JB bore paste diagnoses

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VectorMan
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Re: JB bore paste diagnoses

Post by VectorMan »

semtav wrote: Sun Feb 10, 2019 2:18 pm
BFD wrote: Sun Feb 10, 2019 9:52 amnope
Dang now you got me to thinking maybe it's that rubber washer you been pushing down that hot barrel all the time. Hope not !!
I was wondering the same thing. I don’t like putting soft rubber down a hot barrel. I know the barrel gets really hot when shooting in 100 degree weather. My barrel has been too hot to hold on to.
"keep adding powder til it bloodies your nose and blacks your eyes, then back it off bout 5 grains."
VectorMan
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Re: JB bore paste diagnoses

Post by VectorMan »

kenny s wrote: Sun Feb 10, 2019 1:43 pm 'hey Honey. go for a long run and catch this!"

only legal in Arkansas and certain parts of W. Virginia

apologies to all you Ark and W. V guys....Ken
?
"keep adding powder til it bloodies your nose and blacks your eyes, then back it off bout 5 grains."
BFD
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Re: JB bore paste diagnoses

Post by BFD »

Brian, relax. I've been pushing rubber washers for 25+ yrs now. For 24+ of them, there was no problem. It is not the washers (I usually triple patch for Target rifle and that hasn't helped in the slightest).
BFD
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Re: JB bore paste diagnoses

Post by BFD »

VectorMan wrote: Sun Feb 10, 2019 2:24 pm
semtav wrote: Sun Feb 10, 2019 2:18 pm
BFD wrote: Sun Feb 10, 2019 9:52 amnope
Dang now you got me to thinking maybe it's that rubber washer you been pushing down that hot barrel all the time. Hope not !!
I was wondering the same thing. I don’t like putting soft rubber down a hot barrel. I know the barrel gets really hot when shooting in 100 degree weather. My barrel has been too hot to hold on to.
Your barrels does not get really hot. It doesn't boil water, so it's not higher than 212F and that's not even close to melting that rubber. Not to mention if the washers were melting, they wouldn't work after 1 or 2 passes, and mine tend to work for years. That's hundreds of shots per washer.
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bpcr shooter
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Re: JB bore paste diagnoses

Post by bpcr shooter »

If you would like, I can meet you at Lodi and we could do some testing??? Im at a loss for whats wrong, but if you need a place to shoot.....I can arrange that for you.... just let me know!!! Matt
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BFD
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Re: JB bore paste diagnoses

Post by BFD »

Matt, I really appreciate the offer, but right now, I don't know what to even try. It is an interesting conundrum, but a very discouraging one. I will be trying a different source of lead, but that's all I have left to play with. I will start with the muzzleloader at Oak Ridge in March and see where that takes me.
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bpcr shooter
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Re: JB bore paste diagnoses

Post by bpcr shooter »

your bullets are the same weight as they were before correct??? If so I wouldn't suspect a alloy change. Tin is lighter as well with antimony, so the addition or subtraction of either would result in different weights, and if you doubled your tin by accident at 760deg your bullets will frost really bad dont ask me how I know :D. I would look at brass maybe a good anneal?? , primers, same lot of powder??,

Primer.....same lot you have been using??
powder....." "
brass....... annealing procedure the same??
paper.....same
compression.....

Do you have any old bullets laying around??? so you can compare old/new bullets for hardness. Just thinking out loud.....
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BFD
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Re: JB bore paste diagnoses

Post by BFD »

Primer - same case of 10,000

Powder batch changed at approximately (maybe exactly) the time that accuracy went out the window. However, switching to a different batch of powder did not seem to help. More powder batch experimentation is in order.

Annealing unlikely. The muzzleloader (.45 long range rifle) was also affected. It uses the same powder, same charge and same bullet as the BPCR rifle.

Paper. Same.

Compression slightly more because the newer batch is slightly less dense. Difference is very small however. Muzzleloader doesn't use compression in that way.

So, powder is still in the running, but something Kirk said has me thinking about lead a bit. Yes, the bullets weigh the same as they always did, but antimony in small amounts can have big hardness effects and thus relatively little or no impact on weight (at least in comparison with what tin can do.
Kurt suggested that my new source of tin, new roofing lead scraps from Phoenix, could have some arsenic in it. So my bullets could, indeed, be harder and I not realize it. My old lead was pure virgin lead from the DOE Run Smelter in Missouri before it closed.

My accuracy problems have been similar to what happened back in the old days when my bullets were too soft and slumping. So, I have tried harder bullets 12:1 I think. Maybe it was just 14:1. I don't recall exactly right now. But in any event, it did not help. Now Kurt has me wondering if maybe it was actually the wrong direction. Maybe the bullets with the new lead are too hard and not bumping up enough. There was, occasionally, a little bit of lead. In the muzzleloader, sometimes a lot of lead, which I wrote off to stripping a patch somehow, maybe on loading. But maybe it is gas cutting. So for the last 24 hrs, I'm thinking softer, not harder.

I am waiting for a mythical blizzard so I can have enough snow to shoot. But that's not happening. The latest Snopocalyps just fizzled into a nice little 4" dusting. But I'm thinking 18:1 is the way to go suddenly. Need to check my notes for leading in the cartridge rifles, but I know the muzzleloader had it.

Stay tuned for the next sequel.
mdeland
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Re: JB bore paste diagnoses

Post by mdeland »

Looks like you have tried just about everything but bore agitation by hand lapping or fire lapping !
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Lumpy Grits
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Re: JB bore paste diagnoses

Post by Lumpy Grits »

My bet-it's the lead alloy. :wink:
Gary
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