260Rem IMR 4451 Load Data confusion

[jlficken]

I formed some brass using Winchester 308Win brass to try out with my new rifle that has a 23" barrel.

The attached day from Hodgdon says 39.0gr is max so I stopped at 38.0gr in testing. There were no pressure signs but the 140gr Hornady BTHP was going really slow at 2375fps.

I'm looking. Now and see people using 41.5gr+ with this powder and a 140gr bullet so I'm confused.

I always thought Hodgdon data was MAX when they said Max as it sure is for 308Win and Varget but have they backed off now?

Should I just skip up to 39.0gr and work my way up to 41gr+?

It shot really well with 38.0gr but 2375fps is just really slow.

 

[cruze5]

my Tikka accuracy load is 42.3 grains of 4451 @ 2.825
speeds were with a hornady 140 projectile
2712
2713
2723
2717

very accurate load... just check the primers to see if they flatten... and the bolt when it starts to stick!

 

[Steel head]

I was at 43.9 grains with 140’s with a long oal in roomy Winchester brass and long throat chamber.
2850ish.

 

[jlficken]

I find it crazy that the Hodgdon data is so low.

I think I'll step up to 39.0 and then go in .5gr grain increments until I get to 41.0gr and then work up in .3gr increments from there.

Thanks for the info!

 

[Steel head]

I find it crazy that the Hodgdon data is so low.

I think I'll step up to 39.0 and then go in .5gr grain increments until I get to 41.0gr and then work up in .3gr increments from there.

Thanks for the info!

In their chamber that’s what they got.
It’s up to you to find out what your gun likes.

 

[FCS]

I find it crazy that the Hodgdon data is so low.

I think I'll step up to 39.0 and then go in .5gr grain increments until I get to 41.0gr and then work up in .3gr increments from there.

Thanks for the info!

Which 140 bullet are you using?

140 Partition is long for weight with more bearing surface, shorter ogive radius so deeper in case also. Bullet weight is only part of the equation.

 

[jlficken]

Which 140 bullet are you using?

140 Partition is long for weight with more bearing surface, shorter ogive radius so deeper in case also. Bullet weight is only part of the equation.

It's a Hornady 140gr BTHP so yeah it very well could just be the fact their data uses that Nosler bullet for the 140gr data.

Looking at the 142gr SMK that very well could be it considering their Starting and Maximum loads are 2.5gr *higher* than with the Nosler.

 

[FLIGHT762]

There's no confusion. You're using a Hornady 140 thin jacketed bullet and using loading data for a Nosler 140 Partition. Two very different bullets.

*EDIT* I see you found data for the 142 Sierra. That data will be closer to your Hornady bullet than the Nosler Partition.

 

[jlficken]

There's no confusion. You're using a Hornady 140 thin jacketed bullet and using loading data for a Nosler 140 Partition. Two very different bullets.

I realize that now. I just hadn't seen that kind of difference in any Hornady manual where they group the bullets by weight and they all show the same load data.

 

[SDBguy95]

my Tikka accuracy load is 42.3 grains of 4451 @ 2.825
speeds were with a hornady 140 projectile
2712
2713
2723
2717

very accurate load... just check the primers to see if they flatten... and the bolt when it starts to stick!

What Tikka are you running? Im going to start using 4451 for my .260 Tac A1. I really dont love working up loads, wondering what you run so I may hace a starting point.

 

[918v]

H uses Remington cases. They have less capacity than Winchester 308 cases. So you get more pressure and velocity per grain.

 

[cruze5]

What Tikka are you running? Im going to start using 4451 for my .260 Tac A1. I really dont love working up loads, wondering what you run so I may hace a starting point.

Tikka ctr stainless 20” https://www.eurooptic.com/JRTXC321S-Tikka-Tikka-T3x-CTR-260-Rem-S-S-200--barrel-MPN-JR.aspx