280 Ackley Imp with a Tuner

jackie schmidt

jackie schmidt

New member
I helped my good friend Ed Bernabeo put together a 280 Ackly Imp to make use of the out of the box Nosler Brass. Dave Kiff ground the reamer for this brass, minimum spec. The Rifle is based on a Rem 700 long action, a fully bedded Hogue stock with a 6-20 Leupold on top.

We left the barrel as long as the blank would give us, 28 1/4 inches. It is a Krieger 1-9 twist. The whole idea is to shoot the highest BC bullet in 7mm, right now the Berger 168 VLD Hunting Bullet and the 162 Hornady A-Max are what we are using.

The primary purpose, aside from just having a accurate high BC 7mm, is 500 yard Elk Rifle.

With reloader 22 and reloader 25, we can easilly hit 2950 with good accuracy, 3000+ is no problem but accuracy falls off quite a bit.

I have shot some 5 shot groups at 100 that will go .400, usually it is good for 1/2 inch or a tad above.

What we did this week was mount a tuner. I took the barrel off, threaded it to .800 32 tpi, and made a aluminum tuner much like what I use on my Benchrest Rifles with great success, a one piece unit that clamps directly to the barrel. The tuner is 2 1/2 inches long weighs 6 ounces with about 3/4 inches of overhang

I hope to get to the range this week end and see if I can tune this long tube with a tuner. It would be great to find a load at exactly 3000 fps, with a great ES and SD, and tune it into about .400 with the tuner.

Suggestions are welcome.

We will see what happens.........jackie
 
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Well I just need to open my big mouth.

My go to rifle for many years has been a custom built 280 Imp.

I have taken mule deer out to 424 years with it.

I have take many antelope and mule deer with this fine cartridge.

HOWEVER the 280 Imp is NOT a 500 yard elk rifle...................................

Sorry:)=
 
Jackie, we have been able to tune our 30" barrels with a couple of brass rings weighing about one ounce each. This rifle wears a 30" 7mm barrel set up to shoot the 180 Bergers about 2950 fps. The crown is just recessed a bit thus placing the rings behind the muzzle. Sam has also counter bored the crown back behind the rings like the second picture. Both ways work well. For good accuracy, you might also try some of the JLK bullets.

joe
 

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I've tuned 1200 yard guns with a couple of ounces behind the muzzle (excuse the fuzz - somewhere I have a better shot).

barrel.jpg
 
John S

I will be the first to admit that I am not a hunter. My contribution ends with installing the barrel, and helping out with the tuning. It's Ed's Rifle.

The more I think about it though, a 162 grn bullet at 2950 doesn't sound real "elkish" at 500.
 
Jackie,

Yes, I understand. I just had to comment.

Once again the .280 Imp is a very fine cartridge.

Once I go over a 140 grain bullet, I much prefer the 7 Mag.

BTW the Barns TSX is very accurate and deadly.

For bulls I like the .338 WM; however last year near Raton I harvested a nice cow with a .308, using a 165 Sierra SBT. Hearth shot at 200 yards and a clean pass through.

I could tell you about the big bull I shot at 325 yard with the .338 WM and a 225 PT. It was a perfect shot right behind the shoulder and I heard it smack hard. The bull ran about 200 yards and dropped dead. The bullet hit as stated made a right hand turn traveled some distance and made a left hand turn and exited the third rib from the back on the off side. Bulls can be very tuff.

Best wishes, Merry Christmas, Happy New Year and may 2011 be as great as 2010 was for me!
 
Jackie
The 280 AI will have right at 1890 foot/pounds of energy at 500 yards and the 338 with the 225's will have around 1830 foot/pounds of energy so I don't see any real big differences in power between the two.
On the tuner I would build it as a non-twistable unit
Waterboy as well so it doesn't get bumped or untuned when walking through thick brush.I would build it heavy and cut it down until best accuracy is achieved.
Waterboy
 
Jarrett says:

Jarrett says 2975 fps with the 160 grainers using these powder charges:

RL-19 @ 59 gr
RL-22 @ 58.5 gr
IMR-4350 @ 55 gr

I have never been able to reach Jarretts claimed velocities. My barrel is a 24" Krieger.
 
