Marlin 336 engraving boolits

[FergusonTO35]

Hey folks. Spent some quality time with my Marlin 336 Texan and the Lee C309-150-RF. Sized to .310, this boolit shoots great over 28 grains IMR 4895. I do notice that my rifle apparently has a very short throat, there are quite noticeable rifling marks on the nose of the boolit after chambering it. Sometimes it makes the lever rather difficult to close.

As said before, the load shoots great and I'm not getting any pressure signs other than the occasional cracked neck (this brass has been loaded alot btw). Should I be concerned about it? Might it be prudent to have the throat opened up a little? Any Cast Boolits sponsors who do this?

[woody1]

IME, they all have pretty short throats, Not usually a problem. Personally I like to have the nose of the boolit engrave a little but I don't recall any engraving when I was shooting the Lee 150 rf but it's been a while. Unless you're really having a problem getting the bolt closed, certainly w/o excessive force, I wouldn't worry about it. What does the nose of your boolit measure? Regards, Woody

[FergusonTO35]

I'll measure some and let you know.

[dubber123]

If you are lubing in and in and out style lubrisizer, it is really easy to fatten the nose up with surprisingly little pressure, 2 fingers on the handle can do it to air cooled WW boolits. Almost .002" bigger. Took me a while to figure that one out. :)

[FergusonTO35]

Hmm, good idea. I've always been one of those who likes to really squash 'em when sizing.

[dubber123]

Hmm, good idea. I've always been one of those who likes to really squash 'em when sizing.

Me too, you'd be surprised how many molds aren't cut with bases perpendicular to the sides. This shows up on the bottom of plain based boolits really well when run through the sizer, the "ring" the center punch of the sizer die puts on the base won't be equal all the way around. Give them enough of a squish to square the base to the sides and watch your groups shrink ;)

I took to squashing the .30's I did a few weeks ago, and ran into nose issues on a Marlin 30-30. The nose started at .300+", and was .3015" after sizing. I had to go a lot gentler to prevent that. I am considering a push through size die, and then an oversize lube die to fill the lube grooves.

[jtaylor1960]

In my 32 Special rifles I trim the brass a little so I get enough engraving but not so much I might pull the bullets.That lets me use the crimp groove and lets the ammo function well.

[44man]

The nose on my Marlin boolits are .301" They barely touch the rifling. Then the bands are .311" and I made my boolit to just start to touch rifling, easy to chamber.
I made one mold with the nose too large so I size the nose only to .301". Lapped Lee die.
I would not fool with the chamber, make the boolit fit.
Now when I make my molds I put the blocks in my home made vise and the first cut is an end mill to make the tops perfect to the cherry. Just a skim cut. My bases are perfect 90° to the boolit.
One thing I found with the 30-30 was brass was not even and I had run out up to .022". A crooked start was all I had. I turned the necks just enough to even them, fire formed and now have 0 to .002" run out. Roll a round on a flat table and watch the boolit wobble, you waste time shooting them.178576178577 My boolit has done this at 100 yards. 3 shots in the can. The Marlin can shoot. 3031 and Varget, 4895 close behind, running around 1900 fps.