twidpa,
Hmmm...... The only reason that I can think of for groups upening up after several shots would be bore fouling / leading.
Do you know what your groove diameter is? If the bullets are smaller, gas cutting could be the problem.
I would suggest going with .454+ diameter bullets of at least 12 BHN hardness.
Because the Hornady is a soft bullet, the diameter decreases somewhat when seated in the case.

Personally I would not use a fast burning powder with the 335 LBT. My choice would be 20/2400 or 20/296 or 22/4227.

Juddy,
Would not the 45 Colt be considered a classic cartridge?

w30wcf

G'Day w30wcf
Here in Aus we have a Lever action discipline. It is shot on paper and as far as I know there are postal competitions against some other countries. One match is Classic Calibre and the cartridge had to be produced prior to 1938. The rules are here http://www.ssaa.org.au/competition-info ... lebook.pdf Have a look and you might want to have a go. The Classic Calibre Match is shot on contour targets. A overveiw of the discipline is here http://www.ssaa.org.au/competition-info ... action.pdf

Juddy

Juddy,
Thank you for the information. Now that is pretty NEAT!
If I lived in AUS, I would definitely join you fellows.

Thank you again,
w30wcf

w30wcf wrote:twidpa,
Hmmm...... The only reason that I can think of for groups upening up after several shots would be bore fouling / leading.
Do you know what your groove diameter is? If the bullets are smaller, gas cutting could be the problem.
I would suggest going with .454+ diameter bullets of at least 12 BHN hardness.
Because the Hornady is a soft bullet, the diameter decreases somewhat when seated in the case.

Personally I would not use a fast burning powder with the 335 LBT. My choice would be 20/2400 or 20/296 or 22/4227.

w30wcf

The 335 bullet was gas check and all bullets are at least .001 over and some were .004 over sized. I did try 21/ 296 and 21/4227 with same results. I experienced the same opening of the group also with jacketed bullets. I gave up and boxed it up and sent it off to Winchester. Maybe they can help.
Thanks.
T

My reply may not be relevent for the orignal poster. But, I have found that speeding up 45 LC did not improve the accuracy at all. As a matter of fact slowing down the velocity improved tremendously the accruacy of the gun. We use 16 grains of 2400 with a hornaday 250 grain jacketed bullet. It shoot really well, PC or CF.