I got a 0.170" center-to-center 3-shot group with the first 3 I fired at 100 yards.
The 510 JAB (500 A2 variant) has never shot so well. Velocity was 2126 fps with 110 grains of IMR-4350, F-215 primer, Weatherby brass (Norma). This is a low pressure and accurate load.
Velocities of the ~700 grain milsurp AP and ball were about the same, but their accuracy was dismal by comparison to the AAA bullet.
Sorry I waited so long to try those bullets, but BMG knew they were good, I am sure.
Now I will be looking to stock up on those great bullets.
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RAB
The COL for this load was 4.632". This is the 705 grain "Harlow" match solid,moly, right?
The rifle was the 27" barrel Ruger No. 1 with a 1.000" muzzle diameter, 1 in 10" twist, stainless McGowen. The throat is the 0.588". I have no concentricity problems with the re-throated 500 A-Square, I reckon.
My Brno ZKK 602 has a 23" 10 twist, 0.875" muzzle diameter (straight taper), stainless McGowen barrel and the throat is a 0.300" freebore plus ? leade (Dave Manson custom reamer, 510 JAB). The 4.632" COL load works well in that chamber, bolt closes effortlessly. I have no runout problems with my ammo, I guess. Used the Ammo Master press.
I expect the 23" barrel will produce velocities around 2050 fps with this load, but this load is a secondary one for that gun, which mainly is intended for the 570 grain hunting bullets. The 4.632" long cartridges can be loaded through the action port by laying the cartridge on the follower with the bullet tip started into the chamber, pushing down the base of the case into the magazine and pushing the bolt forward to start CRF-ing the round the rest of the way, and ejecting the empty case or reversing the process to get the unfired cartridge out ... or remove and replace the bolt, shellholder style.
These 705 grainers are more pleasant and accurate in my plinkers than the 750 grain Hornady A-max bullets were.
I am sold. Thanks.
http://www.aaa-ammo.com/index.htm
Right? ... kind of odd music with website, minor key, spooky, but click on the "Dedication to Our Fellow Americans" for something better.
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RAB
[This message has been edited by DaggaRon (edited 04-21-2002).]
The AP bullets averaged 693 grains +/- about 15 grains.
The ball averaged 668 grains and I don't remember their spread in weight.
The velocities on the AP and ball were within the 2100 to 2200 fps bracket: all over the place. Ball slightly faster than the AP. Not worth analyzing.
Five shots of the "Harlow" bullet averaged 2126 fps with an extreme spread of 9 fps. No Sd calculated on this small sample.
Conclusion: Not surprising. The 705 grain AAA Ammo bullet wins, but in a very convincing way. The milsurps are just for plinking.
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RAB
[This message has been edited by DaggaRon (edited 04-21-2002).]
Just so Ray doesn't think me negligent, let me say that anyone wanting to try this should drop back to 100 grains and work up with the IMR 4350. When I first started off with IMR 4350 and the 750 grain bullets, I started at 96 grains and worked up one grain at a time.
Also note that 110 grains of IMR 4350 pushed the 750 grain Hornady A-Max along at 2150 fps (an exact average of five shots), with COL of 4.756" in the Ruger No. 1. This would group 3 shots into 0.960" on centers at 100 yards.
105 grains of IMR 4350 gave the 750 A-Max a velocity of 2057 fps (average for 5 shots) and a 3-shot group of 0.703" on centers for my best with the A-Max. I just went back and looked at my logbook.
The "Harlow" is a lighter bullet delivering slightly lower velocity, so I am pretty darn sure it is a very safe load. I was using the non-moly-coated A-Max, but the "Harlow" is moly coated. Also the "Harlow" is a semi-bore-rider, while the A-Max has a full bearing surface shank.
I am sure the "Harlow" could move faster safely with a higher charge, but I have not gone there, and see no reason to, since it is so accurate in my rifle at the sedate and low pressure 2126 fps. Fun to shoot.
BTW, BMG, do you have a ballistic coefficient for that needle-nosed bullet?
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RAB
[This message has been edited by DaggaRon (edited 04-22-2002).]
Do you think that bullet would expand on a large game animal like a moose or elk?
Another part I like about them besides the ones you stated (extremely accurate, less bearing surface, HIGH BC, low pressure) is that the bullets are 'self aligning' in the bore. The front driving band is .500" which centers itself on the top of the lands while the rear driving band is .510" which creates the gas seal in the grooves. Also, the bullet is a monolithic solid so there isn't ever an issue of a 'lopsided' bullet which happens with any non-solid bullet (and especially with mil-surplus which can be made from up to 9 different components within the copper jacket).
The Harlows are 'good people' and have excellent products.
Boiled down data from above is:
0.170" 3 shot group (first 3 shots), 2126fps avg, 705gr AAA Semi-boreriders, 9 fps spread out of 5 shots
0.703" 3 shot (best ever 3 shot group), 2150fps avg, 750gr A-Max
Sooo...
The 705gr AAA bullets shrank your best sub-MOA group by over half an inch, were more 'pleasant' to shoot, had less than 10 fps variation out of 5 shots, and develop less pressure for longer brass & barrel life.
I plan on shooting mil-surplus from all my .510" firearms because of the cheap plinking price and 'acceptable' (if you want to call it that) accuracy. However, when I want serious accuracy or am 'challenged' to an accuracy contest (scored match or informal gentlemans bet), I'll definately top off the brass with a 705gr AAA Semi-borerider. They're simply the best.
It's a shame it only took you 10 months to try them out ;-) I'm glad you liked them.
500grains,
It is not a 'hunting' bullet. It is pointy and turned from a solid bar of copper based alloy on a CNC machine and meant for extreme accuracy. It would pencil right through any 'soft' material it hit.
AAA Ammo now makes a 720gr hollow point, although I havent seen it, and this might work well on game animals. I'll have some in less than 1.5 months to 'test'. I'll let you know.
And then there are the gunsmiths that take forever to finish a custom rifle order! That's life.
I wasn't aware of the "alignment" trick with the .500" and .510" diameter bands. Do any of the other bullet makers do this? Must be a good thing.
Thanks again for introducing me to these bullets. Do you have a ballistic coefficient for these jewells so that I can get a paper trajectory for a try at 1000 yards?
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RAB
BMG,
I didn't mention that I also attended the Mitch Institute of Trigger (M.I.T.) in long Island, New York over three different weekends for recoil desensitization with a 577 Tyrranosaur. This might have helped with the group shrinkage too, but I am sure the new bullets were the major factor.
Please let me know if you have a ballistic coefficient. Must be pretty close to 1.000, eh?
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RAB
I will be using these in an FCSA match in early June and will 'tip a pint' with the makers of these moly coated wonders. Have a good one,
BMG
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RAB
The Harlows were out of stock for a while, but as of this week they have plenty to go around.
Don't worry about sending me some back as repayment, but thanks anyway. I sent them as a 'Thank You' for your helpful info & reamer use for my own .510/460 Long (that is waiting for a McMillin stock). I'm just glad they worked well for you. Thanks anyway though, I appreciate the jesture.
BMG
ps. The 50BMD (.510/460 Short) will stay supersonic beyond 1000yds with the 705 grainer :-)
Dang this bullet is fun.