Light Bullet Seating

[Huntslow]

I have a .243 on a Mauser action. Barrel is a 10 twist and chamber is throated for Berger 108 grain. It shoots well but I want to use it with "varmint" bullets. A friend passed away and his wife gave me about 1,200 75 grain hollow points. I can't "reach" the lands with the bullet in the case. What would be the minimum amount of bullet seating that is workable? So far I have only gotten to about .3 inch in the case, but accuracy has gotten better with each "additional" .05 of OAL.

Thanks

 

[VinceMule]

Much depends on which 75g HP you have as there is a lot of difference between a Sierra and Hornady Hp. I had a 75g Speer hp blow up on a hip joint of a coyote, so those became chuck and jackrabbit bullets.

All of these bullets like to be seated close to the lands, so you have a catch-22. Chances are, that the barrel has some wear on it being a 10 twist with the leade being as long as it is. You may be close to the end of the barrel's life. In this case, other bullets with more bearing surface will shoot better in a long, worn throat.

75g Sierras will shoot well with some jump. Another option of course is to sell the bullets and buy the 85g Sierra spt that is a flat base with some bearing surface. 90g Speer is another option, and any 100g flat base should shoot very, very well. In my well worn Rem 700, I have to shoot a 95g SST, and it does a job near and far, coyotes to deer.

With the 75g Sierra's, IMR 4064 with a federal 210 has served me well over the years on coyotes up to and including the 80g bullets. I then went to Win 760 or 4350 for the heavier bullets.

If you are using the rifle as a repeater, I would want .100 of bullet in the case.

243 Winchesters are NOT easy on throats.

Good luck!

 

[Huntslow]

VinceMule - Thanks. They are 75 gr Speer and will be used for groundhogs. I will try .200 and then .100 and see how that goes

 

[lancetkenyon]

Don't worry about how much jump to lands you have. The 75s will never reach the lands.

I am just surprised you are shooting a 108 Berger well in a 1:10".

 

[VinceMule]

Lance, I think that he must have been using the example of the 105 as having a long leade.

 

[Huntslow]

Just checked. My first barrel was 10 twist and the current is 8.5. Shouldn't make a difference in bullet seating depth

 

[Huntslow]

I just realized that shooting out a barrel is just a way to keep up with bullet technology!

 

[MagnumManiac]

Well, I had this discussion many moons ago about how much bullet NEEDS to be in the case neck.
Many shooting acquaintances were adamant that whatever calibre was in question was what was minimum for accuracy…
I seated bullets further and further out until I had .100" of bullet shank in the neck, up until this point, accuracy improved with the 2 75g .257" bullets in a custom 25-06. Bullets were Sierra and Australian brand called Taipan.
These acquaintances were perplexed as I did the same with a 308 using 155g PALMA bullets, accuracy was excellent right to the point of .100" in the case, where I stopped again.
With less shank, runout was noticeably bad.
Anyway, seat them however long you want and be happy!

Cheers.

 

[Rflshootr]

Much depends on which 75g HP you have as there is a lot of difference between a Sierra and Hornady Hp. I had a 75g Speer hp blow up on a hip joint of a coyote, so those became chuck and jackrabbit bullets.

Why did ya shoot it in the hip???

 

[VinceMule]

the coyote was circling us at a fast trot at a distance. My leade was off.