Q:

Cast bullets, power and frame flex, a thin precarious line

I shoot long range, 150 yards and further with cast bullets in the AF platform.

I use a dechoked LW 25 caliber barrel, a custom stretched Talon SS frame, a heavy spring and hammer to power a Dyotat valve and cast bullets from 56 to 75grains at 115 to 125 FPE and I do it tethered usually around 3400 PSI.

I get groups at times around MOA for 5 shots at 150 yards and at times 285 yards. I will paint 6 small dots on a 3×4 sheet of black painted steel and shoot 6, 5 shot groups, go down and measure them, re paint and do it all over again. When everything falls together, I take a picture of them and post them for you.

Problem is they are not consistant, one group will be 1.75 inches and the next under identical conditions will be 5 inches. It is frustrating beyond belief.

One day I will get very tight groups, think I am on to something and the next outing it all goes to shit again.

I get a lot of PMG’s and emails from shooters wanting to know how to modify their Condors to shoot cast bullets at high enough FPE to be accurate at long range.

I explain to them they need to get a unchoked barel, or cut thier choke off, a bigger valve, Dyotat’s 25 caliber valve on your body being the best IMHO, a higher fill pressure and to open that big valve against the high pressure, a stronger spring to power a heavier hammer.

The problems is, the AF platform, as WOK likes to mention was not designed for this, and he is right.

The frame has flex problems, and again WOK has pointed this out in the past by telling us to put a laser on the rib of the tube and then shoulder the rifle with a strong grip and watch that laser dot move against the crosshairs.

Now I read folks who say they have not problem with POI change induced by frame flex, but they are not shooting 150 yards with 75 grain cast bullets powered by heavy hammers and springs, in short they are using their rifles for what they were designed for, 65 FPE and under.

And they have not done the laser test.

Problem is for long range you need cast bullets, Diablos don’t cut it, and you need high FPE, the AF platform has trouble providing this. You need 115 or more FPE to resist wind drift and reliably throw high BC cast bullets down range for any consistant groups.

Simply put the frame is flimsy. It is light aluminum, has dimesions that vary badly, has a poor barrel mounting system and a Power wheel cutout that is nothing but sucidical for frame/barrel integrity.

Before you get all hot under the collar, ever look at a benchrest PB or a Hi power competition PB?

They carry heavy thick barrels and they sleeve the actions, if it is a AR 15 based rilfe, it has a heavy barrel and a tube forearm. The AF platform has none of these action and barrel stiffeners, the tube on the AF does not float the barrel like on a AR, it bears directly against the barrel bushings and thus moves the barrel when the frame is flexed.

Practionors of those disciplines would laugh at the AF line and the flimsy components, these flaws result in the frame flexing when held in different postions between shots or shooting seccions, and vibration and stress directed towards the barrel by the impact of ultra heavy springs and hammers.

The frame needs work, the hammer spring system is what it is, it is how the rilfe works and can’t really be changed in my opinion, and every single time I step up to heavier hammers and heavier spring, power goes up and accuracy goes south.

Part of these problems can be remedied thru strengthing the frame. For conventional use, ie, what the rifle was designed for, the WOK guard works very well, the Maddog stock does better yet if you can live with how it changes the balance and looks of the rifle.

But none of this fixes the impact of heavy hammers and springs and how that stress relates to groups at long range.

I have this week tried putting a AF Tri rail on the carrying handle and on the rib in place of the forearm, I saw no improvement.

I think the cottage industry needs to step forward and create a stiffing system that either replaces the frame with a steel tubed frame without a Power wheel hole, which is a serious defect in the integrety of the frame or a thick unflexable Picatinny rail that will run the full length of the under and upper ribs. Or a WOK type guard that either extends to give a free floating forearm and hopefully is made of steel.

But in the end what we need is a stiff steel tube with fire control rails made of steel welded on.

Problems is there are not enough buyers to make this feasable at a reasonable price point, perhaps as this long range game becomes more popular that will change.

All this is heavy, and will really change the ergonomics of the rifle, but for long range shooting at targets this is a good trade off in my opinion.

The power is there, Dyotat has provided that in a reliable remake of the valve for 25 caliber bores, we now need a better aftermarket frame.

