I ran down to the post office this morning and picked up a small package sent from Alberta Canada. Inside were a very limited number of very impressive looking aluminum tipped 338 bullets from my good friend Richard Graves.
Initial testing with this bullet design had not gone real well in my worn 1-10 Lilja barreled 338 Allen Magnum. The reason was the thin jackets used on those first bullets. Some barrels proved very accurate with these thin jacketed bullets. My 338 AM and 338 Kahn however ripped them apart on nearly every shot.
These new bullets were made with a much thicker jacket, similiar in thickness to Richards original ULD RBBT in 338 which shot extremely well in my Kahn and 338 AM.
There were two bullet weights. As these are just prototype bullets, the final weights may very slightly but these came in at 266 gr and 311 grains each. The 266 grain bullets were roughly 1.9" in length and the 311 gr are just over 2.250" in length!!!! For comparision, the 300 gr SMK will on average run around 1.720" in length!!!
I had a very limited number of each as Richard was just curious if they would hold together before building a big run of bullets.
After taking some baring surface measurments, I found the 266 gr bullets had slightly less baring surface then the 300 gr SMK. The max working load I have used with the 300 gr SMK in my personal rifle is 142.0 gr so I decided with the lighter weight bullet and slighly less baring surface, 145.0 gr should be alright. I only had three of these to shoot so I loaded them all up at this level.
I did not believe that my 1-10 twist barrel would keep the 311 gr pills on point with their extreme length but I did want to see if they would hold together out of the 338 AM so I loaded them up over some WC872 from 132.0 gr up to 138.0 gr just for velocity testing and to see if they held together.
I cleaned ol Black Sunshine and to the 100 yard range I headed. Again, we just wanted to see if they held together so that was the reason for the close range shooting.
I set up the chrono and to start things off I fired one round using a 300 gr SMK over 142.0 gr H-50BMG. THis gave a velocity of 3389 fps which is about typical of this load in this rifle. The shot landed where it should have.
I then shot the three 266 gr Al. Tipped RBBTs and will be honest, shooting on 14x on the NF NXS I could not tell if the bullet hole was opening up any. Had I not been able to see the dust kick up from behind the target backer and hear the solid hit from each shot, I would have thought they still came apart.
But every shot kicked up a large dust plumb and had a solid smack as bullets that stay on point do. I walked up to the target and once I got there I could see that they had all went into the same hole. Now we say that alot, bit this was no doubt, all went into the same hole.
When I got back to the shop I put the calipers to the group and found out this is my personal best 100 yard three shot group with any rifle measuring right at 0.058" for three shots.
Not only was the accuracy extreme, but the three shots tripped the chrono at 3544, 3547 and 3544 fps!!! Even better yet, there were no pressure signs at all. I would expect 3600 fps is fully practical with this bullet in the 338 AM with a long barrel.
My comfortable load with the 300 gr SMK is 3350 fps so bascially this new bullet design will allow a nearly 200 fps boost with an improved BC as well. I am predicting a BC of at least .850 from this bullet and probably higher then that.
Next up were the VERY long 311 gr pills. I knew they would not stay on point and they did not, BUT, the good news is that 5 of the 7 shots landed on paper and all held together including retaining their tips so in the proper twist barrel, these should prove easily up to any stresses the 338 AM can throw at them.
I only got them up to 3120 fps with VERY low pressures. I would not be suprise to easily brake 3200 fps and possibly even push 3300 fps. Even though these bullets do not weigh much more then the 300 gr SMK, they have a much longer baring surface so velocity potential will be less then the 300 gr SMK.
That said, the BC of these bullets in a properly twisted barrel should be totally unreal. I would predict .950 to .975 to be conservative and it would not suprise me at all to have to use a BC of 1.0 to get the the ballistic programs to match up with the actual bullet flight of these bullets.
This pic compares one of the 311 gr pills on the left to a 300 gr SMK on the right. Not much of a comparision!!! [img]/ubbthreads/images/graemlins/grin.gif[/img]
Add to all that the terminal performance of the very heavy jacket with the aluminum tips and basically you get all the benefits of a VLD solid bullet in BC with the accuracy of a SMK in the lead core design and the expansion characteristic at long range of a Ballistic Tip.
More testing to come but if they continue down the road they are heading on, the only way to discribe these bullets maybe the "wonder" bullet from up north!!!
More to come