90gr Berger VLD and the 223 - 500m Group 1 1/16"X 1/8" see post 357

I'm quite sure there is a 1-7.7" krieger that won't stabilize the 90 vld in Ottawa- Perhaps Manitou can fill us in. I've been talking w/ Rock, and they'll make whatever twist one wishes. I'm thinking a 1-7.3". It might seem like nit picking, but Jerry Tierny has reported that the 7.5 twist he was working with was easier to tune than the 7.0, but the 7.0 could be a bit more accurate. I'm at sea level in NB. I figure that anything I can make work here, should work anywhere.
 
mysticplayer said:
Some have reported some really bad issues with vertical. This is likely powder/temp related. Maybe it is not????

Jerry
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Basic physics Jerry... That's the point.

A small variation on a small cartridge is the same as a large variation on a bigger one...

You can control powder charge to .02 grains for either 25 grains or with 50grains, but that means the powder charge for 50 grains is twice as accurate as the powder charge for 25 grains. No powder development will ever eliminate that reality.

Case in point Paul did everything possible with the 223/90 in 2010 ORA and he did very well at close range, but not so good at the back. It's certainly not because he cant shoot, the guy is awsome.

Rifle building is always a fun exersize, but I caution you guys not to set your expectations too high for this. It's a fun light recoiling rig and a pleasure to shoot, so if you have a hankering to build one, be my guest. $5000 later you will have all the answers you paid for. Worse case scenario is that you will have a fine 300-600 yard rifle, and that's just fine as long as you know it going in.
 
What I am looking for in powder development is continued stability due to temp.

I think the big issue with 223 tuning isn't the prep but how the load reacts to the ambient conditions.

If load tuning should stay within a narrow 'weight' range but the powder acts differently at one temp vs another, you can never keep the rifle in tune.

I use the SR BR analogy of loading at the match to help with this issue. We don't have this luxury in F class.

So we need powders that will keep their effective load over a wide range of temps.

the Hodgdon extreme does this very well and I use shoot the same load from freezing to plus 30C. There is very little vertical in my loads out past 1200yds.

What we don't have is an ideal burn/energy powder that can give us both stability AND speed.

What powders were these shooters using when they had their problems? I see Viht powders suggested almost all the time. This stuff is not temp stable so I have been told. So if they are loading this powder, of course, they will have issues.

I think the real question that needs to be asked is will the bullet go the distances without problems. Can you get the 90gr VLD get to 1000m without vertical regardless of speed.

As to spending $5000 for a rifle, I think you know that I am spending no where near that sum for my build.

mpwolf, I sure hope that 0.3 twist is not needed to set up this bullet. That would be way too finicky. 7 twist should resolve any stability issue due to ambient conditions. We shall see.
Jerry
 
fclassguy said:
Case in point Paul did everything possible with the 223/90 in 2010 ORA and he did very well at close range, but not so good at the back. It's certainly not because he cant shoot, the guy is awsome.
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You are correct Paul was shooting just fine at the ORA's but had an everyman moment...(everyman turns the scope windage the wrong way.... at some point) Had it not been for this oversight he would have made Sunday and given the contenders a run for their money..

If i recall he has his set up working real well and it is in part because of him that others are looking at the 223/90 combination.

All the best
Trevor
 
x2 with trevor

i belive that you will be seeing a lot more of the 223 and the 90 this year and the years to come,i for one have the barrel on order.

i agree with trevor about paul at the ora i was their and he was doing very good until uno what we have all done ones or twise or three times in our live turned the dial the wrong way...i know all to well about this did it at the nationals in the fininals at 800 dum a.s ,what can you do or say it happens.
Darin
 
My approach would be to sacrifice a bit of velocity for consistency and temperature stability and try the new IMR8208. The kernels are very tiny compared to H4895 and Varget (~1/4 the size, maybe less), similar in size to H322. The smaller kernels will allow for less error in the charge weight and the powder is extremely temperature stable.

