My bullet will not get closer than 100 thou from lands

4

45C

CGN Ultra frequent flyer
Super GunNutz
Rating - 100%
160   0   0
Location
Canada
Hey
Can’t seat my bullet no closer to the lands than 100+ thous off the lands.

I measured my my OAL from the ogive using an Hornady comparator set and with the bullet just sitting in the case( not yet seated) I’m 100 off the lands.
Gun is a new Savage 110 ultra light( proof CFW barrel) chambered in 7PRC.
Berger VLD BT 180 grain.

Fixable? Or forget about it?

If I load them to hodgedons data I’m about 200 thous off the lands
 
It happens. I have a 9.3x57 where the 285 grain cast bullet will be circa 1/4" (.250") out of the case before the fat part of the bore rider bullet will hit the leads. Is another one, a 30-06, that, if using Hornady seating depth as given in their manual for that bullet, will be .020" JAMMED into the lands. Was pretty much "old days" to 1) load to fit and function from magazine, 2) to NOT be jammed on the lands, and 3) to seat about one caliber deep in the neck - leads one to fuss about concentricity of your load and bullet fit to the throat (free bore area) when not able to reach the lands. You will likely find different results with alternate shaped bullets? You describe a LOT of "jump" - more than I have encountered with jacketed bullets - maybe they will shoot accurately enough for you??

Go here - https://faq.weatherby.com/free-bore-on-weatherby-magnum-calibers - is a couple of those "boomers" showing over 3/4" of free-bore - and I am not so sure how that relates to amount of "bullet jump" - but was a technique used by Weatherby to reduce peak pressure, but to stay with high muzzle velocity.
 
Last edited:
45C said:
Hornady says max is 3.340
My gage is saying 3.587
Am I reading this wrong?

Yes, you are. Why are you measuring the end of the bullet and not the ogive (bearing surface)?

View attachment 663009
Click to expand...

45C said:
Berger
To get my bullet seated at 3.410 this is how much bullet is in the case.
I now have a jump of approximately.200?


View attachment 663012View attachment 663011
Click to expand...

Why don't you have the comparator on your caliper to measure the CBTO?

The ogive is the bearing surface that contacts the lands. Not the end of the bullet like you're measuring.
 
Last edited:
6MT said:
Why don't you have the comparator on your caliper to measure the CBTO?

The ogive is the bearing surface that contacts the lands. Not the end of the bullet like you're measuring.
Click to expand...

Should have done that before I panicked.
Didn’t realize the OAL would be that much different from bullet to bullet

I understand that the ogive contacts the lands, I was just using the OAL as a reference point.
 
Last edited:
So I may have made a mistake, not sure yet.

I made a modified case out of a piece of 1 time fired brass.
I think what’s happening is the case is not entering the chamber all the way.
I think that’s the issue
I’d buy a modified case, but can’t find one.
I’m going to remove some material from the outside of the case neck, to allow it to enter the chamber more freely.

Maybe the outside diameter of the case is too tight to just push in with the comparator?

Anyway I have some more checking to do.

Sorry for the drama.
 
Again sorry, but I’m glad I asked here, saved me a lot of grief.

Case wasn’t entering the chamber completely, thereby giving me an improper reading.
All good now.
 
45C said:
Again sorry, but I’m glad I asked here, saved me a lot of grief.

Case wasn’t entering the chamber completely, thereby giving me an improper reading.
All good now.
Click to expand...

Wow.
Sometimes it's the littlethings that mess you up.
 
That bullet will need to be seated out far relative to most other bullets. I have an old 7X57 sporter in which I use 175 gr RN bullets (and am happy to), in which any available "pointier" 140 gr bullet is very far form the lands.

If it doesn't shoot accurately and/or you can't get a replacement barrel/firearm, changing bullets can be an option.
 
Andy said:
That bullet will need to be seated out far relative to most other bullets. I have an old 7X57 sporter in which I use 175 gr RN bullets (and am happy to), in which any available "pointier" 140 gr bullet is very far form the lands.

If it doesn't shoot accurately and/or you can't get a replacement barrel/firearm, changing bullets can be an option.
Click to expand...
It’s all good now.
The homemade modified case wouldn’t completely insert due to the outside diameter of the casemouth being a touch too big.
I sanded it down so it could completely chamber.

If you have an Hornady modified case, measure the outside diameter of the case mouth and you’ll find that it’s smaller than a FL sized case mouth.
 
Jahnj0584 said:
I cut it twice and its still too short!
Click to expand...

It took me years before I understood what my father was inferring about my carpentry skills when he said "no matter how many times I cut something,it will still be too short"

Regarding the bullet seating depth,I found the Hornady OAL gauge and modified cases to be very efficient at determining seating depths for most of my rifles.The exception for me would be the Weatherby calibers ( at least my 7mm Weatherby ),where the bullet can be pushed right out of the modified case without contacting the rifling.
 
Last edited:
45C said:
Yup, good thing I got it straightened out.

Who’d of thought the small difference between the diameter of the case mouths was the issue, eh.
Click to expand...

You might want to confirm that after seating a bullet, there is clearance in the neck area to allow bullet release to be safe. If tight, outside neck turning will resolve this issue.

Enjoy the barrel.

Jerry
 
You must log in or register to reply here.
Back
Top Bottom