Coal gets longer and longer

[Chesterrose79]

I need help from the wealth of knowledge in this community. I have a friend who has 3 tikka t-3x's 300win mag that all have the same problem. I have quite a bit of experience with reloading and am bamboozled with this one.

I load a round with the bullet seated quite far into the case and we'll bow magazine length. Measure the base to ojive, rack it into the chamber to mimic a hunting scenario and then carefully eject the round and then measure the base to ojive and it always grows up to .005". Sometimes less. I've tried everything from using a bushing that gives it an ungodly amount of neck tention and it still moves.
I've taken the loaded round and it drops into the chamber with ease and falls out so it's not catching on anything. I took a marker and marked up the bullet to see if there is any scratch marks and nothing. I don't know what it could be. Also tried 3 different types of bullets and 3 different weights.
Could be tight chamber but would the bullet not fall into the chamber and out of the chamber if that was the case?

 

[GimpyPaw]

Try it again with a thin coating of case lube on the bullet.

 

[waveslayer]

Could be not consistent measuring it.

 

[Carlos88]

Neck tension may only be .001-.002 and anywhere in between.

 

[Muddyboots]

Try a factory round as a baseline.

 

[Bob Wright]

-Could you be measuring over a spent primer?
-If brass is any raised edges from extractor / burrs that can give you false readings. Head can be lightly sanded on a flat surface to check for raised edge
- zero your calipers to whatever ogive device measuring tool. My Hornady stuff needs to be loosened and retightened when calipers are closed with a little pressure. Then zeroed again.

Good luck.

 

[Ol' Red]

Muddy boots mentioned a factory round and I would agree that is a good baseline. Bob Wright had a good point about an extractor burr causing a false reading. I would mark an entire cartridge and chamber it. Look for any marks on the case or bullet after extraction.

 

[xsn10s]

That's unusual. My thinking is either the bullet is either jamming the lands and getting slightly pulled out on extraction or the inertia from yanking the bolt back. Both seem far fetched. Try coating the bullet from a non chambered round with a black marker and chamber it to see if it's contacting the lands.

 

[FEENIX]

I need help from the wealth of knowledge in this community. I have a friend who has 3 tikka t-3x's 300win mag that all have the same problem. I have quite a bit of experience with reloading and am bamboozled with this one.

I load a round with the bullet seated quite far into the case and we'll bow magazine length. Measure the base to ojive, rack it into the chamber to mimic a hunting scenario and then carefully eject the round and then measure the base to ojive and it always grows up to .005". Sometimes less. I've tried everything from using a bushing that gives it an ungodly amount of neck tention and it still moves.
I've taken the loaded round and it drops into the chamber with ease and falls out so it's not catching on anything. I took a marker and marked up the bullet to see if there is any scratch marks and nothing. I don't know what it could be. Also tried 3 different types of bullets and 3 different weights.
Could be tight chamber but would the bullet not fall into the chamber and out of the chamber if that was the case?

"I" find it hard to believe all 3 have the same problem. Try cleaning the inside of the neck really well (degrease, copper brush), load (no powder, no primer), and seat bullet .015-.020" off the lands, and with neck tension at .002" and re-do your test/measurements.

 

[Chesterrose79]

I tried it with no primers in and the bushing I used made it really tough to seat. It was .328. Tried with lube as wel. When extracting it was done gently.

 

[Chesterrose79]

I tried it with no primers in and the bushing I used made it really tough to seat. It was .328. Tried with lube as wel. When extracting it was done gently. Cou

Try a factory round as a baseline.

tried sako factory round and still does it.

 

[Chesterrose79]

I have a tikka 7mm rm that I tried this on and bullet didn't move.

 

[xsn10s]

My guess is the loads are jamming on something. Either the lands or really bad build up in the throat.

 

[FEENIX]

I tried it with no primers in and the bushing I used made it really tough to seat. It was .328. Tried with lube as wel. When extracting it was done gently.

What's the OD on the neck?

tried sako factory round and still does it.

In all 3 rifles?