I worked up a couple of loads and I notice slight ejector marks on new brass. I measured the brass and realized it was .007 longer than recommend trim length. The ejector marks are hard to see however, I thought this maybe cause with the cases to long.

Thanks

Steve

quote:

Can brass thats to long, cause high pressure??

Yes roger

OH YEA !.

Shoot Straight Know Your Target . ...

Depends on how much to long is. As Max length spec is .010 over "trim to" (and your only at .007) than that is not your problem.
Once you exceed Max length, than you can run into a "pinching" condition, where the case mouth runs into the mouth clearance cut in the chamber.
If the case mouth is pinching the bullet, it can't release it and pressures will spike quite high. IOW it won't be a slight extractor marks you'll be looking at.

Tailgunner

I'm shooting a .378 Weatherby Mag. and I just had a new Shilen barrel installed. I shot one load with 112 grain of powder and another with 111 grain of powder and the ejector marks are about the same. Both loads are with .270 grain Barnes TSX and are below max by 3 and 4 grain.
So I just figured the brass may have been to long however the max length for the brass is 2.913.

What is the chance I have a lott of soft brass? Maybe this will chance if I use different brass.

Thanks

Steve

Did the reamer have a "normal" or a Weatherby throat/freebore grind? The reason I ask is that Weatherby load data depends on having lots of freebore to keep the pressures down.
Personaly I'd contact the gunsmith that did the work, and get his opinion on what your seeing. He may have / may need to do a chamber cast to verify internal dimentions.

I don't load Weatherby's (I had a bad experance with their customer service dept, and refuse to own anything with their name on it), and am away from my load data sources, so I don't know where you are with that powder charge.

Tailgunner

When I picked up the rifle I asked him that same very question about the freebore. He showed me the reamer and It looked like about 1/2" of freebore but I'm not sure since I'm not a gunsmith. Thanks for the suggestion and help.

What do you think about the cases being to soft?

Steve

It could be that your rifle is "TIGHT" and develops more pressure. Your best bet is to back down a little. A chronograph can tell you a lot here.
Put magic marker all over the bullet and end of the brass, chamber a dummy round and remove it. See if the bullet is touching the rifling or if the end of the brass is jamming into the ball seat.
Freebore is important in the Weatherby's or you can't load as hot. That can create a problem if you reduce a very slow powder below the starting loads. You can get the dreaded SEE effect. In that case a faster powder needs to be used.
Don't take anything for granted, find the problem!
It has been a long time but it seems to me the Weatherby's had a 3/4" freebore. Does anyone know?

Gentlemen

I just checked the freebore on this new barrel and it is .800". Next I'll try the black magic marker trick and find out if I'm touching anywhere and then shoot it through the chronogragh.

Thanks

Steve

Most chambers about about .030 to .o40 longer than the brass trim length. While it is possible to have the case neck extendeing into the throat causing high pressure it isn't likely.
Even if you get a few thousandths too long the case will shorten when fired.
Right now I am working with a 6.5X53R Dutch Mannnlicher made by Steyr, the same folks that made the Mannlicher-Schoenauer. The trim length for this round is given as 2.110. The chamber is about 2.150 long and loaded brass actually impinges at the neck when trimmed to 2.152.
I trim to 2.150. When fired it shortens to 2.148 to 2.145.
If you suspect over length breass is causeing the problem it probably isn't, but you can prove it isn't two ways. The easy way is trim your cases. A little more involved way is to measure the actual length of your chamber.

It's unlikely that you are experiencing any interference. Recommended trim lengths have little to do with the mfr.'s process, except that the throat will always be longer. If you want to know what you have, Sinclair has a piece that fits inside of a shortened case neck, and it is checked with a caliper after chambering. Keeping your necks a few thousandths less will ensure adequate clearance.

quote:

Originally posted by Winchester 69:
...Sinclair has a piece that fits inside of a shortened case neck, and it is be checked with a caliper after chambering.

Sinclair calls it a "Case Length Gauge", and it allows you to measure the actual length of your chamber (how long brass can go before trimming is necessary). One of the more useful gadgets in reloading.

http://www.sinclairintl.com/cgi-bin/category.cgi?category=RESDTCL&type=store


Sadly, the caliber list is pretty limited, and in particular no .375 cal gauge is offered

- mike

quote:

Most chambers about about .030 to .o40 longer than the brass trim length. While it is possible to have the case neck extendeing into the throat causing high pressure it isn't likely.

This is a good statement. While I always trim to well under trim length, the casing a few thou over length isn't likely to cause a problem pinching the bullet!

quote:

Originally posted by vapodog:

quote:

Most chambers about about .030 to .o40 longer than the brass trim length. While it is possible to have the case neck extendeing into the throat causing high pressure it isn't likely.

This is a good statement. While I always trim to well under trim length, the casing a few thou over length isn't likely to cause a problem pinching the bullet!

Can't prove or disprove it one way or the other but .030" to .o40" IMHO can be significant especially with smaller capacity cases, with tight necks and fast burning powder. CAN IT HAPPEN ? Again the answer is YES, YES and No Maybees. It has happened. roger

"slight ejector marks on new brass"

When i first started loading for .270 and saw shiny marks on a area of brass i thought same thing, but turned out to have nothing to do with pressure.
was just normal marks from bolt/ejector closing/opening on cartridge.
Makes the same shiny mark on unfired rounds that are ejected