Extra long bullets, 128g .257 Hammer Hunter

[Koda_]

I'm getting a new barrel installed on my 25-06 with a faster twist to handle higher BC bullets and while reviewing one of the bullets Im considering I noticed how long the bullet is, woah.... the .257cal 128g Hammer Hunter is 1.515" long and I wondered how far into the case are these seated?
Let me use a photo to help explain, below is a pic of a handload I developed for my old factory barrel using a 100g Barnes TTSX, that handload had a .050" jump to the lands. I'm still fairly new to handloading but have heard to not seat the bullet base past the lower shoulder junction.
Yes, Im aware that the ogive geometry of the Hammer bullets will be different but thats still a very long bullet. For reference the Barnes 100g TTSX shown is 1.192" long.
How deep can you seat the longer Hammer bullets?

 

[GLTaylor]

There are several options available:
First, you're correct. It's best to seat a bullet as you describe if possible. This minimizes bullet seating that reduces powder capacity. However. They'll still shoot fine with more bullet down into the case. You just may have to settle for less powder-maybe.
The second thing - is, since you are re-barreling, you can have your smith chamber the new barrel with a deeper throat to have more bullet protruding - if your action can handle the additional cartridge length and still feed smoothly.
Make up a dummy round with the new longer bullet seated as you prefer. See if it will even fit in your magazine and if so, will it feed?
You may have to compromise. A bit longer cartridge, but less intrusion into your powder space.

 

[lancetkenyon]

If you cut your FB for the 128 HH, just realize everything else will have a big jump to lands if you switch bullets.

 

[Hugnot]

One long pointy bullet! Be prepared for a quick twist, like 1-7.

This is the Miller Sg estimator. Note that temps are 78 degrees, 3000 fps, & Sg is 1.53. Should temps be colder or velocites be less, the estimated Sg might fall below 1.53. A Sg of 1.5 or more is recommended.



Very likely in addtion to having a big jump for shorter bullets should the chamber be cut for the 128's, certain lighter bullets designed for varmint shooting would blow up with the 7 twist. Seating the 128's to avoid contact with brass neck/shoulder might result in the rounds being too long to fit in magazine.

 

[Koda_]

There are several options available:
First, you're correct. It's best to seat a bullet as you describe if possible. This minimizes bullet seating that reduces powder capacity. However. They'll still shoot fine with more bullet down into the case. You just may have to settle for less powder-maybe.
The second thing - is, since you are re-barreling, you can have your smith chamber the new barrel with a deeper throat to have more bullet protruding - if your action can handle the additional cartridge length and still feed smoothly.
Make up a dummy round with the new longer bullet seated as you prefer. See if it will even fit in your magazine and if so, will it feed?
You may have to compromise. A bit longer cartridge, but less intrusion into your powder space.

This is good to know. Im glad I noticed this as I can consider a deeper throat but I dont want to limit my options of using lighter bullets down to 100g (like the photo). It could be that I leave the chamber throat standard length and compromise on the bullet and use a ligher Hammer like the 121g Hammer Hunter which is 1.35" long and ~should put the base around the lower shoulder junction which shouldnt be that bad to work with attaining good velocities. My smith has my rifle so I cant check the mag length but its a Rem 700 long action and has always had way more room in the mag for factory ammo.
It sounds like I have to decide how much I "really" want to use the heavier/longer bullets.

 

[Koda_]

One long pointy bullet! Be prepared for a quick twist, like 1-7.

This is the Miller Sg estimator. Note that temps are 78 degrees, 3000 fps, & Sg is 1.53. Should temps be colder or velocites be less, the estimated Sg might fall below 1.53. A Sg of 1.5 or more is recommended.

View attachment 388609

Very likely in addtion to having a big jump for shorter bullets should the chamber be cut for the 128's, certain lighter bullets designed for varmint shooting would blow up with the 7 twist. Seating the 128's to avoid contact with brass neck/shoulder might result in the rounds being too long to fit in magazine.

I'm ordering a 26inch 1-7 barrel. I'm not really interested in varmint hunting or lighter bullets less than 100g I wanted this barrel to shoot 100g and heavier. I don't recall the 100g Barnes being sensitive to extra jump but not certain how much that can be pushed.
It sounds like this is something I should ask my smith about but would be interested to learn more first... if I have to decide to compromise between a standard throat and limited to 100 to maybe 125g projectiles or a slightly longer throat and stay above maybe 115g projectiles. Im mostly interested in using Hammer bullets right now but also dont want to be limited to just one projectile companys offerings.

 

[Dmagna]

If u are getting a fast twist barrel get a long throat and improve the 25-06. Send them bad boys screaming.

 

[Koda_]

If u are getting a fast twist barrel get a long throat and improve the 25-06. Send them bad boys screaming.

Thats the plan. I just didnt know I might need a longer throat so now Im curious where the limitation will be on using lighter bullets.

 

[6.5saum/300rum]

I had almost the same idea as you this spring. I put together a 25-06 with a 24" 7 twist barrel to shoot the bigger hammers. I feel like the 110 and 121's are the best with this case. I like higher velocity when I'm shooting mono's so I never bought the 128's I think they would be perfect for a 257 weatherby. I thought my smith used a sammi reamer but I'm able to seat my bullets pretty long so maybe not. I'll try to double check and see what it is.

 

[Hard rock]

I had almost the same idea as you this spring. I put together a 25-06 with a 24" 7 twist barrel to shoot the bigger hammers. I feel like the 110 and 121's are the best with this case. I like higher velocity when I'm shooting mono's so I never bought the 128's I think they would be perfect for a 257 weatherby. I thought my smith used a sammi reamer but I'm able to seat my bullets pretty long so maybe not. I'll try to double check and see what it is.

You need too take a look at the 117 gr Hammers , that bullet is all you will ever need in the 25-06 . As far as throating you can split the difference so you can seat out farther and still take advantage of the lighter bullets ( Hammers) , you can't over spin a Hammer bullet , also they are not sensitive too jump , probably more forgiving than any other bullet I know of . I built a 25-284 last year specifically too shoot 90 gr and 117 gr Hammers , it's a 1-8 twist , I will not be shooting anything heavier in the 25 cal , if I need heavier I'll move up in cal . The 90 gr Hammer absolute moves out at 3874 fps with Rl19

 

[jacob_strass]

I have a 25 creedmoor 26" long 1:7" twist, I have shot the 117 Absolute Hammer up over 3200 fps and I'm hoping to get a little more out of it. I'm also trying the 125 Hammer Hunter and have a ladder loaded but have not had a chance to get to test them. I'm hoping to get that 125 close to 3100. If you check the BC values between the 128, 125, and 121 it doesn't really pay to go to the 128. I'd try between the 117, 121, and 125 and see what you like best.