43-287B

[Brad]

I hunk the biggest single factor is 432 throats and a 429 barrel. Those 3 thou of bullet have to go somewhere. It isn't just what is displaced by the rifling, there is .003 of bullet getting moved just because the groove diameter is smaller than the bullet.

If Ruger made revolvers with 429 or 430 throats this would be far easier.

I want to see how a 429 or 430 bullet does but I need to make a 429 sizer first.

I'm no engineer or math wizard but near as I can tell just the smaller bore to larger buller requires 2.6 gr of bullet to move somewhere.

 

[fiver]

2.6 gr is @ the lubes weight.

 

[Pistolero]

Just need a tiny hydraulic jack to push it into the throat.

Seriously, what about a LPmag primer and a no powder case to intentionally push
one into the bbl, but not out. May take .5 gr of TG or something. Stick one in the
bbl, then drive it back out.

Kids, don't try this at home, Brad is a professional.

Bill

 

[Ian]

I'm wondering about making the nose like a self-aligning rifle bullet....you know, the convex ogive, short semi-bore-riding section at bore diameter +.001", then a tapered shoulder leading up to the front band. Big crimp groove to tolerate displaced metal, then deep lube groove behind that.

 

[Pistolero]

I think you just invented 429421, Ian. Or maybe more like a
LBT, which eliminate's the shoulder of the SWC.

Bill

 

[Brad]

Just need a tiny hydraulic jack to push it into the throat.

Seriously, what about a LPmag primer and a no powder case to intentionally push
one into the bbl, but not out. May take .5 gr of TG or something. Stick one in the
bbl, then drive it back out.

Kids, don't try this at home, Brad is a professional.

Bill

I thought about 1/2 gr of TG! Like you said just enough to stick it in the barrel then drive it back out.
Maybe some time when the wife is away and I can head to the garage.

 

[Pistolero]

Make sure you have a good catcher ready in case it makes it out....

Crazy minds run down the same alleys, or something.

Bill

 

[Brad]

Firelapped my GP100 into a semi hard bucket of drywall mud at the old house. After over 100 rounds it barely cracked the bottom of the barrel.
I have a bucket and some sand that will work fine.

 

[Pistolero]

It will be interesting.

I really like the concept of lathe turning bullets until you find a design that works
well, then you can get a custom mold made.

Bill

 

[Pistolero]

It may also be interesting to note how far they go down the bbl. If the nose is having
real trouble moving metal, it seems like it shouldn't travel as far down the bbl. I
would think that farther travel would tend to be a good thing, meaning smooth, easy
transition to the bbl.

Bill

 

[358156 hp]

I thought about 1/2 gr of TG! Like you said just enough to stick it in the barrel then drive it back out.
Maybe some time when the wife is away and I can head to the garage.

If you try this, consider deep-seating the bullet in the case, sort of like a wadcutter, but perhaps a mite deeper. This could possibly raise the chamber pressure enough to push the bullet completely through the barrel. The only potential issue I see would be if the case sags a bit in the chamber. Since you "neck size" this might not be an issue for you. If 1/2 gr doesn't clear the muzzle, .75 gr might. You get the idea.

 

[Pistolero]

Trying to AVOID clearing the muzzle, he wants to stick it in the barrel.

Bill

 

[Brad]

What I would love to see is Tom and Dan step in and give some ideas on what they have seen work over the years. Somehow I think mould makers are likely also mould testers and tinkerers.

 

[fiver]

actually Ian just described why I prefer RNFP bullets.

 

[Rick]

Brad has posted some common sense logical ideas. Posted the groove and rifling dimensions, lathe cut the front band to a taper leaving enough full diameter front band to be in the throat when chambered. Will give the bullet a much easier ride into the rifling as opposed to the full diameter hitting Ruger's built in bore restriction.

 

[Brad]

Getting ready to head to the range. I have some loaded over 9 gr of Unique to see what lower pressure does to the bullets. Some have grooves on the nose and I hope to see how those look too.
I am also taking the Marlin. The loaded rounds just fit the chamber. The nose of firm on the lands. The rifle has microgoorve rifling with a fat bore. I use .433 bullets in the rifle. Will be interesting to see what those bullets look like after being squeeze down less. They also won't have the long jump to rifling.

 

[popper]

I use a washer to size the nose just enough so it puts ~0.1" into the lands but not jammed (Marlin 30/30). Groups shrank 50%.

 

[Brad]

Ever have a day when something hits you right upside the head? I did today.

A bunch of us have been wondering if the bullet was getting mangled because too much lead was moving around. I decided to test it today. The berms were not giving up bullets easily but I found a couple and holy cow do they tell a story.

Here is a bullet sized .432 coaster with Hi-Tek. Load was 9 gr of Unique which my Lyman manual lists as a starting load for a 275 gr cast. Supposed to be 23 KPSI but I think it is higher than that in this revolver.

You can see bits of the coating remain but not much. The lube groove shows the deformation we have come to know so well. You can also see a bit of lead on the left side of the check. That lead is always on the check above the groove that is smeared to the rear. This bulelt was fired from the SRH.




Here are two bullets loaded and cast identical to the above bullet. Only difference is that they were fired from my Marlin 1894 with microgroove rifling. The bore on this gun is larger, it prefers a .433 bullet. Notice a lack of lead on the check at all and the lube groove is neither collapsed totally or smeared on one side.

I believe this is good evidence that the .432 bullet hitting a .429 bore is getting smeared horribly. The fact it shoots as well at 100 as it does is amazing.


This is an NOE 503 sized .430 loaded over titegeoup. This is the preferred load for the 624. This was fired in the SRH. You can see where the bands collapsed a bit under the rifling but they had nice big grooves to flow into. The lube groove still exists as does the crimp groove. This is straight range scrap air cooled, likely BHn 11-12.

The SRH has a mismatch between cylinder throats and bore. The throats like a .432 bullet but the bore isn't a fan in some cases. I need to casts more of the 287B and cut some noses to see what can be done to help the situation. I also want to see if sizing the bullet .429 makes a difference. I need to make a .429 sizer to find out.

I only recovered a few of the bullets I hoped to today but they do tell a very interesting tale.

 

[fiver]

it's also interesting to note that the forward angled crimp groove allows the lands to flow the lead right into place without it pushing too much to the rear.
this is why I advocate lube groove walls to be cut on such a wide angle when you have a long drive band.

I asked you to shoot some in the marlin for just this reason.
it shows just about what I figured it would.

 

[Ian]

EXCELLENT!

You're right, the problem is obvious.

There's another rarely seen but extremely telling little point about the coated one recovered from the SRH: Notice the land engrave is wider on the bullet than on the gas check???? That means ABRASION from the leading edge of the land. If it weren't for the check, those would have leaded horribly and been lucky to hit the berm. This tells me you need more tin with that load, or maybe just bullet lube would take care of it. In any event, the alloy and coating are not working with that Unique load at all.

I wonder how soft your bore slug was, Brad? I'm skeptical that the groove is only .429", I would expect .427" measured in a vee block, if it was pure, dead-soft lead. What the revolver is doing to those bullets is well beyond .003" of sizing down. OR, maybe it's just the really tight .414" bore and wide lands killing the bullets?