I look at fully supported Maddog stocks, and I look a slightly stiffer TJ barrels, but I just can’t justify the finacial outlay when I can get a Haley Scandalous that will shoot circles out of what I have come up with so far and is made from the start for long range with cast bullets and is in the same price range once everything is bolted on a AF platform purchased for that purpose..

I am not saying throw your AF rifles in the junk pile, if you want more power, use Dougs valve, a slightly heavier hammer and spring put on a WOK guard or a Maddog stock, use Jerrys slugs and be satisfied with 100 FPE, because right now, with what we have for frames, your throwing money towards the wrong platform.

Regards,

Roachcreek

Mods/Machinists

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Viewing 4 replies - 31 through 34 (of 34 total)

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quote aninias:

I just took the condor outside to test this frame flex theory with the laser and sure enough it flexes side to side without much pressure at all.

The only thing I can think of that might be somewhat of an easy fix would be to machine off the topmost rail to get one even rail all across the top part of the frame. After this is complete, drill and tap holes into the existing dovetail and mount a solid m1913 rail piece and just possibly add some rigidity to the frame.

While removing the top portion of frame you would also have to make the gun a side-cocker to be able to run the rail all the way from the front of the gun to the back portion by the valve.

All of this in turn would cause some issue with scope mounting but I’m sure that is something that could be easily overcome with extra high rings or by dropping the tank down.

What do you guys think?

Something like this…

I have a feeling if and when I get a .257 TJ barrel, this will be the frame it is going to go in…I can’t imagine this will have any frame flex. The left side of the breech is filled in solid as well….[/img]

I just took the condor outside to test this frame flex theory with the laser and sure enough it flexes side to side without much pressure at all.

The only thing I can think of that might be somewhat of an easy fix would be to machine off the topmost rail to get one even rail all across the top part of the frame. After this is complete, drill and tap holes into the existing dovetail and mount a solid m1913 rail piece and just possibly add some rigidity to the frame.

While removing the top portion of frame you would also have to make the gun a side-cocker to be able to run the rail all the way from the front of the gun to the back portion by the valve.

All of this in turn would cause some issue with scope mounting but I’m sure that is something that could be easily overcome with extra high rings or by dropping the tank down.

What do you guys think?

Very good point Charlie. And when considering your words it is important to remember that you are talking about (as you pointed out) the long range game. When considering what these rifles were designed for (small game hunting out to 60 or so yards) one cannot deny that they put the heaviest smack down out of the box at a decent price point compared to other rifles on the same platform.

Yes, I would love to stop putting money into this “long range AF quest” and simply save up for a JH .257. I didn’t yet do that for two reasons. First (as you) I love these rifles and will hold onto the hope that they will—via all of the testers (like you, wok, tof, etc) and tuners (tony, doug, etc.) that put blood, sweat, and I’m sure tears into this platform—take their place in the annals of long range air gun shooting! Second, I don’t have a compressor and I don’t feel like driving to the firehouse once every other day to fill my CF tanks. If I can have some long range fun and contribute to the quest for consistent LR groups, and not have my fill tanks sucked inside out…then that is were I will be content to stand for the time being. I understand your frustration as I have experienced the same difference at the 100fpe level at 80 to 110 yard sessions. I look forward to seeing what kind of improvements are thought out (as you suggested) to resolve this frame flex “bug”. Incidentally, I always wondered about the area connecting the barrel leade in to the valve—the breach—as a weak link (for consistency) in this set up. I am no machinist, nor smith…just someone who thinks intuitively quite often. I could be wrong. Anyway, nice post! 😉

Personally, I agree with you Charlie.
I am sure people have different experiences with their rifles but in my case I had to own 5 AirForce rifles to realize what you just described.
I still really like the rifles and how modular and modifiable they are but I could never get them to shoot consistently accurate. Every time I owned one I felt I wanted to give one more shot to get them the way I like it but after trying many things with each of them, I just gave up. It would shoot one holers and then after the next fill the POI would shift. Even after I made one piece stock, I still couldn’t overcome the problem.
The third rifle I owned held zero for longest time until cold weather arrived and then accuracy went south.
I still love the platform and looks of the rifle but maybe my expectations are too high for this rifle or maybe I just suck at shooting:)
I moved on to other rifles that I shoot much better but still wish sometimes to buy enother AirForce in hopes that it will be the one.

Viewing 4 replies - 31 through 34 (of 34 total)

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