Help with 247 whisper bullet and barrel leading? Need a place to start....

[BK7saum]

I recently started casting the 247 whisper bullet. I have been hand loading for 25 years with J-words and the occasional cast boolits. But am basically a noob when it comes to the serious casting and loading.

I was wanting an alloy to open up or mushroom at subsonic velocity and decided to try 3:1 Pb to COWW with 1% tin. The allow cast fairly well but is obviously soft, maybe too soft for my purposes. ( I understand I might need to smelt a new alloy at 50/50 or 2:1 ).

Another possible problem I have is the Lee sizing die (.309 nominal). With this soft alloy, the bullet is being sized .3084-.3085. One question, will a harder alloy size larger. I'm about ready to polish the ID and open it up to .309 or .3095. BTW my barrel slugged out right at .308 for groove diameter.

I may have shot myself in the foot(figuratively, of course) in that I didn't clean the bore. I just wanted to verify if the bullets would stabilize and ended up with serious leading. The leading was prevalent in the first 8-10" of the 16" rifle barrel.

The rifle is a 16" 300 whisper with a 8 twist shilen barrel.

Oh, I am using the 45/45/10 recluse tumble lube.

I was also using two fast pistol powders, American Select and also Unique. The loads, around 6-6.5 grains gave velocities in the 950 to 1025 range. (I realize that a slower powder might/should work better with a softer allow, and that is something I plan on doing if I stick with this allow. I currently have 25 pounds mixed up). My understanding is that the slower powder (I have 1680 on hand) will give a slower push to the bullet and might allow it to engage the rifling without skidding and subsequent leading.

SO.....I have several things going on

1: A fouled bore, powder and copper jacket fouling.
2: A soft allow (can scratch with a thumbnail)
3: A fast twist rifling
4: Possibly undersized bullets for my application
5: A fast powder with a rapid peak pressure, possibly causing bullets to skid.

The testing
The first shot was stable and left a round hole (15') (I didn't check the barrel for leading and believe that the barrel leaded with the first shot)
The second and third shots keyholed (I checked for leading and found significant leading in the breech half of the barrel)
The fourth and fifth shots (with gas checks) were stable and left a round hole (15'). I was trying to cut some of the leading out with the checks, but it was a nogo. There was still signifcant leading in the barrel.



I do appreciate any insite from the wealth of knowledge on this board. I have identified places to start. The barrel has been scrubbed and is clean.



Should my first step be to retry this allow sized to the .3084" diameter, gas checked (or unchecked), with Recluse lube and see if it works without leading (in a clean bore)

Or should I use a new 50:50 allow and start fresh?

Do I need to open up the ID of the die to .309"+ before sizing any more boolits and testing?

I know I have a lot of questions. I am only trying to learn and hope to not have to make all the mistakes myself. Thanks for you patience and any wisdom, suggestions, and ideas.

Brad

I have read A LOT on this forum over the last few months/year, and know that some (probably all) of this has been covered here and there. I have read threads over alloy, bullet size to bore diameter, lubing, powder choice, etc, and don't think I've missed too many of them. However, I hate cleaning a leaded barrel, especially a rifle barrel, and any help that gets me to a good, workable load that doesn't lead sooner rather than later saves me from cleaning and recleaning a leaded barrel. Thanks, again.

[Moonie]

What is your intended use for the boolits? I cast this boolit using water dropped WW alloy and shoot unsized and ungas checked in 2 AR uppers. I do use slower powders than you are but I have not had any leading issues at all, but then my uppers have never had jacketed bullets in them to have to clean out first.

[Elkins45]

I have had my best results with the heavy Lee in my BLK by tumbling in 45/45/10 and shooting unsized. I'll bet fit is your problem.

Slower powders have been dramatically more accurate with plain based boolets.

[BK7saum]

My intended use is hogs and deer.

Unsized is too large for chamber. I think I'll go ahead and polish out the lee die to give me. 001-.002" over groove diameter.

[Jailer]

You shouldn't need to water drop those at the velocities you will be pushing them. I would try sizing to .310 and see how that does.

All of my 30 cal rifles will lead with anything sized smaller than .310

[Moonie]

Why are you wanting to shoot them at subsonic velocities? I can understand if you are supressing them however I shoot these boolits at closer to 1,500fps for hunting, at that velocity straight WW metal expands quite well.

[popper]

Harder alloy will size a tad larger. You might get the .310 sizer to try the softer alloy, save the .309 for the harder(you can't make em smaller). The .310 works for my AR carbine with ~50/50 alloy without leading, slugged @ .308. I'd cast some with harder alloy first, .310 actual size. Make a comparison of results. Take a bore brush with chore-boy with you to push out any leading. I've not noticed the copper/lead problem but I guess it does exist. I'd thought of trying Unique or 2400 but don't think it will cycle.

[BK7saum]

I plan to shoot them suppressed through my bolt action.

Thanks for the suggestions. I now have some cast with 50/50 with 1% tin. I haven't sized them yet to see final sized dimension.

[popper]

I had similar results with Unique and unchecked CB in my 30-30. Gas cut city. You do test without the can, right?

[blikseme300]

Slower powders have been dramatically more accurate with plain based boolets.

My experience has been the same even when GC is used. Went to H335 from Lil Gun in my blackout and accuracy is now as good.


Bliksem
Sent from my iPad using Tapatalk

[BK7saum]

Thanks bliksem.

I was thinking that 1680 would give a more gradual start to the boolit.

I'll try both alloys with 1680 and see how they shoot.

[BK7saum]

Popper,

Yes, I do test without the can. I can only imagine the baffle strikes I would have had if the bullet was sideways at 10-15'.

[BK7saum]

I sized 4 rounds with gas check and shot them with aa1680. There was no apparent leading and all 4 printed round holes on paper. Bullets were 50-50. Looks like this might work.

Brad.