200 grain 6.5 revisited (Attention Elkaholic, and Hammer)

[TXAoudadKlr]

What bullet is going to be run out of this monstrosity?

 

[Deviant]

Tag this sounds like too much fun to miss out on.

 

[HARPERC]

Steve has a 165 Hammer Hunter to start with. See what happens with that to begin with.

 

[Just cut]

Tag

 

[RockyMtnMT]

We designed a Hammer Hunter that is pretty close to 2" long and came in at 165g. It is much more proportional than I thought it was going to be. We will see when we light a fire under it, but it looks to me like it will have no trouble with the launch speed. I was worried about it wringing or slipping in the rifling. After making the bullet, I don't think it will be a problem.

Ramshot LRT is the top of the list for powder. The little bit of testing that we did with it last week showed it to be a fare bit slower than the rl33. Being a ball powder is essential to consistent ignition on this major overbore. When we worked with this cartridge a few years ago the only powder that came close to working was US869. It was way too volatile with temp changes though and had to be loaded down quite a bit to not lock up with small temp changes.

Looking forward to shooting this one.

 

[TXAoudadKlr]

A gain twist sounds like it be appropriate for a project like this but will limit you to just solids

 

[Pdvdh]

Ramshot LRT is the top of the list for powder. The little bit of testing that we did with it last week showed it to be a fare bit slower than the rl33. Being a ball powder is essential to consistent ignition on this major overbore. When we worked with this cartridge a few years ago the only powder that came close to working was US869. It was way too volatile with temp changes though and had to be loaded down quite a bit to not lock up with small temp changes.

Looking forward to shooting this one.

Is RL33 a no-go due to powder bridging and pressure spikes?
Kirby just started a thread on his new 6.5 wildcat cartridge (26 Stalker) based on the shorter 300 Norma Magnum parent case. I was a little surprised to see he's been able to use RL33 in his 6.5, evidently with good performance and no pressure spikes/issues so far.

 

[TXAoudadKlr]

Wonder if RL50 would be better?

 

[HARPERC]

.......A gain twist sounds like it be appropriate for a project like this but will limit you to just solids.......

We considered the gain twist, and ultimately decided it added another variable that's been difficult to nail down an advantage for. Certainly being used by some that feel it's an advantage, but also those not seeing it. One of those variables in the game tough to isolate from the many variables involved.

That said there may be gain twist some where in my future just to satisfy curiosity.

I don't see mono, solids, turned or however we refer to them as a limit, but rather the next step in bullets. The precision machinery to turn out consistently better products is impressive. Additionally, the ability to experiment with new bullets, or turn out a wild hair project for an individual, can't be matched by other processes.

Chasing what the limits may be in such a bullet is at the heart of this particular build.

 

[TG-5150]

Tagged in too

 

[Swamplord]

I've neen using RL50, RL33 and N570 with 150 gr SMK's and 165 gr Chinchaga ULD HP bullets with no problems in my 6.5 Skuldryl, have yet to see any powder bridging (is it even a real thing ?) or delayed ignition and I've shot it the dead of winter (Dec. 2017) in sub zero temps -12 F and up to 75 F in the summer, I'm thinking the shorter neck eliminates the powder bridging issue from occuring as I haven't seen the sudden pressure spikes with US869 in my 6.5 Skuldryl vs the long necked 6.5 Prometheus , hoping my local supplier will get me a couple cans of LRT here soon

used up the last of my Norma brass and have been using Petersen brass with awesome results, no loose pockets yet, have 50 pcs of 300 Norma Lapua made brass fireformed and will be torching the 8 tw Bartlein barrel and have a 7 tw Rock Creek ready

will the 7tw barrel work for the 165 gr Hammer Hunter ?

 

[HARPERC]

I'll let Steve answer that, but the barrel we're using is a 1-6" Bartlein.

 

[TXAoudadKlr]

We considered the gain twist, and ultimately decided it added another variable that's been difficult to nail down an advantage for. Certainly being used by some that feel it's an advantage, but also those not seeing it. One of those variables in the game tough to isolate from the many variables involved.

That said there may be gain twist some where in my future just to satisfy curiosity.

I don't see mono, solids, turned or however we refer to them as a limit, but rather the next step in bullets. The precision machinery to turn out consistently better products is impressive. Additionally, the ability to experiment with new bullets, or turn out a wild hair project for an individual, can't be matched by other processes.

Chasing what the limits may be in such a bullet is at the heart of this particular build.

Yeah, it another one of those unknown factors that's near impossible to tell if it's a plus or minus. I want to try one myself but as reasons you mentioned I've held off. Maybe when I shoot out my Gap-10's barrel I'll swap for a mild gain twist like a 1:8.5-1:7.5. I was told if you still want to shoot lead core not to go any faster than a 1" gain by Bartlien

 

[RockyMtnMT]

Is RL33 a no-go due to powder bridging and pressure spikes?
Kirby just started a thread on his new 6.5 wildcat cartridge (26 Stalker) based on the shorter 300 Norma Magnum parent case. I was a little surprised to see he's been able to use RL33 in his 6.5, evidently with good performance and no pressure spikes/issues so far.

Several years ago when we first tried the 6.5 Ultracat we saw some huge pressure spikes when trying different powders. The only powders that we seemed to get much consistency with were ball powders. Powder bridging... I'm not sure, but this time around we will start with the LRT ball powder. Also now that we are making bullets we are able to run a much bigger bullet than we had available then. 40g bigger. Right now the test bullet is 1.835" and is weighing in at 169.8g. This is showing a 1.61sg at 3000fps and sea level with a 6" twist. @Swamplord the 1-7" twist shows a 1.18sg at 3000fps. 3500fps only bumps it to 1.24sg. So unfortunately the 1-7" will probably have trouble with this one.