The additional 100 fps the fastest powder (Hodgdon data) gives you is only netting you 0.7 MOA less wind drift (10 MPH, 1000 yards), which is a trivial gain if you aren't getting the consistency you require.
 
I am waiting for my new Shilen to test some H4350 style 'ball' powders. In my testing and those of other shooters, H4350 has shown to be superbly accurate, stable and zippo for vertical.

It's just slow in most rifles.

Varget gets you the speed but you run lower charge density and possibly higher pressures. In my rifle, this also shot very well but I prefer a full case.

IMR8208 has a pretty fast burn rate and with low charge density may not be ideal at dealing with the vertical side of tuning. Never shot it so just speculating.

So far, the best balance of speed and pressure have been the Viht 550 and 150 which are right in between Varget and H4350. However, temp stability is in question.

What I want is the performance of Varget, tuning ease of H4350 (and it is a gem to tune in this set up), and speed of Viht or dare I ask - more speed.

You are absolutely correct that load consistency and accuracy overrules pure speed. You can't miss fast enough to win. But I am looking for that holy grail where you can have it all.

At the present performance, the 223/90 matches most common 308 set ups. What I want is to beat the 308's ballistically and we are so very close to getting this done.

I am involved in a bunch of new 223 builds for F class. These shooters are interested in coming out to play but simply have no interest in the costs and recoil of larger options. We should see a significant growth in 223's on the line in BC.

I can only assume there will lots more all across Canada.

Do I 'dislike' the 308? Nope. Except for the recent 6.5's for F class, I had built more 308's then any other chambering over the years. Shot ALOT of this way the heck out there.

But bullets drive F class and the new 22cals are offering the best of many worlds. Potentially better ballistics, way lower recoil and costs. Greater opportunity to include kids and wives/girlfriends into the sport.

And I have even heard the 22cal hole could be scored with a 8mm template...

What's not to like?

Jerry
 
mysticplayer said:
At the present performance, the 223/90 matches most common 308 set ups. What I want is to beat the 308's ballistically and we are so very close to getting this done.
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The 223 only had a chance against 308 ballistically when the 308 was limited to 156 gr. bullets. With that rule gone, there is nothing you will launch from a 223 (with current powders) that will even come close to the ballistics of a 208 AMAX lauched at 2600+ fps. out of a 308.
 
wapitiwhacker said:
Jerry, have you considered N140 as well as N150? If not why not? My info shows the N140 slightly slower than the N150 but still between Varget and H4350. Curious, as I have a couple of lbs. on hand.
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I have not used any Viht powders as it is very difficult to get locally and will always be very expensive. But it is certainly worth a try if you have access to it.

I have seen N150 used in a TR rig, and WOW, it shot superbly.

kombayotch, shooters have been hotrodding the 308 for a very long time BUT there are many 308's that will not shoot accurately at these elevated pressures.

I have tried over several rifles to get the 3000fps from a 155. I got the speed but certainly never saw the accuracy. Should have been a no brainer but it never worked for me.

So there is a real chance that the 308 will only shoot accurately at 2300 to 2400fps which is similar to SAAMI. Now the 223 has an advantage.

One thing that will never change, the 308/200+gr shooter will have to put up with ALOT more recoil and barrel heat. For some shooters, that extra boot can start to fatigue them later in the match. Some will develop a flinch.

If you can put up with the abuse, great but it will always be easier to drive a set up with less recoil. The 223 will boot with 1/4 the recoil. That's a tangible advantage.

Wind drift at 1000yds from JBM software. Bullet from achive (Litz) data. No other changes to parameter.

90gr Berger VLD at 2850fps 81.4"
208gr amax at 2600fps 80.2"
208gr amax at 2400fps 91.7"

Personally, I think 1.2" less wind drift will be hard to see vs the task of controlling such a bucking bronco. Made even worse if you can't get the speed.

