6.5 Prometheus (6.5 PRO) 140 gr. 3700 fps

[Swamplord]

Gentlemen.....
I apologize for the delay and will post some relevant info to update the progress on this cartridge......


I necked down 60 pcs of 300 Norma Mag brass to just lightly close the bolt for head space and seated a bullet in a case to see if it will run....... but as I suspected the round would not chamber due to the neck thickness , the solution was to COW fire form the cases using 20 gr of Alliant Blue Dot pistol powder topped with COW to base of neck and a piece of toilet paper to hold the contents.. the cases came out nicely formed although slightly rounded shoulder but head space on shoulder was correctly set by process....

After fire forming I also discovered the donut inside the case neck ( neck /shoulder junction from 300 Norma Mag neck) did not get completely ironed out... had to order a case neck inside reamer
( that caused the delay in the project.... among a few other things)

cases were left in fire formed state and when the Forster neck reamer arrived I ran them all by reaming the excess material and the donut out inside the neck, then ran them through my FL die to set the ID of the case neck at .262" and when bullet was seated the OD was at .292" creating a neck clearance in chamber at .004", (chamber neck dimension is .296" ) still leaving the neck walls at a decent .015" thick.......



now this may seem like a big hassle and a lot of work but really it was very simple, fire form by COW method and run through inside neck reamer once and through FL die once and that was it.... the beauty of this is that it created a nice uniform neck thickness and a neck that was .347" long.... a much needed neck length for this powder hungry case !

**Note**
If accuracy is not satisfactory from inside neck reaming , on the next batch of brass I will run the COW fire formed cases through the full length die then a 6.5mm expander and outside neck turn to compare to inside neck reaming ...


The barrel used for testing these loads is a 26" 8.5 twist Brux in Rem Varmint contour, fluted with 11 degree crown & no muzzle brake.....
Magnetospeed chronograph
Temp. at 40 degrees F with clear skies, full sun and absolutely no wind, not that it matters I wasn't shooting for groups only velocity recording with incremental powder charges to establish known velocity for this untested wildcat.. and breaking in barrel at the same time..... no scope mounted.... since Magnetospeed chronograph has been shown to affect bullet groups and I was anxious to get some shooting done ......

I thoroughly cleaned the barrel after the COW process before shooting these loads....

I believe that most guys tend to be over zealous in their bore scrubbing .... I did no special barrel care to enhance the longevity of the throat, I treated it as any other rifle in my possession to have a record of normal usage for a round count until barrel needs to be set back... hence my break in consisted of ....

I started with min. load of 87 gr. fired 2 shots, let cool for 15 min fired 3 more and let cool 15 min and so on...
after the initial 2 shot string followed by six 3 shot strings, (20 shots total) I thoroughly cleaned the barrel and let it cool completely for 1 hour .... ( no other reason than that gave me some time to shoot some loads in my other wildcat the 375 PRO)

then I repeated the 3 shot & 15 min cooling for the remainder seven 3 shot strings (21 shots)
total of 41 shots fired.........


All loads consisted of.....
Powder, US869
Primers, Federal 215 Large Mag Rifle
Bullets, 160 gr Matrix VLD
bullet ogive contact with rifling length at 2.751" ( coal 3.400")
bullets were seated for a jump of .090" at ogive length of 2.661"
( following seating depth recommendation from several experienced LRH shooters from the 160 gr Matrix thread..... you guys know who you are ..thank you..)

I wanted a full velocity test with US869 and the 160 gr Matrix so I used the known starting loads for the 26 Nosler with 140 gr bullets as a starting point.......

these are the results.... all in order, as fired and recorded by the Magnetospeed Chronograph...

