How much freebore for Hammers?

Koda

Koda

Hammer Time Executive member
I had a custom 7 twist 25-06ai built to shoot the heavy hammers. My guess is the smith didnt throat the chamber long. How much velocity will I lose if I seat about .020" off the lands? ...the bullet will protrude deep inside the case reducing case volume and potential for case "donuts" (so I hear).
left bullet and center show (about) where I can seat about .020" off the lands. Right bullet shows about where ideally the bullet should be seated. There is about .165" difference... so I would need to have the freebore reamed out by about that much.
127gn HHT shown.

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Gday koda
Shoot enough & you’ll get your freebore 🤣🤣
& donuts I’ll have the jam filled ones 🤪

Seriously now

@Mountainman is this possible to ream to that Serengeti 🤷‍♂️ or what’s the best option

I’ve had a few that cram the case like that & go a faster powder if you reach case capacity after tapping rolling while gradually seating the pill deeper
& all seemed to work out but not ideal & maybe that’s why I like the midweight pills 🤣

Others will give better advice
Cheers
 
Koda If he is going to ream .1 might as well go to the .165 imo don’t short change yourself

I’ve got no worries with those longer pills as long as not to long

if you have real long pills regardless of brand or makeup eg c&c or mono I believe a new thought process may apply but let’s leave that for another time as not to derail & I better not leave you hanging your 127 pill is ok

Cheers
 
Farleg said:
Koda If he is going to ream .1 might as well go to the .165 imo don’t short change yourself

I’ve got no worries with those longer pills as long as not to long

if you have real long pills regardless of brand or makeup eg c&c or mono I believe a new thought process may apply but let’s leave that for another time as not to derail & I better not leave you hanging your 127 pill is ok

Cheers
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^^^^^^^^^^^^^^This right here^^^^^^^^^^^^^
 
Koda,
My vote is go with the longer freebore. I've had to re-throat 2 of my cartridges (chambers) due to the increased length of the copper bullets. As Mountainman and Butterbean said, longer jump is not really an issue with Hammers. Getting into or too close to the lands can be!
Just make sure your rifle will feed/cycle longer loaded cartridges smoothly.
 
sigh.... I waited over a year for the build and was so excited to start working with the rifle. I went with a fast twist to shoot the heavies so it makes no sense to compromise as long a it doesnt hurt lighter bullets.

I'll give my smith a call next week and get it back to him. Hopefully it doesnt take a long time to get thru his workload.

appreciate all the replies, the general consensus here is encouraging.
 
When you do a build, you want it to meet your expectations. I'm glad you are giving the smith a call. He should have asked you more questions, and it would have been done right the first time. It is hard to find a really good gunsmith these days. I'm lucky. When I had my 45/70 made into a 45/90 to shoot the 458, 404 grain Power Hammer, I brought in a sample so it would be throated properly. It is amazingly accurate. I would highly recommend that you load up what you want to run in your gun and take the round in so the smith understands what you are after. My smith told me that 75% of his work now is on AR platform guns.

Joe16 is jealous.
 
Not much help in this case, but one trick I picked up along the way is to give the Smith a dummy round (no powder, no primer) with the bullet seated where I want it along with the action.

Good way to eliminate confusion, and that way they can ensure the bolt closes on the round before the gun leaves the shop 👍
 
les said:
I'm glad you are giving the smith a call. He should have asked you more questions, and it would have been done right the first time. It is hard to find a really good gunsmith these days.
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Hes one of the best in my state, at least by his stellar reviews and reputation. I have confidence he will understand and ream the freebore...
I did tell him I wanted to shoot the heavies and even shared a link to the Hammer bullet, what I didn't do was send him a dummy round.
I had already sent him my rifle before I decided on the exact Hammer bullet, this is my first custom build rodeo. I will make a dummy round and assure it fits/feeds from my magazine and get it back to him and he will know exactly what to do.
 
A larger capacity case will normally have more velocity potential. I would use it the way it is.
 
left a message with my smith.
Working on seating a dummy round...

Does anyone have any guidance on where to seat the bullet for optimal velocity?
Seems like at some point this one can be seated too far out. Im thinking of seating to the middle drive valley (left) seems reasonable? Opinions?
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@Koda : My .270 Win or as @joe16 calls it the .270 Thor thingy is in 700LA so magazine max COAL is 3.67. I set the COAL on the 156HH @3.63 which gives me reliable feed. I sent 2 rounds at 3.63 to Preferred Barrel with request for 0.010 off lands. After further discussions with PB, the freebore ended up being 0.290. My feeling is to max out the rifle magazine COAL and set freebore from that measurement. I felt strongly the 156HH would be special and it certainly is for the velocity and accuracy.

The 156HH still has 3 PDR bands in that ugly long neck that @joe16 calls it!😂 Case capacity is not diminished from these longer boolits so with right powder zoom zoom.

I discussed this with Steve quite a bit and the PDR's sitting out there have no detrimental effect. So my feeling is measure your magazine max COAL and make decision which bullet is most likely to be shot the most. I kind of feel I would prefer to max that bullet capability out.

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Muddyboots said:
My .270 Win or as @joe16 calls it the .270 Thor thingy is in 700LA so magazine max COAL is 3.67. I set the COAL on the 156HH @3.63 which gives me reliable feed.
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How did you measure your magazine max oal?

Mine is a 700, internal magazine that swings out. The follower measures 3.65" long. I figure thats probably max cartridge coal assuming it feeds fine.
 
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