SLOW Twists and FAST Casts Using CUSTOM Barrels...Results, Please?

[tomme boy]

Tim, what make of the blanks?

[1johnlb]

sgt.mike


Attachment 134946
hmmmm ....... Look anything like this???


Are they spoken for? Or up for sale

[1johnlb]

Yes, brux quoted me 6 months. Can't blame me trying can you?

[Hannibal]

There is a 'surprise' or 2 in that bunch if I am not mistaken. THOSE are the ones I'm anxious to see on the range.

[Eutectic]

I've got an old Savage Model 342 that I bought over 50 years ago. For $35 !! It was my first varmint rifle and my first Hornet. I have always been teased unmercifully about how ugly it is! But it never took a backseat in the accuracy department! It has sat in the dark for over 30 years. But recently I brought it out again.... mounted a scope and have shot cast in it. It's still accurate!!

I've got a new lube formula. Not a spin off of anyone else's lube formula either. It has common components; just arranged different. All I'll say for now as this isn't the Lube Thread.!! And I'll test before I talk details. But I used it in the 'old Hornet' yesterday and today..... Why??

The lightning fast butter soft alloy load I used is a real 'lube tester'! If you can get 10 rounds through the barrel with speed and soft alloy together you have a tough lube! Reason I used this new formula. If it can't take it then it can take a leave.

I fired half a dozen plinkers fouling the clean bore of my old Savage yesterday. I kept four for this morning...

This ol' gun cold starts about 1 to 1 1/4" high with boring regularity but dependable to do it with several lubes. Mike's 666-1 cold starts under an inch.

So this morning I tried the lightning fast butter soft alloy load in my ol' girl...The NOE 225107 cast from 8.5 bhn alloy weighs 38 grs. hollow pointed .058" x 185" deep. I shot over the chronograph as well as the Model 342 has a short barrel.

The group is attached ... 85 yds. Cold start is the higher one. Next three were in a hair over 7/16"! Even with the cold start included it was a hair under 7/8"....... They chronographed 2823 fps...

Eutectic

[Larry Gibson]

Amazing what can be done with slower twists for sure.

Larry Gibson

[NC_JEFF]

As a very interested novice at shooting cast accurately in the rifle I have, do the paper patch guys use slower twist barrels or "standard" twist for caliber barrels? Or both?

[detox]

Larry, Have you tried softer alloys with your slow twist barrel? Maybe it will work?


BTW....I really like the looks of this rifle. Notice the barrel is clamped to stock. Much like a test barrel in a balistics lab. Is the receiver floated also?

[MBTcustom]

Larry, Have you tried softer alloys with your slow twist barrel? Maybe it will work?


BTW....I really like the looks of this rifle. Notice the barrel is clamped to stock. Much like a test barrel in a balistics lab. Is the receiver floated also?

Yes, the receiver floats from the block to the stock, the barrel floats in it's channel, and the scope rail floats over the action.
When I was building the rifle for Btroj, I offered to build him just such a rifle as you show in the picture but he declined.

[MBTcustom]

As a very interested novice at shooting cast accurately in the rifle I have, do the paper patch guys use slower twist barrels or "standard" twist for caliber barrels? Or both?

The easy answer is: Both
Jacketed bullets usually shoot best when they are spun just fast enough to stabilize at the maximum distance you shoot. Therefore, a discerning target shooter will choose a twist that stabilizes his bullet just far enough for it to punch a hole in the paper he is shooting.
That said, jacketed bullets allow the core to slip, this preventing damage so it is possible to over spin the living hell out of them, which makes them perfectly suited to factory twist rates, (although perhaps not really ideal for the 100 yard range).

[Larry Gibson]

Yes I have tried softer alloys. No they do not hold up to the velocities and pressures that #2 alloy and linotype stand up to. They simply can not withstand the higher acceleration. Earlier in this thread I posted results of two bullets of two softer alloys. You can readily see where they crossed the RPM Threshold and that they didn't give the best accuracy above 2400 fps.

Larry Gibson

[A pause for the COZ]

Wow!!! Bravo!!!
I caught this thread late and was amazed at what I have seen.
We are fortunate to have guys that can put in the hard work.
I do notice I have allot to learn.

I have noticed similar results but coming from a different end. Trying to get 223 cast bullets to shoot out of my 1-9 twist AR carbine.
kind of got it to work using a heavier bullet 75gr and keeping them in the normal speed range 1700fps or so.

Finally gave in and built a 1-12 rifle. Its a completely different animal.
I have 65gr boolits shooting good with out working too hard at all. And pushing them fast too.
I ummmm shot my Crony so I haven't tested them yet. But I bet they are zipping along in the 2500+ range.
Point is, just slowing the twist took an effort in hair pulling and made it a fun process.

Keep up the good work and I will keep reading it....

[MBTcustom]

Wow!!! Bravo!!!
I caught this thread late and was amazed at what I have seen.
We are fortunate to have guys that can put in the hard work.
I do notice I have allot to learn.

I have noticed similar results but coming from a different end. Trying to get 223 cast bullets to shoot out of my 1-9 twist AR carbine.
kind of got it to work using a heavier bullet 75gr and keeping them in the normal speed range 1700fps or so.

