high velocity with 311413 Squib Bullets in 308 Win AR10.

[RoyEllis]

Bruce, here's a snippet from a post I copied off this forum. This alloy formula has worked out quite well for me, hope you can make use of the info.
copper alloy
Bullet Design: RCBS 30-180-SP (Late version, bore riding nose)
Actual weight lubed & checked: 190 grains

Cast of an alloy that is: (according to Badgeredd's alloy calculator)
92.35% Pure lead and other trace elements
3.73% Tin
3.5% Antimony
.22% Copper
.20% Arsenic

The easy way to mix this alloy is to follow this simple recipe of 8 lbs. Clip On Wheel Weights, 1.5 lbs. of Pure Lead, and .375 lbs. of Rotometals Grade 11 Babbit for a 10 pound pot. Double the amounts for a 20 pound pot and quadruple the amounts for a 40 pound pot, etc. Here's a hint, don't assume that your soft range scrap is in fact pure lead that's ok to use in this mix, it probably isn't. Use what this recipe calls for, don't deviate. There are enough variables to deal with in Clip On Wheel Weight alloy as it is. No need to have the other components skewed.

Bullets were water dropped from the mold into a five gallon water bucket. They were allowed to stabilize for two weeks, BHN was 28, sized/checked to .310" diameter and lubed with MML + 5% Soap. My mold casts a bullet nose that is .302" diameter using the above alloy from my mold.

The load itself is as follows: (loaded and shot as projected in Quickload)
46 grains of IMR-3031
CCI #200 Large Rifle Primer
54,000 psi / 100% powder burn / muzzle pressure = 7,849 psi

5 shot average over the chronograph is 2,510 fps

[popper]

I just use CuSO4 powder to replace tin/zinc in the alloy - add it to all my alloys so far, very good results. Doesn't take much. Babbit is good too but mostly tin - which I don't use. Yea, trying 300 - 600 you do need the pointy/long boolits for BC.

[Hamish]

Bruce,

There are a couple of different ways that are easy to get a balanced copper enriched alloy, both will get you into the sweet spot of 0.25 to 0.50 of one percent of copper in your alloy.

One pound Rotometals Number 11 babitt to 16 pounds COWW and 24 pounds pure lead.

My personal alloy is one pound number 11 babitt to 49 pounds of 50/50 range scrap/COWW, adding a bit of flux core solder into each ten pound pot.

Both of these recipes are per Edd. Copper enriched alloy is absolutely worth the negligible added cost. It produces a super tough yet malleable alloy that substantially raises the bar on what can be accomplished with a cast bullet.

[NYBushBro]

Phillip Sharpe wrote in his 1937 book "Complete Guide to Handloading" (Page 96) that he was successfully shooting the Lyman 311413 169gr "Squib" bullet in his 30-06 Springfield out to 2200fps with 1-1.25MOA accuracy off a rest in 10-shot groups using standard gas checks and his personal lube recipe. He further compounded this claim with his work with Hercules gunpowder's ballistics office where they got 2600fps with that same bullet/gas check and lube combo with no leading but didn't report the final powder load (He was using an now obsolete and out of production Hercules Sharpshooter brand gunpowder with psi values on the loads going from 33K to 55K)

Sharpe's personal bullet lube for high velocity work? Colloidal graphite in distilled water painted onto the bullet with a camel's hair brush and allowed to dry. Pre-PC but a unique way to prevent leading in his rifles.

Bruce

Has ANYONE thought of (or attempted) adding some colloidal (ie: 'microfine') graphite to their 'ASBB shake & bake' for rifle bullets? (ie: 'Phillip Sharpe 2.0').

I'm wondering whether it would 'bake on' as an additional surface coating. All comments (and/or experiment results) welcome.

[madsenshooter]

"It produces a super tough yet malleable alloy that substantially raises the bar on what can be accomplished with a cast bullet." Who'd have ever thought it! Hi Rich! Watching this thread, I got some interest in these squibb bullets. I have a couple different Belding and Mull 311169 molds. One has a nose with a little band on it. I see it's still there in their 1947 catalog. The other is more a 311413. I've got some of Henseley's version cast of a hard alloy too, though I sold the mold long ago. His original also had a band, even bigger than the B&M's. I've not gotten around to comparing the B&M that is more 413-like to the original. I did get to compare the Henseley and original B&M, the Henseley got wilder at a lower velocity, with the alloys I was using back then, despite having a band sticking right in the throat of my Krag. Henseley also went with a more 413-like design later. Back to alloys, I been shooting some 70gr 6mm bullets cast of the hard alloy @ around 2500fps out of my 6x45 AR with 1/10 barrel and enjoying it!

