Basic Rifle Bullet Seating

[alwaltr817]

Im having trouble getting 8MM Mauser with Nosler 180 G bullets to chamber in my rifle (k98). I have previously reloaded 150 G, bullets with no problems. It appears that this bullet, which is a bit longer than the 150s is slightly cocked as I see rifling marks on only one side of the bullet after test chambering. Deeper seating doesnt seem to make a different (in regard to chambering). I am using new RCBS dies with bullet seated to 3.250 OL. I do have an M die but have not used it because Noslers have a boat tail. Also I have not used lube on inside of neck (case was inside neck lubed during resizing). RCBS recommends that I have a custom bullet seating plug made up. I will do that, but how else can I ensure that these bullets go in straighter? I tightened down seater nut at each adjustment down. Any tips would be appreciated.....best all.....

 

[TonyD]

I've no experience with the 98 but I'd be a little worried about seeing rifling marks after just chambering a round. It should not engage the lands before firing. Even if you custom seat to the lands in should not be shoved into the rifling. I'd also find it hard to believe a bullet can be seated cocked at such an angle as to only receive marks on one side. I suggest that the very first thing you do is have the chamber checked by a competent 'smith.

 

[alwaltr817]

Thanks TonyD. Ive shoot may different factory loads with no problems. Bullet is definitely roughed up on one side. I' bring the gun in to my gunsmith this week. I've seated the Nosler 180 to what Nosler book says 3.250" (SAAMI). Im going to try a different case and very slightly bell out the mouth with my M die. If that doesnt work I'll get new custom seater plug for this particular bullet...Thanks again....

 

[Jarhead]

Have your smith measure the freebore of the chamber. This will tell you where the lands start. You need to get a bullet comparator to measure the cartridge length to the ogive of the bullet. Then set your seating depth around 5-8 thousandths less than the freebore measurement. DO NOT overseat your bullets.It is likley to cause pressure problems.
It seems that the ogive on your 180 gr bullet has a more blunt ogive than the 150 gr. You may find a bullet of the same weight with more of a long tapered shape.
Hope that helps and doesn't sound confusing.But definitly have it checked out!

 

[TonyD]

Are you certain that you're not seeing marks created by the bullet being dragged across the locking lugs during chambering and extraction? That would explain the marks only on one side. During extraction, the ejector and extractor are pushing the bullet to one side and drags against the side of the chamber, lugs, etc.

 

[Jarhead]

That could be Tony!