Post by bluedot on Nov 21, 2020 22:12:12 GMT -5
Long story short, I needed to work up a new load for the rifle using the Berger 195g EOL bullets.
I had worked up a load for the range when Picklehead was here 2 years ago, but when we were there I found out I neglected to check to see if they'd fit in the magazine. They wouldn't.... So, in order to use it for hunting I might as well take advantage of having the magazine and use the dang thing! Then we shot 1 shot over the chronograph from a clean cold barrel and it was 3068 fps. When we got to the range the drop chart was way off, it was shooting low by 2 moa. I knew that after the 1st shot was low so I corrected it back them.
So, since the weather was nice temp wise (I don't want to talk about the wind) I decided to play a bit.
I corresponded with the 'smith that build the rifle (Kirby Allen, Allen Precision Shooting) about switching powder when I was having problems with temp sensitivity with the WC-872 powder. That was THE powder to use in this chambering to get full value of the case capacity to shove very heavy for caliber bullets fast. While I don't have the barrel length that some have, and not the exact twist for the 200g Wildcat bullets that were available when the rifle was built, the supply of those bullets has disappeared and I started with 175g Sierra Matchkings, then switched to 180g Berger VLD's when the 175g SMK's were blowing up in mid air at 50 yds. Now that Berger is producing the 195g VLD EOL bullet, I wanted to develop a load for that one.
Kirby said that I should try RL-33 as it was temp stable. I asked him about RL-50 and he said that the burn rate was good, but they had issues of it bridging because of the large kernel size and he didn't recommend it, and he had no load data for it, just a recommended starting point. He recommended that I start with 92g of RL-33 and go up from there, keeping an eye on fps and any signs of pressure.
I was running the 180g Berger Hunting VLD's @ 3350 fps with the WC-872, and prior to that I was running the 175g SMK's @ 3475 fps with the same powder, using Fed 215Mag Match primers. Kirby suggested not to use the Match primers for the RL-33.
So I did the test like he recommends. Pick a starting charge, increase the powder charge by approximately 1% and watch fps. Stop when there are signs of excessive pressure or you see the incremental fps increase for every 1% increase in powder charge slow down.
I only shoot a max of 3 shots through the gun, then let the barrel cool. Chronograph set 20' from the muzzle.
Temp 65°F
Baro 29.20
RH 40.3
Elevation corrected for atmospheric conditions 670' (actual elevation is 890')
Here's the data:
Charge FPS
92g 3061 (Clean cold barrel. This is why my first shot from a clean cold barrel always hits 2 MOA higher than the subsequent shots)
92g 2945 (Fouled barrel)
93g 2963
94g 2987
95g 3059
96g 3084 (This is the sweet spot that Picklehead and I settled on to shoot at the 1K range 2 years ago)
97g 3099
98g 3112
BUT, this isn't the speed that the 200g Wildcat bullets were getting with the WC-872 powder so I decided to try the RL-50 Powder.
Now the usual disclaimers have to go with this. Do NOT try this in your gun, blah, blah, blah. It might blow up and I won't take any responsibility for it.
So did a load development test with the 7mm Allen Magnum using RL-50 powder. There is absolutely NO load data on this powder with this cartridge. Just to verify velocity. I started at 97 grains and increased the charge 1 grain at a time until I saw the velocity top out or more exactly NOT increase 30-50 fps with every 1.0 grain increase in powder. Also looked at the case base to see if there were any traces of "wiping" i.e. marks that the bolt left on the face as it rotated.
As the gunsmith (Kirby Allen) told me about doing tests like this, he said at low powder charges the fps is erratic, one might be fast, the next increase might be slower etc. Not until you start hitting the sweet spot does the fps incrementally increase. HE also said he didn't like using this powder because he had seen powder bridging issues in the powder drop tube due to the large kernel size and recommended NOT using this powder for that reason. I was using WC-872 and getting great groups and great velocity with the 180g bullets, but found out that it is a very temp sensitive powder, and to keep the velocity approximately the same, for every 10°F drop in temp I had to increase the powder charge. Pretty impractical to do that for a hunting gun. So, I was searching for a more temp stable powder. He (Kirby Allen) said to use RL-33. I did and it did just fine with the 180g bullets (see the fps above), but when I jumped to the 195g EOL Bullets, I saw signs of high pressure before I got to the velocity level that I was expecting (burn rate too fast). So, I decided to try the RL-50.
These were all cases that I had loaded previously, and I pulled the bullets, only sizing the necks using a neck sizing bushing die. (I found out that by using the neck only sizing die the cases showed higher signs of pressure than if I did a FL resize of the cases and bumped the shoulder back 0.0005" when I was doing another powder test a year ago.)
I'd shoot 3 shots, then let the gun cool back down.