I could see 2520fps out of a Krag. That's probably about how fast the boosted caseful of 860 got my 168 BTHP going at Camp Perry a couple years ago. Poor performance wasn't due to the load. A Squibb just as fast? Can't hurt to try a few, long as you got a good backstop!

[Forrest r]

I would be concerned with bullet nose slump with those long pointy nosed bullets. Awhile back I did a little head to head testing with these bullets, cramer # 43's.
[IMG][/IMG]

All test bullets were cast at the same time/same alloy using a cramer 2-cavity mold that has 1 cavity plain and the other cavity has a hp pin. I do not use copper in any of my alloys but I did test several different alloys with this bullet in a custom bbl'd 308w. Didn't matter what I did when I got close to the 2400fps mark the pointy bullets accuracy started to fall off. This is what I consistently saw target after target.
[IMG][/IMG]

The hp/non pointy nosed bullets always shot tighter groups when approaching 2400fps and anything over 2400fps. Could it be a bad cavity??? Perhaps but I've never had any success with any bullet with that nose design and anything over 2400fps. I've owned several different 311413 molds in the past and finely gave up on them and sold them off.

Perhaps a copper alloy will hold up better to nose slump?

[Forrest r]

I also have a plain/hp cramer #50 mold, same bullet as the lyman 311359. Probably should do some head to head testing with them also.
[IMG][/IMG]

[popper]

2 problems when ou go fast with fast twist. Rotational speed vs alloy and nose shock wave (heat!). Sharp point to dissipate it or blunt nose which has a different wave and more mass to dissipate. Once out of the barrel, nose does the steering!

[Hamish]

[longbow]

Bruce:

I'll start be saying that I am no expert here at high velocity cast boolit shooting and I am sure most if not all the contributors to this thread have more experience than I do. I have not done what you are trying to do and I have not shot the 311413 so no personal experience here. Coincidentally though a friend lent me his 311413 mould so I cast about 100 to try. So, I will be interested in following your thread.

I have run into some issues when I have pushed some boolits of too soft alloy a little faster than my normal loads. I read the thread and saw comments about boolit hardness but I did not see any comments about oven heat treating.

Lead/antimony alloys can be heat treated to produce a maximum yield strength of about 12,500 PSI which is significantly lower than the chamber pressures you will be generating. Chamber pressure aside, what matters is the actual pressure on the boolit base. As stated in previous posts the push on the boolit is at the base and if the boolit yields it will yield from base forward until the mass being accelerated doesn't produce enough stress to cause the lead to yield.

Yield strength and hardness both matter and both are related. I'd have to dig out my old lead alloy manual to find the lead hardness at 12,500 PSI yield strength. If memory serves about 8% antimony alloy heat treated produces the strongest/hardest lead alloy you are likely to get and an internet search indicates that is true.

A weak point in the boolits is the lube grooves as there is less cross sectional area at the base of the lube grooves. Also, the gas check shank has reduced cross sectional area so is also a weak spot. Where the gas check is covering the shank the copper or aluminum cup will provide some support but the open length of gas check shank is reduced cross section and unsupported so a weak point.

I have recovered boolits that show compression and distortion in lube grooves and above the gas check. In fact I recovered some relatively soft Lyman 429421's that had totally collapsed in the lube groove. These were cast from a relatively soft alloy but not near pure lead. Any distortion of that nature has to affect accuracy as it is unlikely to be even.

Another thing to consider is "skidding"... that is the rotational inertia resisting rifling twist so swaging wider grooves in the boolits and allowing gas leakage. I have seen this as well in boolits recovered from my Lee Enfields when pushing 316299's a little hard and also with some boolits from a homemade mould. To solve this I oven heat treated boolits which increased hardness substantially and that stopped the skidding. I don't recall specifics but if memory serves these loads were around 2000 FPS so not particularly high velocity.

Point being that to achieve the highest velocity possible you will likely have to use the highest yield strength/hardest alloy you can get. Oven heat treating wheelweights may do it but I suspect you will need something higher in antimony and/or other alloying elements. Even type metals seem to top out in the mid to high 20" BHN. Some babbitt alloys are listed with BHN into the high 20's and low 30's so may be suitable.

That's all I've got. Good luck! I'll be watching with interest..

Longbow

[madsenshooter]

That's running close to what I use in the 7.5x55 for Sierra 168gr Tipped Matchkings Rich. Now that the subject has come up, I could see that original B&M with its little .305" diameter band fitting the throat of my .294" bored K31. Shortest necked 30 I have. Tightest throat to deal with too. The .294 bore would add some support to the nose. I've been mixing alloy, I'll be sure to get some of both varieties of 311169 that I have cast!