RockyMtnMT
Official LRH Sponsor
We would rent the reamer as long as you are willing to use one of our smiths.
200 grain 6.5 revisited (Attention Elkaholic, and Hammer)
- Thread starter HARPERC
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- elkaholic rockymtnmt
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RockyMtnMT
Official LRH Sponsor
Yes, one of these days! I think it will be a bit easier to work with than the 6.5 UltraCat. Little shorter powder column and tougher brass. Although we have not tried ADG in the UltraCat. We still have one of our original UltraCats that just needs a stock. We might have to try it with ADG brass. Can't do too much experimenting with @HARPERC 's rifle, it will be worn out trying to see what we can make it do!
RockyMtnMT
Official LRH Sponsor
I will add one other thing.
This rifle is pretty heavy so recoil with the small PK is very little. As we worked up the 124's, the closer we got to 4000 fps the less the recoil got. It almost has none.
This rifle is pretty heavy so recoil with the small PK is very little. As we worked up the 124's, the closer we got to 4000 fps the less the recoil got. It almost has none.
codyadams
Well-Known Member
I would think a 6.5-.338 Norma Mag Improved would be even better, still have the Lapua/Peterson brass option, but an even shorter and more efficient powder column. Use that to push your 131 Hammer in a 7.5 twist, maybe hit 3900 with it? That would be pretty awesome as well.
HARPERC
Well-Known Member
This has all been an experiment for me, I've learned a bit each step. We used an action I had, starting today (without downplaying what we have) I would have got an action compatible with the bigger better designed cartridges. Steve was already there (reamers available for the Lapua/Norma) As it's come together, I don't know if we would squeeze more velocity out of it, but I've become more comfortable with the shorter powder column producing better ignition, burn, and perhaps less worry of pressure spikes.
Some exterior ballistic info, and terminal performance experiments to round out development.
Cody do you know the case capacity for the 6.5-.338 Norma? The faster twist hasn't shown to be a detriment in the mono's-what tips you toward the 131 over the 137.
HARPERC
Well-Known Member
This has all been an experiment for me, I've learned a bit each step. We used an action I had, starting today (without downplaying what we have) I would have got an action compatible with the bigger better designed cartridges. Steve was already there (reamers available for the Lapua/Norma) As it's come together, I don't know if we would squeeze more velocity out of it, but I've become more comfortable with the shorter powder column producing better ignition, burn, and perhaps less worry of pressure spikes.
Some exterior ballistic info, and terminal performance experiments to round out development.
Cody do you know the case capacity for the 6.5-.338 Norma? The faster twist hasn't shown to be a detriment in the mono's-what tips you toward the 131 over the 137.
codyadams
Well-Known Member
The 131 over the 137 simply because the 137 necessitates a 6.5 twist, not sure if the rather extreme twist would be deteimental to accuracy at extreme velocities. As far as capacity....not totally sure? I know West Texas Ordinance did a 7-300NM Improved, with a 30° shoulder, and capacity was 107 grains. Throw a 35-40° shoulder, take away some by going from .284 to .264, maybe do something with case taper, you may get 110 or so out of it? I think the main benefit over the 6.5 ultracat would be a less tempermental cartridge, due to case design, and it may be a lot easier to get a consistent load in such an extremly overbore cartridge. It would however, as you said, necessitate a different action, being that it is a wildcat with no known data, and max pressure would need to be found....wouldn't want to do that on an action with a .700" bolt. With the performance cases like this get, with a 100 yard zero.....it only takes around 12 MOA or less to reach 1000 yds at my elevation. That's just dumb ha ha
HARPERC
Well-Known Member
Sensible.
Truthfully I've been unaware of the 131 until you mentioned it. I thought you meant 137, but checked and there it was.
Perhaps if the 124's have issues, maybe a few more grains could be a better balance.
Thanks!
Truthfully I've been unaware of the 131 until you mentioned it. I thought you meant 137, but checked and there it was.
Perhaps if the 124's have issues, maybe a few more grains could be a better balance.
Thanks!
Y'all are killing me......... and my wallet
RockyMtnMT
Official LRH Sponsor
That is also in the plan. We have the reamer.
codyadams
Well-Known Member
Ha ha that's awesome. I assume the COW method for fireforming, or a designated forming barrel would probably be best. Is the reamer set up to turn the necks from a 300 Norma?
RockyMtnMT
Official LRH Sponsor
Yes.
We have been making a plug that will go into a break open 12g shotgun cut with the reamer for fireforming with the COW method.
codyadams
Well-Known Member
That is genius.
I have a design I did several years ago in Quickdesign using a 300 Norma case necked down to 6.5 with a 40° shoulder and a very long neck similar to a 6.5x47 Lapua and it calculated out to 105.6 grains of water.
I would actually be more interested in something like that than the RUM case design. One thing I'm curious of through, why the 338 Norma case over the 300 Norma? 338 Norma is quite a bit more expensive from what I've seen.
I've considered building the 6.5-300 Norma "improved" as a switch barrel setup with a 300 Norma improved barrel as well.
