Tumbling 155 gr SWC

[Glenn H]

So today was IPSC.  I had a batch of 155 SWC lead over HS-6 (9.9 gr).  Not nearly as accurate as I'd like, in fact some of the targets showed evidence of keyholing indicating that the round was tumbling.  I haven't chronoed this round but the guestimate is it should be moving around 1175-1200 fps.

No real evidence of leading in the barrel.

Any suggestions other than shoot up what I have?

I used to use 175 SWC and have a batch of 180 RNL loaded up.  The 180 seems to run pretty well.

I also have a question, I know that 1.260 is the max case length, how far, generally speaking, below the 1.260 do you seat the bullets in your loads?  Do you run right at 1.260 or pull back to 1.250 or even less?

THANKS

[sqlbullet]

I am curious to see what the solution to your keyholing is.  I would not think they are being overdriven at that speed.

In response to the COL question....My 1911's won't eat a SWC seated longer than 1.250".  So, I run them 1.245".

[The_Shadow]

You may want to slow them down a little to se if things improve.  Also don't over crimp them or if you are using a factory crimp die be careful that you are not squeezing the bullets too much.  Most all of my 10mm rounds are set to 1.250" or less.

The 200 grain XTP's I load to 1.260" if testing the upper end of performance then reduce to 1.250" test again if the loads prove OK!

[Glenn H]

Thanks for the replies.  I think I'll reseat them just a schosch down, maybe to 1.250 and see what happens.  I am not forcing the crimp so I don't think I'm overcrimping.

[The_Shadow]

How is the diameter?  And what make pistol are you shooting them out of...Glock polygonal?  Standard Rifling? 

Longer bullet do stabilize better than the shorter ones, but undersize really don't grab the rifling and may just not stabilize correctly.

[Yondering]

I had a batch of 155 SWC lead over HS-6 (9.9 gr).  Not nearly as accurate as I'd like, in fact some of the targets showed evidence of keyholing indicating that the round was tumbling.

Are these a soft bullet, or some sort of hard cast? If they are too soft, and/or undersized for your barrel, they may be stripping in the rifling, especially if you're using the stock Glock barrel. My Glock barrels like harder alloys for this reason.

Did you cast these yourself, or are they commercial bullets?

If you're using a Lee factory crimp die, remove it from your loading sequence when loading cast bullets. They are no good for cast!

[sqlbullet]

If you're using a Lee factory crimp die, remove it from your loading sequence when loading cast bullets. They are no good for cast!

This is very good advice.  A bullet that fits properly when cast/sized may be undersize by the time it reaches the rifling due to an aggressive crimp.

[Yondering]

If you're using a Lee factory crimp die, remove it from your loading sequence when loading cast bullets. They are no good for cast!

This is very good advice.  A bullet that fits properly when cast/sized may be undersize by the time it reaches the rifling due to an aggressive crimp.

It's not the crimp that's the problem with that die; the Lee Factory Crimp dies in most pistol calibers have a carbide sizing ring that's supposed to iron out imperfections. The problem is that they size down that slightly oversized (compared to jacketed) cast bullet, often making it too small for the bore.

Some people have had success cutting off the lower portion of the die that holds the carbide ring.

The rifle caliber Factory Crimp dies are a completely different design, with no sizer ring.

[The_Shadow]

Youndering, you're absolutely correct about the LEE FCD, it can squeeze the bullets down too much using it to iron out the casing as a finishing crimp.  I wouldn't cut off the carbide sizing ring, I only use mine for the "pass thru" feature for restoring the cases from stem to stern!

One other thing is case neck expansion, very critical to eliminate bullet shaving but still maintain proper neck tension.

[sqlbullet]

Agreed about the carbide ring, although I have read reports that later dies don't have this issue as badly.

And, while I do use a Lee FCD with cast bullets in 30-06, 308 and 300 win mag, I have also had occasional issues if I really crank it with my 308 die.  Don't have the issue with the 30-06 or the 300 Win Mag.

[Glenn H]

Hi, shooting a 1006 so pretty standard.  I've never seen this happen before.  I'm using an RCBS die set.  The bullets are commercial (Colorado Bullet Company) but they recently changed ownership and don't carry this particular bullet any more.

I don't know what the hardness is but they seem to be pretty close to what I've shot before.