110BA .338 Lapua Mag & Hornady COAL tool

[Ole Silver]

Hello Everyone,

I'm new to the forum and look forward spending time here.

I am getting some strange results with the Hornady COAL tool & modified case.

When I move the pill forward, I am getting some resistance at about 3.630 COAL.
If I apply just a little more pressure, the pill moves forward and hits the lands hard at 3.760 COAL.

I ran the Tubb's final finish through at the range meticulous cleaning and many hours at the range hoping it might clean up, but I am observing the same thing.

Has anyone else seen this?

It seems that 3.630 is short and 3.760 is long.

The rifle shoots well with no pressure signs when ammo is rolled to the short measurement.

I get pressure signs and heavy bolt lift when rolled to the long side and the rifle shoots like crap.

I have heard that these rifles prefer a long jump.

Lapua brass. FL resized with shoulder pushed back about .002
Cases trimmed to 2.714
300g SMK's & Scenars
Win Large Rifle Magnum primers.

Using H1000, IMR4350, Retumbo & N560 with weights according to the books.

I'm just scratching my head here.

Thanks in advance for your responses.

I'm Happy to be a new member & hope to contribute.

Ole Silver

[sharpshooter]

Check your modified case for neck size. A common problem with this system is the neck on the case is expanded for the bullet to slide and it is too large to fit correctly in the chamber. Subsequently the case is inserted short, and it seems the freebore is extremely long, because of a false reading.

[Ole Silver]

Sharpshooter,

Thanks for the heads up on the neck size. I just went to my bench and checked and it seems that the modified case fits OK. I blackened the neck and inserted into the chamber with force and it came out clean. The modified case neck is at .370 & loaded case neck is at .367.

I blackened a SMK300 & inserted with the tool and pressured it to the lands and measured 3.760. I am observing marks on the pill where it drags through the chamber before it hits the lands, just one area about 1/4 inch wide.

I'm thinking I may need to get the chamber/throat/neck polished.

Thanks,

Ole Silver