Cast Bullets for T38

[daboone]

I have a T38 (long) that I like to cast bullets for. I have searched Cast Boolits. The only mold I have seen that look appropriate is the Lymans 266469.
If you are casting please tell me what has worked and what hasn't. Yes I have slugged the bore. ;-)

Information

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[Thumper]

I shoot cast in mine, I get my bullets from Moyers Bullets in Pennsylvania

First rate bullets, nicely cast, good lube.
I have NO problem with leading and they shoot very well. Most often I get very good groups with an occassional flyer.

I shoot .312 and .313 sized with a gas check.

If you are going to cast your own, I would go with a bullet with a long bearing surface and gas checked and you should be good to go


Bob

[Bruce McAskill]

The T38 does not take well to cast bullets. The T38 uses Medford rifling instead of conventional types. Results with the Meford rifling and lead bullets has been disappointing to say the least. The T99 does not use Medford rifling.

[Thumper]

Sorry I did not know about the differences in rifling.

[Bruce McAskill]

But in your T99 cast bullets should do a good job with the conventional rifling. Have you found a nice load for your T99?

[Thumper]

Right now I am working with a 180 gr bullet from Moyers using 24 grain of 3031. This shoots very low but very good groups. Extremely mild load, I am going to try and bump it up a bit.

So far, I am encouraged

[Patrick Chadwick]

The T38 uses Medford rifling instead of conventional types. Results with the Metford rifling and lead bullets has been disappointing to say the least.

Dear forum members, I think it is time for a bit of basic thinking about this topic. So please bear with me as I make a highly relevant diversion into the world of target shooting with military BPCRs.


First off, let me admit that I am, regrettably, talking without practical experience of shooting cast bullets in a T38, for lack of a suitable mould with which to try out that which I am about to propose. But I do have considerable experience of shooting black powder cartridges in calibers from 7.5mm Swiss revolver up to .577 Snider, at ranges from 25 meters to 1000 yards. And the very first observation I wish to make on the subject of Metford rifling is that it was developed for black powder shooting with lead bullets. William Ellis Metford (4 October 1824 - 14 October 1899) was an engineer of the "steam and black powder" age, and the rifling was developed to reduce fouling in BPCRs.


In a well cared-for black powder rifle, fed with properly lubricated lead bullets, there is just about zero wear and leading. For two principal reasons: 1) after the first shot, known for good reason as the fouling shot, the bullet is basically "crud-riding" i.e. it rides down the bore on the layer left by the preceding charge, and 2) the bullet travels with a very moderate velocity by smokeless standards, so there is very little (if any) stripping of the bullet when it is forced into the rifling. At witness to this claim I cite Harry Pope, who over decades fired a six-figure number of bullets from the same Shuetzen rifle.

While target shooters may be able to clean the bore between each shot, thus weakening point 1), military shooters cannot do so, and if you want to shot a full competition round without the bore coking up like an old chimney, adequate lubrication is a must. And the bullet must be of an appropriate hardness - too soft, and it may be stripped by the rifling - too hard and it will not fill the rifling properly. But in all cases, the hardness must suit the combination of bullet diameter, bore, and charge.

Gas-cutting and blow-by are not a problem with a good BPCR bullet, because it is propelled by a hydraulic seal formed by the lubricant. The Metford rifling was devised to avoid the tendency of sharp rifling to accumulate hard fouling in the corners of the grooves. In other words, it was a solution to a black powder problem, and one wonders why it was chosen for the Lee-Metford in 1889. The answer may be, at least partially, that in the previous couple of years major military powers had been very much concerned to keep up in the arms race resulting from the introduction of smokeless powders, and the British made their choice without sufficient long-term experience of the effects of cordite as a propellant. Doubly surprising, therefore, that this rifling was also chosen by the Japanese some years later.

The answer to the problems arising from shooting lead bullets in a bore profile originally made for BP is, I suggest, to reduce both bullet hardness and velocity to BP levels!

If I had the correct mould, I would cast bullets in a hardness of no more than 15 Brinell, well lubricated, and use a very moderate load of a fairly slow powder (N150, N160, H4831 or similar). Keep the muzzle velocity down to no more than 450 meters/sec, and maybe experiment with a match-head sized blob of lubricant (hydraulic seal) between powder and bullet base!

I realize that this sounds completely different to what smokeless shooters are used to, but I would be very interested to hear the results of such a test.


Patrick

[gew1975]

I used that Lyman mold with wheel weights sized to .267 in front of 20 grains of Accurate 5744. My T38 shot 4 inches high at 50 yards but the group is inline and 1.5 in diameter. Do not use more powder and start with 15 grains and triple check this data for your own use.

[Bruce McAskill]

That information from gew1975 pretty much goes along with what Patrick was saying. The Accurate 5744 is a good smokeless powder replacement for Black powder. I know a lot of people have tried using lead in the T-38 rifles and none have had acceptable results including me. Might have to break out my T-38 carbine and try some 5744 in it.