Here's the data
Charge FPS
97g 3041
98g 3041
99g 3072
100g 3116
101g 3164
102g 3222 Tight neck when seating bullet
103g 3250 Tight neck when seating bullet
104g 3271 Tight neck when seating bullet Slight wipe from bolt
105g 3270 Slightly more of a wipe mark from the bolt, no mark from the ejector, stopped test
So, I loaded 5 rounds at 102.5g and shot them at the 300 yd target. First shot was 14.25" high and 2" right.... Dumb nut behind the trigger looked at the bullet drop from the 100 yd zero and adjusted the scope the correct amount of MOA up, but forgot to take into consideration that I was now shooting at 300 yds and not 100..... So, for the last 4 shots I clicked it back down the appropriate amount. I let the gun cool down.
I also adjusted .75 MOA left. I didnt' know if the wind was screwing with me or if the zero was off. I then used Kentucky windage to hold into the wind instead of using the dial, because the goal was to use the gun for hunting the next day when the wind was completely different. 2nd shot was 1/4" low on vertical, but 1" left. I adjusted scope .25 moa right. Wind was variable, 10-20 with gusts to 30 mph, about 1/2 value from right to left, but the last 200 yds was in the woods. 3rd shot was 1/2" right of center, dead on the vertical.
Let gun cool
4th shot chambered a wee bit tight, case wasn't quite sized to what the others were and the FPS and the POI showed. That one went 1.5" right and 1.5" high. 5th shot went thru the hole that #2 or #3 made. No way did I completely miss the 2' x 4' piece of cardboard, no way. It looks like hole #2 is a wee bit larger than .284".
Velocity was as follows:
#1 3225 (14.25" high and 2" right)
#2 3220
#3 3219
Let gun cool
#4 3277 (chambered a wee bit tight)
#5 3222
So did a load development test with the 7mm Allen Magnum using RL-50 powder. There is absolutely NO load data on this powder with this cartridge. Just to verify velocity. I started at 97 grains and increased the charge 1 grain at a time until I saw the velocity top out or more exactly NOT increase 30-50 fps with every 1.0 grain increase in powder. Also looked at the case base to see if there were any traces of "wiping" i.e. marks that the bolt left on the face as it rotated.
As the gunsmith (Kirby Allen) told me about doing tests like this, he said at low powder charges the fps is erratic, one might be fast, the next increase might be slower etc. Not until you start hitting the sweet spot does the fps incrementally increase. HE also said he didn't like using this powder because he had seen powder bridging issues in the powder drop tube due to the large kernel size and recommended NOT using this powder for that reason. I was using WC-872 and getting great groups and great velocity with the 180g bullets, but found out that it is a very temp sensitive powder, and to keep the velocity approximately the same, for every 10°F drop in temp I had to increase the powder charge. Pretty impractical to do that for a hunting gun. So, I was searching for a more temp stable powder. He (Kirby Allen) said to use RL-33. I did and it did just fine with the 180g bullets (see the fps above), but when I jumped to the 195g EOL Bullets, I saw signs of high pressure before I got to the velocity level that I was expecting (burn rate too fast). So, I decided to try the RL-50.
These were all cases that I had loaded previously, and I pulled the bullets, only sizing the necks using a neck sizing bushing die. (I found out that by using the neck only sizing die the cases showed higher signs of pressure than if I did a FL resize of the cases and bumped the shoulder back 0.0005" when I was doing another powder test a year ago.)
I'd shoot 3 shots, then let the gun cool back down.
Here's the data
Charge FPS
97g 3041
98g 3041
99g 3072
100g 3116
101g 3164
102g 3222 Tight neck when seating bullet
103g 3250 Tight neck when seating bullet
104g 3271 Tight neck when seating bullet Slight wipe from bolt
105g 3270 Slightly more of a wipe mark from the bolt, no mark from the ejector, stopped test
So, I loaded 5 rounds at 102.5g and shot them at the 300 yd target. First shot was 14.25" high and 2" right.... Dumb nut behind the trigger looked at the bullet drop from the 100 yd zero and adjusted the scope the correct amount of MOA up, but forgot to take into consideration that I was now shooting at 300 yds and not 100..... So, for the last 4 shots I clicked it back down the appropriate amount. I let the gun cool down.
I also adjusted .75 MOA left. I didnt' know if the wind was screwing with me or if the zero was off. I then used Kentucky windage to hold into the wind instead of using the dial, because the goal was to use the gun for hunting the next day when the wind was completely different. 2nd shot was 1/4" low on vertical, but 1" left. I adjusted scope .25 moa right. Wind was variable, 10-20 with gusts to 30 mph, about 1/2 value from right to left, but the last 200 yds was in the woods. 3rd shot was 1/2" right of center, dead on the vertical.
Let gun cool
4th shot chambered a wee bit tight, case wasn't quite sized to what the others were and the FPS and the POI showed. That one went 1.5" right and 1.5" high. 5th shot went thru the hole that #2 or #3 made. No way did I completely miss the 2' x 4' piece of cardboard, no way. It looks like hole #2 is a wee bit larger than .284".
Velocity was as follows:
#1 3225 (14.25" high and 2" right)
#2 3220
#3 3219
Let gun cool
#4 3277 (chambered a wee bit tight)
#5 3222
So, I'd say that the load shows some promise!!