Plain base 30-30 woes

[fecmech]

I’m having problems in my Savage 340 30-30 rifle with plain based bullet #311041. I had a machinist friend PB my 2 cav mold with a .3105 dowel pin reamer. I’m loading in the 1200 fps range with 8.5 grs of Herco as my base load(works great with GC bullets). After PB’ing the mold I get throat leading in the first ½” of rifling(sizing .311”). I tried changing lubes and used simple lube,Cred,Beta(soap lube),and Javelina with no joy. Did an impact casting and determined I had a .309 groove, and 3098-.310 throat. Beagled the mold and sized .313, again no joy. Bullet mic’d .313 X .311. Took the mold back to my friend and we opened the base to .314 (O drill) and bullets drop with .314 base to first lube groove and .311 after that. Sizing to .313 as that’s the biggest I have and tried 2400 (11 grs) and WSF (8 grs) along with the Herco and still leads the throat after 3-4 rds. These loads should be roughly 20-25KPSI according to Lyman and about 1200 fps. Both the 2400 and Herco will shoot well for about 5 rds til the throat leads than it all goes south. Bullets have been cast initially with WW+ 2% sn,also tried 30/1(to try bumping up with Red Dot) and 50/50 WW/lino. No difference with any of the alloys, sizing or lubes. I tried 2 other bullets that drop .314, the Lee AK 150 gr bullet and a Lyman Loverin sized .313 without GC’s and got no throat leading at all (they didn’t shoot very well though). Those are the 2 bullets on the left, my 311041is the one on the right. What am I missing here guys?

[geargnasher]

Blowby in the throat. It's still happening even after you enlarged the base. I had fits with that in several of my .30-30s trying similar stuff to what you're doing (my pet load ended up using Longshot for about 1300 fps with a 311041).

My solution was to make paper gas checks out of manilla envelopes by stamping discs, spraying with Elmer's spray adhesive, sticking the boolits in the center and running through a base-first sizer. Got excellent accuracy, mirror bore, and zero leading up to 1700 fps using 2400 while testing the effectiveness of the checks. The paper check stops the blowby until the boolit can get engraved and cork the bore nicely.

Something else that worked but had its own issues was using dead-soft lead such that it would bump up in the throat. Another trick, and one you might consider as well, is using Dacron to take up the space between powder and body/shoulder junction, then trickling in some BPI Original shot buffer to about halfway up the neck and seating to crimp in the crimp groove. Filling the case with buffer would cause too much pressure, so I used the Dacron to take up the space and just put enough buffer behind the boolit to make a good seal. Anything you can do to prevent gas leaking around the boolit before it gets fully engraved will halt the throat leading. No lube in the universe will prevent it.

Gear

[fecmech]

Blowby in the throat.
Pretty much what I figured. I was hoping to avoid checks or fillers of any kind to make sizing quick and easy and just load these on my turret with the Lee collet neck sizer like pistol rounds. I may PB the Lee AK bullet and see how it works out as it does not lead without the check and shoots great with the check.

[44man]

Ever consider the check stopped skid but the lead is too soft with a PB?
Filler can act to block gas from skid marks but it is just a stop gap, so to say.

[geargnasher]

"Shouldn't", but it is. Which is happening first in this study: Neck expansion or boolit movement? If the boolits were skidding they would lead the whole way to the muzzle. In my rifles the lead caked pretty heavily in the first 1-2 inches of the bore past the throat after the first shot. The paper check solved the issue completely.

Gear

[fecmech]

Question: have you pulled a boolit that you've seated and then measured it again? If you have too much neck tension, the case may be sizing your boolit down below throat diameter.
Yes I have pulled a bullet and am using a Lyman M die plug of .310 dia. The bullets are not sizing down. I don't think it's bullet skid as I water dropped the beagled bullets and the latest try was the 50/50 WW/lino mix. These are only 1200 fps loads.

I don't understand the blow by either, bullets are seated with the front drive band into the rifling. If I extract a loaded round the rifling marks are about halfway into the first drive band.

[Doc Highwall]

What size is the case neck expander that you are using? Maybe your bullets are getting sized down when you are seating them.

[geargnasher]

Here's a link to the paper check thread that I hijacked from Brstevens. Pic on post 22. I checked my notes, I was getting right at 1700 fps with 2400 powder using water-quenched 50/50 alloy last summer, the last loads I messed with before settling back on the Longshot mousphart loads.

http://castboolits.gunloads.com/showthread.php?109049-Paper-Gas-Checks&highlight=manilla

Gear

[runfiverun]

it could be as simple as soft alloy riveting in the throat too.
you might could try a smaller boolit, or a hardened alloy.

[fecmech]

In that he didn't have leading with the Lee C312-155-2R or the Lyman 311407(?) without GCs, both sized .313" would leave me puzzled as well.
The only difference I can see is that both of those bullets the size of .313 extends further up the sides of the bullet . My 311041 is only .313 to the top of the base band, from there to the front drive band it's .311. I'm going to pick up a Lee 312-155-2R mold in the near future and PB it. Worst case scenario I'm out 20 bucks.
This whole fiasco started because I wanted a quick and easy way to shoot 30-30's at about 1200 fps with out a lot of effort. Run some PB bullets through my Star and load with the Lee collet neck sizer on my turret press. No fiddling with GC's, no case lube etc. Boy did that idea go south in a hurry!

