What velocity can be obtained with plain-base cast bullets?

[Naphtali]

For me a good analogy for what I am attempting to ask is the difference between a drag racing automobile versus a Formula One Grand Prix machine - that is, speed with accuracy rather than speed.

Using plain base cast bullet in a single shot rifle:

1. What lead mixture would be expected to achieve highest velocity [range] while retaining accuracy?

2. What would be that velocity range?

[leftiye]

Depends (velocity). Lube matters (this should be a no brainer, but they's lossa mo mos out there who say it doesn't). Alloy will have an effect (see HV cast thread - it's not just harder is better, alloy needs to work with rest of load). Powder chosen will too (use best powder for mild pressure rise. Probly a slower powder which gets high velocity with low pressures. No, it's not contradictory). Probly primers even (milder primer will help, or poor ignition will mess up accuracy). Maybe large pistol primer (std.).

[Hickory]

Plain base boolits normally max out at around 1600 fps.
Two main things to keep track of;
1) Fit, your boolit needs to be at least 0.001 over groove diameter, in some guns it maybe more.
This is one of the things only you can find out by experimenting with.
2) Alloy. Most guns operate a lot like Goldylocks in this respect, not too hard, and not too soft, it needs to be just right for your gun, but if you want max velocity, it will have to be on the hard side.
And this is important also, boolit lube.
The proper boolit lube will give you higher velocity with little or no leading and will also have an affect on accuracy.
I always considered these steps as "getting to know your gun."

[Digital Dan]

Naphtali, your question is broader than you realize perhaps, and a bit too discreet as it gives no clues as to application. "Single shot rifle" covers all the ground known to the shooting community.

Pure lead can go faster than you might imagine if wrapped in a paper patch. I've done 1800 fps that way. I have done the same with plain base bullets with hardness in the 10 BHN range with a 1/4 bore and found good accuracy. My personal perspective is fairly straightforward. Cast it, shoot it and if you don't like the results, make an adjustment to one or more of the many variables involved.

Velocity is over rated. Drop is the easiest factor to contend with at longer ranges, wind the trickiest. The God of Ballistic Performance I kneel before is the terminal equation.

http://img.photobucket.com/albums/v298/muddler/Guns/PaperPatchDeer009_zps3a52d58c.jpg (http://smg.photobucket.com/user/muddler/media/Guns/PaperPatchDeer009_zps3a52d58c.jpg.html)

[GabbyM]

My experience has been. Larger caliber bullets in plane base can be driven faster than small calibers. 38-55's seam happy shooting plain based 255gr bullets at over 1,700 fps. 22 center fire rounds are just good for 22 RF velocity. 30 caliber seams like they only want about 1350 fps. Things like barrel twist rates play into the end results as well. Much more complex than just what's on the base.

[44man]

Agree, don't know until you experiment. I shoot over 1600 with a PB and have shot the .454 to over max with them, no idea how fast I got, too lazy to set the chronograph.
I use water dropped WW only.

[dtknowles]

In my .22 hornet Ruger #3 I have shot the plain based NOE 45 gr. .226" flat nose bullet at up to 1800 fps without noticeable leading. The accuracy does start to drop off above 1600 fps but is still less than 2 MOA. 50/50 range scrap/COWW sometimes with a little tin added sometimes just range scrap. 50/50 Alox/Beeswax lube.

Tim

[mnewcomb59]

I have good luck in Rossi 357 rifles at 1800-2100 fps. Lee 158-RF WDWW tumble lubed, sized 359, tumble lubed again and then visual sorted for good bases.

They have such a slow twist rate that the drive bands are biting the riflings with low stress, while the lube groove is deforming and pumping. Basically the twist is so slow that the bullet is deforming more front-to-back than side-to-side.

Imagine biting deep into a bullet with pliers, then INSTANTLY spin it to 120000 RPM. Soft lead might get a waist shaved off by the pliers teeth, while harder lead might hold the teeth. The less RPM you can accelerate a bullet to and maintain stability the better.

Here are some examples to demonstrate how slow the twist is and therefore how low the rifling stress is on the bullet:

If you were to calculate the RPM of a 30 twist at 2000 fps, it is still less RPM than a 16" twist Smith/Ruger revolver at 1100 fps. AND, it has 4x the barrel to gently accelerate to the RPM compared to a fast twist pistol.

I could shoot a bullet at 3000 fps in the rifle to make the same RPM as a 10" twist 9mm at 1000 fps. This is why 9mm usually needs hard lead - it has a faster twist than 357 mag.

I get 1 MOA believe it or not out of this gun. I did have to firelap about 20 shots to smooth out tool marks, and I sanded the forearm where it touched the barrel. One windy day at the range it blew out of the rifle rack (looks like a pool stick rack) and landed on the muzzle. I recrowned it with a brass screw and lapping compound.