Finally gave in and built a 1-12 rifle. Its a completely different animal.
I have 65gr boolits shooting good with out working too hard at all. And pushing them fast too.
I ummmm shot my Crony so I haven't tested them yet. But I bet they are zipping along in the 2500+ range.
Point is, just slowing the twist took an effort in hair pulling and made it a fun process.

Keep up the good work and I will keep reading it....

If you'd gone with a 14 twist, you'd have been in the 2700FPS range, and if you'd gone with a 16 twist you'd be in the 3000FPS range.
If you haven't already, this is a good read on the subject: http://castboolits.gunloads.com/show...velocity-chart

[Hannibal]

hehe ok Darrin don't let the cat out yet... LMAO it might pee on your leg again (sorry could not resist that one after that text you sent).

But yes once the build is complete there will be some details covered by the builder (Goodsteel, even though I have not discussed this with him) that Expanman is alluding to.

Hey, it's all good! If a man can't laught at his mistakes then he's taking himself much too seriously, eh? LOL!

[detox]

Yes, the receiver floats from the block to the stock, the barrel floats in it's channel, and the scope rail floats over the action.
When I was building the rifle for Btroj, I offered to build him just such a rifle as you show in the picture but he declined.

The block/clamp would allow quick easy barrel /recoil lug/receiver change. Stiff scope rail is attached to top of block or receiver. Clamp/block is bedded and bolted to a stiff laminated wood stock. Both the barrel and receiver are free floated.

Goodsteel, Could you make and sell one of these barrel clamps. A simple V shape could be cut as channel to hold different barrel diameters.

[MBTcustom]

The block/clamp would allow quick easy barrel /recoil lug/receiver change. Stiff scope rail is attached to top of block or receiver. Clamp/block is bedded and bolted to a stiff laminated wood stock. Both the barrel and receiver are free floated.

Goodsteel, Could you make and sell one of these barrel clamps. A simple V shape could be cut as channel to hold different barrel diameters.

I certainly can and have.
But it's very dependent on stock design as to how deep, wide and long to make the block.
Also, I do not recommend making it a V bottom. Unlike a bedding block for the action, the barrel has no recoil lug to stop on the block, so you are entirely dependent on surface contact to keep the barrel from being driven back through the block. Also, you have to figure that you don't want to be applying three points of pressure in the barrel as it undergoes the stress of firing. The block works more by having a lot of contact 360 degrees around the barrel like a collet.
In contrast, the bedding block for the action is supporting something that has no radial expansion at all, and I would submit to you that you are pulling the action down into the V block rather than smashing it between another piece of metal.
That's why if I build a barrel block, I do so by boring a hole straight through it to the diameter the client requires, while it is bolted together the way it will be used, with .005 shims between the blocks to set up a small amount of squeeze. If I were to venture a suggestion, I would recommend going 1.200 as all barrel makers can supply this dimension.

It's an interesting concept that certainly creates a very repeatable harmonic situation in the rifle if built and used correctly. The drawbacks are weight, and it requires custom profiles that are parallel for a good 4-6 inches forward of the tenon, and it's costly to build and install (but then again, all custom work is).

[detox]

I may contact you about this. Here is a quick drawing with recoil lug attached in regular fashion.

[MBTcustom]

The size and shape of the block looks pretty standard. The trick is inletting the block, action, and barrel, into the stock so that everything lines up correctly, and your trigger dangles through its slot in the correct location.
The holes for the action bolts must be drilled out and a threaded insert installed so that short screws can be used to hold your trigger gaurd/bottom metal in place securely.
The stock itself may need modification and/or an adjustable cheek piece installed because the scope is held a good 3/4" higher than usual (depending on design).
Just a few things that need to be understood about doing a custom build like this.
If you want to jump in there, PM me and we'll start hammering out a game plan.

[Bjornb]

Range trip today, after finishing a house build that took about a year longer than planned.

Not too happy with the results, and a little unsure about what caused the less than stellar results. I formed about 330 XCB cases a couple of months ago, and accuracy hasn't been what I hoped for with these cases. In addition, my previous go-to powder, Winchester 760, has been out of stock lately and I've been using H414, which is supposed to be the identical powder. I just don't know.......

Back in December i shot this group with W760:

Then, in February, after forming new cases, I did a side by side test of old vs. new brass:

Still not completely shabby, and velocity was good. This is a load that spins right at 140K RPM, and has been consistent in my XCB rifle.

So when the groups looked like this with loads from 41 to 45 grains of H414 I figured it was time to go back to the drawing board:


I figured it's only fair that results less than stellar are also posted here on the forum; hopefully there will be improvements soon. I'm pulling the old brass down off the shelf, to see if the case batch has something to do with the poor accuracy.

The only positive development was the trial of IMR3031 in the XCB rifle; I shot a string of 12 shot with a load of 37 grains, aiming for about 2500 fps:

This powder is definitely worthy of further testing.

Happy Easter, everyone!

[dtknowles]

Thanks for posting.

Tim