87.0 gr 3004 fps
87.0 gr 2985

88.0 gr 3134
88.0 gr 3109
88.0 gr 3080

89.0 gr 3086
89.0 gr 3082
89.0 gr 3101

90.0 gr 3111
90.0 gr 3095
90.0 gr 3150

90.5 gr 3136
90.5 gr 3134
90.5 gr 3101

91.0 gr 3142
91.0 gr 3142
91.0 gr 3128

91.5 gr 3174
91.5 gr 3150
91.5 gr 3154

92.0 gr 3227
92.0 gr 3168
92.0 gr 3192

92.5 gr 3219
92.5 gr 3184
92.5 gr 3188

93.0 gr 3280
93.0 gr 3253
93.0 gr 3215

93.5 gr 3253
93.5 gr 3289
93.5 gr 3272

94.0 gr 3322
94.0 gr 3320
94.0 gr 3333

94.5 gr 3320
94.5 gr 3306
94.5 gr 3317

95.0 gr 3380
95.0 gr 3357
95.0 gr 3337

no pressure signs of any kind were detected, no indications of pressure on brass, bolt lift was smooth and light, recoil was not noticeably different from the light to heavy loads...


I may be able to reach 3500 fps with the 160 gr Matrix ........ as it stands now, I can coat the bullet with WS2 Tungsten Disulfide (Danzac) and easily reach 3500 fps but will continue with uncoated bullets to establish a max velocity level for this bullet, powder combo....

will continue in .5 gr increments until pressure signs appear and will report here...

(as time and work allows....)

 

[Outlaw6.0]

Thanks for the update brother, i'm very interested to see where she leads you.

PS- that is one **** sexy looking cartridge.


t

 

[Swamplord]

I also wanted to clear the confusion on case capacity on this cartridge
I initially reported the case capacity of 105.0 gr h20 (104.6 gr) as estimated by the Quick Design software I used to develop this cartridge, my case capacity report was quickly challenged by another party and it was demanded that actual case h20 capacity as 102.9 gr as per their estimate...

It appears they are incorrect as I have just weighed 20 fireformed cases and 18 times came up with 105.0 gr of water, the other two weights were 105.1 and 105.2.....

 

[264WM]

This is looking good and I have already talked to my gun smith about the 6.5 pro. He says it should be no problem for the Enfield 3006 rifle to be converted. Just a little machining on the bolt face (less than $100) and a new barrel.

 

[Swamplord]

This time around I loaded up 15 cow fire formed cases ( see brass prep on post #57 at top of this page) with 160 gr Woodleigh Weldcore PP SN bullets that I coated with WS2 Tunsgsten Disulfide...

Max COAL in my chamber is at 3.399" and max ogive oal is 2.808" ( contact with rifling )

COAL in these loads is at 3.347" and Ogive oal is 2.764" ( .044" bullet jump )

I did not have a scope mounted for accuracy testing... this was a test with bullet and powder combo to establish a known velocity range and max powder charge........ and I was busy doing an accuracy test with my other wildcat the 375 PRO.....

http://www.longrangehunting.com/forums/f19/375-norma-127219/index7.html

US869 powder.....

95.0 gr 3378 fps
95.0 gr 3353
95.o gr 3344

95.5 gr 3378
95.5 gr 3373

96.0 gr 3373
96.0 gr 3401

96.5 gr 3434
96.5 gr 3448

97.0 gr 3429
97.0 gr 3460

97.5 gr 3484
97.5 gr 3481

98.0 gr 3484
98.0 gr 3491

Just when I was beginning to think that I won't reach max pressure with these loads, I got into it with the 97.5 gr load....... got a slight difference in bolt lift, just a bit tighter than before...

then with the 98.0 gr load, bolt lift was obviously heavier than the previous load... I could probably load up to 100 gr ( have room in the case..) before reaching clear and obvious pressure signs on the cases, but with these sturdy Lapua cases even a faint pressure sign is a clear indication that it is time to stop !!!!

I am calling max safe load for my rifle/barrel with the **WS2 COATED** 160 gr Woodleighs at 97.0 gr of US869 with
3444 fps (2 round ave. at this point)

that is not too shabby with a 26" barrel... once all load development is done I will have my 30" 8 twist 5R Bartlein barrel installed and will easily exceed 3500 fps with 160 gr bullets and will reach my prediction of 3700 fps with 140 gr bullets..................