134275

16.1 Lil Gun is at least 1750 fps. 17.4 shoots just as good at 1875 fps. 18.6 (Brian Pearce data) is almost 2000 fps and shows promise. I experienced some vertical stringing which was probably because my eye was not perfectly centered in the scout scope (parallax).

This spring I'm gonna work on the 18.6 load some more and hope to find it is just as accurate as the lighter loads. Then, I'm gonna soften and soften the lead mix until accuracy degrades. My softest mix is around 9 BHN air cooled range scrap with hard cast bullets picked out before the smelt.


I shot this 9BHN alloy, lee 125 RF at about 2100 fps with no leading (what does that tell you about slow twist rate and cast!?), but mediocre 3-4 MOA accuracy. I recovered some bullets and they expanded a lot. I could see the riflings holding tight, no gas cutting in the grooves, and the lube groove was entirely swaged out. The bases of the bullets were cupped deep like half way to a hollow base, and my hypothesis is the off center sprues made the bases cup off center, throwing off accuracy. Not a speck of lead in the barrel.

A lot of guys have good luck with full powered 30 carbine because of it's slow twist. 32 win special can get 3 MOA or better plain base around 2000 fps. Guys have good luck with 444 Marlin as well.

[Naphtali]

Many thanks, guys, for your replies. Although I have a much better idea of parameters, I'll be enjoying weeks of futzing until I'm satisfied with results.

[jhalcott]

Pure lead 55 grain .225 bullets in a 30-06 and a sabot have been shot to near 3000( thousand) fps. Less than 2" groups at 100 yards.

[10mmShooter]

As stated your question is very board, please be more specific such as caliber and weapon.

I run all plain base bullets from .32 swl to .357/10mm/.41/.44 ... I run my fastest at 1500 fps in my .44 Henry sized at .432 with 15 grains of #7, with no leading, my alloy is at 14 BHN.

[rintinglen]

You can shoot really fast--if you don't mind inaccuracy and leading. Best I've ever managed with a bare plain base boolit and acceptable accuracy and minimal leading was near 1700 fps in a 45-70. I have invented the rifled 30 caliber shot gun by running a PB 311-410 at 2100 fps from a 30-06.
Now, if the boolit does not touch the bore, either because of a sabot, a paper-patch, a plastic coating, or some other such mechanism, life changes. Put a jacket on it and you can shoot it just as fast as jacketed.

[Harter66]

I am quite the rebel on this 1 . More info would help.

I have run an unchecked 27-130 up to 2350,papered . I have also had a 32 Rem up to 2150 with with a naked plain base . I've not checked any pistol carbine loads getting high 1400s from a 357 and 1200 with a 45 Colts. I get into the 1800s in assorted 30 calibers .

[tonyjones]

There are several members here who, using Cu as a grain modifer and water dropping, have attained 1,800 to 1,900 fps mv with good accuracy reported. This was with plain based cast bullets; no paper patch, gas check or jacket. TJ

[John Boy]

Napttali ... It depends! One would have know the powder charge: smokeless - black powder or duplex ... caliber and bullet weight
Be specific for one because if you want to know for calibers you don't shoot - the reply will be a loading reference manual exercise

[cajun shooter]

I would suggest a good comfortable chair and the book that is offered to all members for free on our forum. The book was written by Glen Fryxell and Ron Applegate. It is named "From Ingot To Target".
It will provide a good background on the alloys we use and how to use them best. Later David

[KAF]

25-20 single shot, 120gr bullet, Breech-seated 1/16" in front of case,my home made lube, card wad , IMR4227, starting at 9.5 grs,working up, 1/2 gr at a time, 25-1 alloy, started to get a trace of leading at 1750fps.

[Doc Highwall]

I would like to know what is called good accuracy and at what distance and with how many shots? What kind of gun and what kind of sights, scope, peep or barrel sights?

As has been mentioned bullet fit, alloy and lube make a big difference but loading dies and technique have not been mentioned.

[RobsTV]

When I asked a similar question here a few years ago, most experts here suggested that it is more than simply velocity determining if a gas check is needed, and seems most replied that normal high pressure rounds also require Gas Checks. Keep it much less than 1400fps they said. No one mentioning pressure this time?

My advice is try it and see for yourself how things work out, then make adjustments if needed. Also, you can always add a gas check to a plain base boolit if desired, and it will perform just as well as if you used a mold with GC shank and traditional GC's.

Also, powder coating should be able to allow faster boolits without gas checks.

[quilbilly]

I have a 357 max TC carbine and picked up a Lyman 173 gr SWC-PB for cheap at a show. Sizing to 358 and lubing with Lee Alox, I started slowly working velocities up from 1100 fps until leading appeared. At 1450 fps I saw the first sign of leading. None was at 1400 fps. My alloy is 60% pure, 36% birdshot, and 4% tin plus is water dropped. The birdshot is hard chilled so provides the needed antimony and arsenic for a boolit that gets excellent penetration without breaking up. In round nose boolits used in my 6mm, 7mm, and 30 calibers, expansion with this alloy is wonderful.