that is able to do that successfully. More often, .310" and even .311" cast bullets are fired in .308" bores.

Your question : " Is it o.k. to see a light mark on the lead bullet when chambered?"

Many of us work hard to be certain we ARE seeing that.

When you say " shoulder of the bullet " , are you speaking of the 1st drive band on the bullet ?

Ben

[lonewolf5347]

just above the seating band

[Ben]

Is this the drive band just forward of the crimp ring.

[lonewolf5347]

yes that is correct

[Ben]

OK, that lets us know exactly where your contact is. Your other terms of shoulder of the bullet and seating band don't tell us much.

If that is a problem with the lands contacting the 1st band , simply seat a bit deeper.

[lonewolf5347]

http://i15.photobucket.com/albums/a380/lonewolf5347/ca3ca178-6f93-43ae-b7d5-a53cd9054664_zps8516f711.jpg (http://s15.photobucket.com/user/lonewolf5347/media/ca3ca178-6f93-43ae-b7d5-a53cd9054664_zps8516f711.jpg.html)

this is a different bullet but the red marks are were the lands cut into the cast
I tried to seat the bullet deeper but still run into the same marks

[Ben]

Ok, those marks are on the " Nose " of the bullet.

I now better understand exactly what your problem is.
It is a problem with the diameter of the nose of your particular cast bullet not necessarily a problem with your rifle or loading procedures.

Take a good micrometer and measure the nose dia. on your bullets and report back.

Did you ever specify which rifle and caliber of rifle you're shooting these cast bullets out of ?

When it comes to " nose riding bullets ", a lot of .30 cal. rifles won't tolerate a bullet with a nose over .300" in dia. Others will lightly engrave the nose if it measures .301" and still chamber OK. Some won't chamber at all with a .302" dia. nose.

If your loaded rounds chamber smoothly or chamber with VERY light resistance and makes light marks on the nose ignore it, load them and shoot them. If it chambers hard or won't chamber at all, you may have to move to a completely different cast bullet design.

I don't know that you'd want to get into this as a " remedy " for your problem, but this is what I do when I run into the problem you describe :

http://castboolits.gunloads.com/showthread.php?225875-Is-your-nose-too-big

Ben

[lonewolf5347]

measure the nose dia
http://i15.photobucket.com/albums/a380/lonewolf5347/castboolts001_zpsf9dcdf81.jpg (http://s15.photobucket.com/user/lonewolf5347/media/castboolts001_zpsf9dcdf81.jpg.html)
Bullet on the left measure nose .299.5 at 308 sized Lyman
Bullet on the Right .303 at 310. dia RCBS
Rifle marlin 30-30

[Ben]

Looks like you have two different bullet styles in the photo.

Does the one with a .299" nose diameter chamber OK ?

Can you determine a difference in resistance felt when you try and chamber the two different bullets ?

Ben

[lonewolf5347]

left side .299 chamber the best but it seem to pick up a light impression from the lands on the nose of the bullet at a C.O.AL. 2.530

[Ben]

I wouldn't worry about it. I'd shoot those ! !

Remember , we said that light marks on the nose are desirable.

You just don't want so much resistance that you're unable to chamber a loaded round smoothly and eject the same loaded round smoothly.

Ben

[lonewolf5347]

I did solve the problem
I measured the brass I loaded at 2.038
I decided to trim down the brass to 2.032
I then loaded the larger dia:.310 2.500
and no more marks from the lands on the nose of the bullet

[Ben]

All is well that ends well.

Ben

[lonewolf5347]

thank you

[Ben]

You're very welcome.

Good Shooting,
Ben

[runfiverun]

holy cow,,, i go through so many pains to make my nose engrave lightly when chambered and then eject a loaded round without a hitch, it ain't funny.

[Ben]

runfiverun

I think based on his remarks that it was hard for him to know what was just enough land engagement on the nose and what might be excessive engagement.

Ben