I have a 280 AI with a #5 contour 27" Shilen 1-8" twist. I tested some hunting loads with 168gr Hunting VLDs jammed .010" using H4831sc, n165, and Magpro. All 3 powders shot well. H4831 and n165 peaked out at 2980 fps, Magpro easily got 3075 fps!!! But it was pretty dirty. Settled with the n165 because of cleanliness and the 2980fps matched my Nikon Monarch BDC perfectly out to 500yds. Killed deer at 569 and 160 yards this year, both were BANG-FLOP.

Next year I may try the 180gr Hunting VLDs because of the higher BC. If I can't get about 2960fps out of it I may push shoulder forward like the Gibbs has.
 
Not That Good of a Day.

I got to the range early, got my flags and Ohler 35 set up. Started with enough reloader 22 to push the Berger 168 to an average 2975. Shooting 3 shot groups, never could get a tuner setting that would show less than .600.(100yards).

Started going up a little, found a setting that put 3 inside of .400, but flipped a shot to .800, then put the 5th shot back into the first 3.

Went to the .162 A-Max, no better, or worse than the Berger 168.

I then switched to some Reloader-25, great velocity out of the 28 inch barrel, but could shoot no better thatn .700 at 100.

I tried different seating depths, ended up firing about 80 rounds, (my shoulder flat hurts), and it seems this combo is locked into nothing better than .600 at best.

I am a little dissappointed. I really believe that I should be able to take a customed barreled Rem700 and get sub .500 accuracy on a fairly consistant basis. Or at least the Benchrest Shooter in me thinks I should. I know .600 to.700 is fine for a Hunting Rifle, but looking at those groups through the scope is not encouraging. Maybe these particular bullets just are not up to the task, maybe our choice to leave the barrel at a full 28 inches was off.

Heck, it ain't even my Rifle, and I feel really bad. Velocity is easy to come by, 3000 fps shows no pressure signs at all, the 28 inch tube must be working. Maybe a different powder bullet combo will work better in the ultimate accuracy department. I was working with what Ed had..........
 
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Jackie
The vld's from Verger like a huge amount of jump.My father is using 0.120 and some of the guys at our club are jumping them 0.185 off the lands.
I know you just fell out of your chair but no those are not typographical errors.If you go to bergers website you can see there seating depth article and it really does work.
One other thing I have always found when working up hunting loads is alot of rifles shoot better with a faster burn rate powder.Alot of guys go strictly after velocity but in my humble opinion a faster burning powder will generaly get you better accuracy.
Now back to your tuner since you didn't mention it.I find that the 6 ounce tuners seem very lazy on the long barrels we normaly use at 600/1000 yards.If you go to 11 ounces the tune seems to respond very quickly and predictably while the 6 ounce tuners don't seem to do as much.
Waterboy
 
jackie schmidt said:
Not That Good of a Day.

I got to the range early, got my flags and Ohler 35 set up. Started with enough reloader 22 to push the Berger 168 to an average 2975. Shooting 3 shot groups, never could get a tuner setting that would show less than .600.(100yards).

Started going up a little, found a setting that put 3 inside of .400, but flipped a shot to .800, then put the 5th shot back into the first 3.

Went to the .162 A-Max, no better, or worse than the Berger 168.

I then switched to some Reloader-25, great velocity out of the 28 inch barrel, but could shoot no better thatn .700 at 100.

I tried different seating depths, ended up firing about 80 rounds, (my shoulder flat hurts), and it seems this combo is locked into nothing better than .600 at best.

I am a little dissappointed. I really believe that I should be able to take a customed barreled Rem700 and get sub .500 accuracy on a fairly consistant basis. Or at least the Benchrest Shooter in me thinks I should. I know .600 to.700 is fine for a Hunting Rifle, but looking at those groups through the scope is not encouraging. Maybe these particular bullets just are not up to the task, maybe our choice to leave the barrel at a full 28 inches was off.

Heck, it ain't even my Rifle, and I feel really bad. Velocity is easy to come by, 3000 fps shows no pressure signs at all, the 28 inch tube must be working. Maybe a different powder bullet combo will work better in the ultimate accuracy department. I was working with what Ed had..........
Click to expand...

Mine loves 168vld's jammed about .010" and n560 at 2950fps, in a hunting rifle. --Mike
 
The best results were just touching, maybe a little in. I tried going at least .030 jump, deveoped about 1'' of vertical, figured that was not the way. Maybe I should have went way more, just not enough time.