[geargnasher]

The Speer 100 grain "plinker" half-jackets shoot nice.....

Your first sentence above, combined with the taper of the Lee boolit, should explain the lack of leading.

Gear

[Char-Gar]

Plain base joy = slow and soft.

It would seem you have the slow under control. How about the soft?

[geargnasher]

Further along Charle's line of reasoning, perhaps kick them with Trail Boss to help the bump?

Gear

[fecmech]

t would seem you have the slow under control. How about the soft?
I did try 30/1 with 7.0 Red Dot with the thought of bumping up the bullet but that was not successful. That was done with a .311 bullet before we enlarged the base and I scrounged up a .313 size die. I may revisit that with some 700x that I have. If the Lee bullet will shoot plain based I'll probably just sell the 311041.

[44man]

What is "bump?" I will never go with that. It is deformation and slump. Fit can not be improved. Some will consider pressure after skid with fast powders but it does not work, peak is gone, skid is already there so to "bump" after the boolit is down the bore is too late. Once gas channels open soft lead will not flow back into the channels. You have jets of hot gas eroding the channels larger. That gas pressure is extreme, 17,000 to 60,000 psi----have ANY IDEA HOW HIGH THAT IS?
The worst thing ever in print is light loads have no pressure but the truth is the pressure is high instantly. Once it is understood that the slower the pressure is applied, the softer the lead can be the better off you will be. You can't slam a putty ball.
The reason dead soft works with BP is the long, extended pressure rise that does not get near as high as smokeless even at peak.
Every single fast powder test I did showed the harder the boolit, the better and 231, Unique, etc was best at 28 to 30 BHN.
You need groove fit and anything over is a joke. Over throats in a revolver is a joke. The right boolit with the right powder can be groove size ONLY. .001" to .002" over does no harm but explain why it is needed!
I wish "bump" would go away, even a Minie' ball does not work without "fit."

[popper]

Get some powder coat & lacquer thinner, piglet coat the base(or all if you want). You make gruel consistency, dip the base in, cook for 20 min @ 450 or so. For what you want, possibly acrylic fingernail polish on the base band may work. I've even used polyurethane paint but it takes a long time to dry. The 100 gr plinker is fun, like a 22LR with a few grains of unique. I played with the RD180 in my 336 with unique & 2400, no leading (PCd) but no accuracy @ 16 gr. 19 gr of LeverE isn't a plinker load but almost feels like it. Accuracy is good & the extra 9 or so gr of powder doesn't cost much. Dacron filler helped a bit. You know it's a centerfire but it won't beat you up and is accurate. The same load with 4895 is just a tad less acurate and shoots the same.

[Freightman]

I agree with 44man bump up is a bad joke IMHO as I have dug out some of my boolits they could be reloaded except for the engraving where is the bump up? Popper has a good suggestion read the Pigglet powder coat thread and try it it works for me.

[marvelshooter]

"The reason dead soft works with BP is the long, extended pressure rise that does not get near as high as smokeless even at peak."
I was recently told during my quest to get a .38-55 to shoot that BP generated peak pressure at the moment of ignition and did indeed "bump up" an undersize boolit. BTW it did not work for me. I now patiently wait for someone more knowledgeable than I to clarify.

[fecmech]

You need groove fit and anything over is a joke.
Respectfully 44man I started this whole fiasco at .310 and went from there. I have had throat lead all the time with 311041. This was started as I said for a quick easy way to shoot a lot of 30-30 plinkers. I wanted to avoid GC's or any other special ministrations to the bullet,just cast, size, load and shoot. If the Lee 312-155 shoots accurately PB'd that will be it, if not I'm out $20. I have a couple of other bullets for the Savage that shoot great with GC's but if that's what it takes all the time I just won't shoot the Savage that much, I really don't like messing with GC's. I've got 3 lever guns in .357 that shoot PB bullets with very good accuracy so that's where I'll spend my time if I can't get this sorted out.

[TXGunNut]

If the Lee 312-155 shoots accurately PB'd that will be it, if not I'm out $20. -fecmech

Interesting thread, a 30-30 plinker load is getting close to the top of my project list.
If you've got another $20 take a look at the Lee TL314-90-SWC. I got it to dabble in 32-20 but it has possibilities for a 30-30 plinker as well. I haven't had a chance to try them but I gave some to my shooting buddy and his 30-30's like them, think he's using a little dab of 2400 for around 1200 fps. Decent accuracy at plinking distances from what we've seen so far.
I'd be happy to send you a handful, need to cast a few next session anyway.

[380AUTO]

Great info here keep it coming.

[leadman]

Your 50-50 WW lino alloy should be about 15 bhn air cooled and about 23 to 26bhn water quenched. At least that was my experience about 1 month ago testing the same alloy with the Hi-Tek coating. Or you could just use air cooled COWW.
Try air cooling some of your boolits and see what happens. Is still leading the easiest solution I can see without buying another mold is to put a pinch of dacron in the case. Once you become familar with using it one can pinch off a fairly consistent amount, close enough to not have to weigh it.