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....)
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....)