I have a feeling that these particular bullets are simply not up to the task. Several times, I would have three darned near touching, and the other two would have a mind of their own, no particular pattern as to which way the flyers would go.

I need to ask Ed if he is sure about this scope. It is a fairly old 6 1/2 to 20 Leupold. Heck, I might be throwing bullets downrange under a bad scope.
 
Ahhh...load development on an Ackly Improved...

Yep..you took on a monumental task...you just aren't at the halfway point of frustration "YET"...get a doctos appointment scheduled ASAP so he can prescribe something for "stress"...
You could be having brass issues...I haven't been convinced that it (Nosler) is "good stuff"
I have used it on a 220 Swift and I don't see any improvement over Winchester...

I am working on a 22-250 AI (80-90 grn bullets) and it does NOT like a bunch of neck tension...
Anyway you will probably shoot the barrel out before you find the sweet spot..;)

Eddie in Texas
 
For What It's Worth

The hunting load I'm running right now is a 168gr Berger seated .080 off with Ramshot magnum. I loaded Nosler brass as it came out of the box. This is shooting consistant .4'' at 100. Savage 110e with Pac-Nor prefit headspaced for this brass. Very pleased with results on game, 3 antelope and 2 deer.

Job constraints have prevented me from doing further load development right now.

looking forward to reading more on this

Wyatt
 
Jackie,

Thank goodness now even a Benchrest Shooter can now understand how difficult it is to shoot a hunting rifle for groups!

None of my highpower hunting rifles like free recoil. Although I use a Hart rest with windage and rear bags I still hold on to mine with my right hand grasping the stock as if shooting in the field, along with a good enough pull into the shoulder, but not enough to cause the rifle to jump out of the rest. The PAST wearable shoulder pads are great, so are the accuracy assist things that attach to the front swivel stud.

I also don't believe in 5 shot groups. I switched to 3 shot groups years ago for hunting rifles. Once I think I've got're licked I will clean the barrel; then fire two foulers and try a 3 shot group when the barrel is dead cold.

Yes, custom barreled highpower hunting rifles can and should shoot 5/8" three shot groups off the bench.

BTW once you find the load, sighting in off the bench will usually not be the hunting zero. Most folks most often shoot higher off hand or off sticks etc.

Another suggestion is to try some of the very fine Nosler Accubonds. I find them very accurate and perform as good as or better then the Partitions on game.

Best wishes
 
John, I made Ed a rel nice Accuracy Assist out of black delren, (he is out of town and has not seen it), I have shot quite a few high recoil hunting rigs, I have a specific way I hold the Rifle, it has always worked in the past.

I may be expecting too much. I don't fool with this sort of thing that much, I tend to get all panicky when I see paper between bullet holes.

Anyway, Ed will be back after Cristmas, he can have at it............jackie
 
Jackie
My 280AI has a 25 in. barrel and a muzzle brake. I have found that it has two nodes it likes to shoot at. The best accuracy comes with enough powder to trash the primer pockets in two firings, but it puts all the shots in one hole. I decided I could'nt afford to buy that much Nosler brass so I backed off. At the velocities I really wanted it to shoot at I could not get the accuracy I wanted so I went lower and found another another sweet spot. A little slower then everyone else braggs about but it shoots well at the lower velocity so that's where i'm staying. What does 60 grns. of RL25 with a 168 berger or 175 smk sound like compared to what you were loading?
When ED wants to stretch it out to 600 or more come up to my place.
Mike
Mike
 
Mike, in Ed's 28 inch barrel, 60.5 grns of Reloader 25 went around 2850 with the 168 Berger. I loaded it clear up to 3100 with the R-25, but accuracy was terrible. None of the groups with R-25 were that good, probably in the .800-.900 range............jackie
 
Jackie,

I have an old 280 AI and while I have never killed an elk with it at 500 yards, I have taken three whitetail deer at 350 yards. All neck shots. For the deer I used Sierra 120 grain because the 165 grain bullets that I had loaded for Elk did not expand fast enough for Deer. If you could get a 4 inch group at 500 yards, you would have a 500 yard Elk rifle. In other words, if you could hit within 2 inches of where you aim you could bag the Elk.

Don't give up, Jackie. You are inspiring me.

Concho Bill
 
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