How do I avoid leading my barrel?

[alamo5000]

I just watched a video about slugging the barrel. I will give it a go.

[dellet]

Not that difficult as you saw. I use 32 caliber round balls, that are .310” and pure lead. Also have been known just to shoot the bullet I’m using into a 55 gallon barrel of water or start it down the barrel with an empty case and the bullet just pushed by a primer. Then pushed through with a dowel.

Have used lead spilt shot fishing sinkers when you stil get them.

Recovering a shot bullet would tell you a lot about what might be going on.and you might be worrying about a lot of things that aren’t really happening. Would be the first time someone bought a bullet that just did not shot worth spit in their barrel.

Hornady round ball.
https://www.midwayusa.com/product/11651 ... round-ball

[Boolit_Head]

You can find fishing weights that are about the right size and they are soft lead. That makes it easier to drive through the barrel.

[alamo5000]

Also have been known just to shoot the bullet I’m using into a 55 gallon barrel of water

I could shoot one like this I am pretty sure. Won't the bullet break up or whatever? I think this way, just simply shooting the bullet would tell me everything and then some and I could even try 4 or 5 different things to see if it makes a difference. IE powder, seating depth etc.

[alamo5000]

On a mere chance I found this too... it's the actual chamber specs for 300 BLK that Ballistic Advantage uses. Take a look and see if you guys can find anything.

https://ballisticadvantage.com/blog/wp- ... hamber.pdf

[dellet]

Here's a bullet fired into and recovered from water jugs. You could get groove and land diameters as well as see that it was not sealing the bore




The chamber print looks fine, as long as the actual chamber looks the same.

The critical spot is the transition form the end of the neck at 1.378" to the lead at 1.391". Note the reamer print defines that angle as 45 degrees.

There should also be a taper at the throat where it tapers from .309" to 300". if eother of those places have a step instead of a taper it could be trouble.


Since your bullet is .3085 the first, most likely spot, does not really come into play.

[popper]

I push a PCd 145gr plain base to 2100 in the BO. I tried uncoated base for a while, got the AGB stuck but only problem, cutting at the pistol port. Using H110. That is not your problem. I do coat the base now. Loading short and bullet slightly off center may cause a smidge to get knocked of at the bore, check run-out by standing on base in a row and look for nose out-of-line.. You do need to check your case OAL, too short can cause a problem (with soft alloy) but too long is really bad. My alloy is pretty much in the high 20s BHN.
That dwg shows a pretty good freebore in front of the neck but it is tapered? Much longer than SAAMI. Try cooking some bullets (HiTek) @ 400F, 1 hr, drop immediately in ice water. If they don't give you the ring, alloy is too soft. MBC uses 92/6/2 alloy, hardball, but may not be hard enough. Re-cooking and quenching will raise the hardness. Doesn't hurt the coating but it may get darker.

[alamo5000]

I have been laying off of the cast bullets for a while so this thread has gone kind of quiet. In the mean time I did some loads with 180 gr, 190gr, and 225gr jacketed bullets. All reliably subsonic

I 'think' I have the cast bullet thing down now to about 7.2 to 7.3 grains of IMR 4227. Somewhere in that neighborhood. I also had to play around with my gas block some to get some other powders to function the rifle.

Now that I 'think' I have a fairly reliable load, I can load up say 50 rounds and chrono the heck out of them and take a much larger sample size to see the velocity variations.

My question is, if my barrel will still get leaded in the chamber, about how many rounds in will I be able to see it? 30? 50? 100?

Depending on the answer this will determine how many rounds I load up. I will also do accuracy testing with various loads in the realm of my general area and see where to settle from there.

While I am on this I want to do enough of an endurance test to see if the problem is still present or not.