OT: Bullet stability?

[Trailblazer]

I wanted to go deer hunting with my 1873 Winchester this year. I live and hunt in the lead free buzzard zone so I can't use cast. I bought a box of Barnes 44 XPB's to try. High priced bullet - about a buck a pop! Don't waste 'em! Barnes makes two versions of the 44-200 XPB. One for 44 mags that expands down to 1050 FPS and one for 44 Special that expands down to 850 FPS. I bought the 44 Special version but the cannelure is in the wrong place. I figured the simplest method to use to keep the bullet from being driven into the case in the magazine is to use a powder that fills the case and supports the bullet. I settled on IMR 4227.

I loaded three rounds last week to get velocities. One each at 15 grains, 16 grains and 17 grains. The 15 grain load did not read on my Chrony. The 16 grains went 897 FPS and 17 grains went 1030 FPS. This week I loaded five at 18 grains. They averaged 1130 FPS which is about what I wanted. All were shot at 50 yards.

The trouble is they show definite signs of tipping. The holes in the target are round but there is a dirty smeared tail on one side. The slower loads I shot last week showed a slight "tail" on one side but I didn't think anything of it at the time. The faster loads have much larger "tails". I don't get it. It looks like the faster loads are tipping more than the slower loads. There must be something else at work here.

The rifling is shallow and has a fine roughness - almost like worn 40 grit sandpaper. It shoots cast very well in spite of that. Twist is 1/36" .Groove diameter is .430" The XPB bullets are .428" to .429" and are somewhat longer than the cast bullets. I didn't see any copper fouling at the muzzle last week. I did not clean it because it always throws the first shot out of the group. That didn't work because it threw the first shot out even with the dirty bore this week. It does show copper on the tops of the lands this week. Accuracy is acceptable for a short range rifle.

The question is why would an increase in velocity cause the bullets to tip more?

[Bass Ackward]

It's not the velocity really. It's the fouling. You are shooting under bore diameter bullets in shallow rifling already.

So when the bullet sizes down to pass that fouling on the rifling, there isn't enough to hold bore center and impart proper rotation. The faster you run them, the more out of wack you launch them and you don't have enough RPMs to correct the unstable flight.

Pull up an old NFL tape of Billy Kilmer's passing and you will see what your bullet is doing. :grin:

[Trailblazer]

I remember Billy! Used to love to see him play!

I guess the copper bullet is a loser in the 73 unless I can find a deer really close. Not often the case where I hunt.

[runfiverun]

iirc they used to make some 430's in jacketed and someone made some 431's for the 444
marlin, at one time.
but unless you can find some 418's or so to paper patch, you may be outta luck for that zone.
maybe this is exactly what they had in mind when they passed this law.

[Bass Ackward]

I remember Billy! Used to love to see him play!

I guess the copper bullet is a loser in the 73 unless I can find a deer really close. Not often the case where I hunt.

Since this is going to be an ongoing problem year after year, I'd test it with some stuff designed to reduce fouling. Read this.

http://www.lubricationspecs.com/Whatsnew.htm

[mooman76]

How is the law on platted bullets?

[bobk]

This may be a stupid idea, but would this be a situation for thin patching? I'm thinking teflon tape, here. Also, even 4227 is not going to fill that case. I tried RL-7, liked it, but the velocities were higher than you want. What if you used a slow enough powder that it filled the case, but gave you 1200 velocity? As long as you're not smoking up the cases, it should be OK. The powder would be way outside it's optimum burning pressure, so mag primers, even mag rifle primers, might be needed to prevent cold weather duds.
Bob K

[Trailblazer]

Bass, have you used that stuff? Another one I saw is Ultra Bore Coat.

Plating isn't legal if you have a lead core.

I don't think teflon or any patching would work with the rough bore. Think sandpaper! A wad might do the trick but the 44 WCF case is bottlenecked so a wad isn't feasible.

4227 did work because the copper bullets are longer than normal. With 18 grains and the bullet seated against the powder I had a COL of 1.555". That is a little short but it fed just fine. It does leave a lot of unburned powder in the bore. I used Winchester Large Pistol primers and I wondered later if rifle primers wouldn't work better. It never gets much below freezing during season so real cold weather performance isn't an issue.

The lack of stability spooks me. Who knows what it will do if the bullet tumbles on impact. Bullets sometimes do funny things on impact anyway. I didn't test them at 100 yards either. They may not even hit the paper at 100.

I have thought about putting the bullets in the lathe and shortening them up a little. Make them 180 grains. I don't know if that would make them short enough to stabilize. Or just rebarrel the rifle with a faster twist barrel.

[leftiye]

You could try making your own bullets out of pure copper (since you have a lathe). That way, you'd get them the right size at least.

[runfiverun]

some copper rod will work,
there is also the option of getting some 45's from barnes and turning them down.
give barnes a call i bet they would send you 4-5 to try.

[Bass Ackward]

Bass, have you used that stuff? Another one I saw is Ultra Bore Coat.


Yes. It will make a great difference if your bore is rough.

We use it to tell when a rifle is broken in cause it won't make an accuracy difference at that point. And in fact, accuracy can begin to go the other way.

For what it costs, what have you got to lose? Wipe it on and let it dry. If it fails, you have another very fine grade lubricant. Or use it to thin your LLA. :grin:

It is a thin oil about the density of a penetrating oil.