YMMV

Jerry
 
Not sure where you're getting the elevated pressures idea from... I can measure pressure, and have gotten the 208 AMAX up to 2650 fps. while staying under 58k psi with a standard length barrel. With a longer barrel, it'll easily add another 100 fps to that, and I can assure you that the bullet does shoot accurately over 2400 fps.

P1050229.jpg


These were all at around 2580 fps., which is where the accuracy node was. Others with longer barrels are reaching the node that's above 2700 fps.

While I agree that things like lower recoil are an advantages, it's beside the point. The statement that the 223 load will beat the 308 ballistically is false. You're comparing the optimum possible results you can get with the 223 to handicapped results from the 308. When both put their best shoes forwards, the 308 comes out on top, speaking purely in terms of ballistics. But the winner is the one who shoots the best, not the one with the best ballistics or even the most accurate rifle.
 
mysticplayer said:
One thing that will never change, the 308/200+gr shooter will have to put up with ALOT more recoil and barrel heat. For some shooters, that extra boot can start to fatigue them later in the match. Some will develop a flinch.

If you can put up with the abuse, great but it will always be easier to drive a set up with less recoil. The 223 will boot with 1/4 the recoil. That's a tangible advantage.
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BINGO! Well put, Jerry.
 
kombayotch said:
While I agree that things like lower recoil are an advantages, it's beside the point. The statement that the 223 load will beat the 308 ballistically is false. You're comparing the optimum possible results you can get with the 223 to handicapped results from the 308. When both put their best shoes forwards, the 308 comes out on top, speaking purely in terms of ballistics. But the winner is the one who shoots the best, not the one with the best ballistics or even the most accurate rifle.
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As I said above, there are times when barrels dont reach their fastest potential, in any chambering. Then some go faster.

At 2600fps, the difference between the two is moot. 1.2" is certainly within the error of BC calculations on any given day.

If you can go 2700fps, then you will shade the 223 by a couple more inches.

Assuming of course, that the 223 does not go faster or we don't point the bullets :)

The key is the shooter and how well he or she is driving on any given Sunday.

F class targets are pretty big by accuracy standards but pretty darn small if you are having a bad day reading conditions.

And that is what will separate the top shooters..... as it should be.

Looks like you have your rig working very well. Enjoy next season...

Jerry
 
I will let you know in the new year how the 1- 7.5 works at sea level as I have a 29" Kreiger on order for my new Barnard action. The barrel will be throated for the 90 VLD's. I know most recommend a 7 twist but I like to be different and push the limits.

My rifle will be a 223/308 switch barrel. If I can't stabilise the 90's in my 1-7.5 Kreiger, I will shoot 155.5 & 185 bergers out of the 308 barrel for the 2011 season until I can rebarrel. I couldn't decide If I wanted to build a 223 or 308 so I decided to have both and build a switch barrel.

Hungry here: Whoops, I hit the wrong button. I wanted to quote you on the switch barrel project which I have on the go right now with a 1 in 9" twist barrel and a .308 barrel ready to switch up.
 
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A dumb question from one not familiar with the F-class rules.

Since the issue seems to be getting the 90gr bullets up to high enough speeds to compete with the .308, couldn't you just use a bigger case like the 22-250 and not hot rod it so much? That would allow load tuning at lower pressures with stable powders and should eliminate your vertical issues related to temp sensitivity.

Or am I nuts?

Mark
 
There are two divisions in F class. Open and TR.

TR only allows 223 and 308 cartridges but no limit on bullet weight.

Open, allows most any chambering and cals up to 8mm.

So a 22.250 could be used in Open but not in TR.

Jerry
 
mysticplayer said:
Look forward to hearing how you make out. That will definitely define one end of the stability equation.

What powder are you thinking of using?

Jerry
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I intend to use Varget & H4350 to start out as I have both on hand. I am hoping to find an accurate load around 2850 FPS. I may try some VV if I don't have any success with these Hodgon powders.
 
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