**WARNING** this load data is not to be used with uncoated bullets, It was developed with Danzac WS2 powdered Tungsten Disulfide , applied to bullets by tumbling with ceramic kernels and WS2 powder in a vibrating case tumbler for 45 minutes.........


........

 

[264WM]

That would be numbers I like as so far I have only reached 3095 fps with the Woodleigh 160gr ppsn with my 264wm. Have you obtained any JLK 130gr VLD's yet? They should be closing in on 4000fps which would make them a super load.

 

[Iron Worker]

Now those are some 21st century velocities , can't help but wonder about bbl life.

 

[Swamplord]

Now those are some 21st century velocities , can't help but wonder about bbl life.

It's pretty obvious you have not read this thread and are here to troll !
otherwise you would have read this part ( post #21 page 3 of this thread) that applies directly to you

"This cartridge was designed with the knowledge that barrel life will be limited, if one is inclined to dwell on barrel life, go bald worrying about it or become afflicted with bedwetting from bad dreams induced by the terror of less than 2k rounds of barrel life ... well , these little girls need not play with evil barrel consuming monster cartridges ... ( whew ! had to let that out, feel better now!) "


.....

 

[Iron Worker]

It's pretty obvious you have not read this thread and are here to troll !
otherwise you would have read this part ( post #21 page 3 of this thread) that applies directly to you

"This cartridge was designed with the knowledge that barrel life will be limited, if one is inclined to dwell on barrel life, go bald worrying about it or become afflicted with bedwetting from bad dreams induced by the terror of less than 2k rounds of barrel life ... well , these little girls need not play with evil barrel consuming monster cartridges ... ( whew ! had to let that out, feel better now!) "


.....

Personal insult is always the first recourse of an empty mind .

 

[264WM]

I think swamplord is just tired of hearing the barrel life thing over and over in this thread and would like people just to read the thread and they will understand that barrel life does not have any weight in the development of this round. Had people continually proclaimed the dangers of a explosion to the inventor of nitro we may not have it. ;-)

 

[Swamplord]

Personal insult is always the first recourse of an empty mind .

If you truly believe that then don't insult others !

The only reason you post on this thread is to incite a riot, this is the extent of your contribution here .....

"Hey what kind of BBL life I mean less than 500 ?"

"The 26 Nosler is over bore,but this caliber lives in Twilight zone."

"Ok I should of said cartridge ! 260 Remington and yours are same caliber . Geez some people !"

"Now those are some 21st century velocities , can't help but wonder about bbl life."

"Personal insult is always the first recourse of an empty mind ."

You obviously have no interest in this cartridge so why bother with your idiotic comments ? The issue of barrel life was brought up and I addressed it and explained that it is NOT a detriment in this project but in fact it was my intent to burn a barrel with initial load development in order to document actual round count before barrel needs to be set back !


Does this cartridge and it's development offend you so much that it causes you personal stress ? If it indeed is affecting your life and you are losing sleep and are developing an ulcer worrying about someone else burning a $350 barrel, I can ask Len to delete this entire thread and I will not post anymore harmful information and data obtained with this cartridge !

 

[264WM]

I personally like reading about this new 6.5 and hope you keep posting updates. Once you have finished all the testing I am talking with my gun smith on building one. If you decide to end this thread please keep me posted on my private messages.

 

[Iron Worker]

Out of respect for others I'm with drawing from this....... Hey Dude did I call you names? I just made a observation of high velocities and which led to a logical question. I work and don't have time to read every single post on any particular thread .When some one says something you don't like are you obligated to take it personally ?

 

[264WM]

Swamplord here is some food for thought as this is a AR style rifle in 338 Norma mag which would make a perfect choice to re barrel to 6.5 pro as the action is already set up right. What do you think?