TLC311-165RF Surprise

[Rooster59]

Just recently got around to casting up some bullets with my new TLC311-165RF mold. It works great dropping bullets at around .312-.313". Ran a few through the sizer to .311" and checked them, then loaded them in some resized brass to check for chamber OAL.

To my surprise they make contact at a very short 2.385"! Wondering if I should forge ahead at that OAL to work up my loads or consider doing something about the short throat.

[62chevy]

Is this a dummy round you are working with or is it loaded.

[Rooster59]

LOL. Oh heck no they aren't loaded! Just sized brass and the checked bullet. No primer live or dead.

Actually, after I messed with them more it looks like they will have to be seated around 2.375" to stay off the lands. Maybe a little longer but I quit messing with them today.

[mr surveyor]

Rooster .... the gun your trying that boolit in wouldn't happen to be a '84 336TS, would it?



jd

[Ranch Dog]

As I recall Rooster, you have the original TLC311-165-RF?

It works great dropping bullets at around .312-.313".

That is a bit on the high side as it should be a .311 bullet out of the mold but you did not mention the alloy you used. Of course, bigger is better than smaller to a certain point.

Ran a few through the sizer to .311" and checked them, then loaded them in some resized brass to check for chamber OAL. To my surprise they make contact at a very short 2.385"! Wondering if I should forge ahead at that OAL to work up my loads or consider doing something about the short throat.

This bullet was originally designed for the 1950 era Marlin's, running into the '60s when Marlin was cutting a very large throat in their rifles. Marlin never explained the throat but it was probably to aid cartridge feed and help reduce the amount of time required to "fit" a Marlin prior to shipping it. As their manufacturing improved the rifles tightened up (I use the side safety as the point where the "fit" was refined), so did their throats on the rifles and the ogive on a cast bullet doesn't need to radius into such a large base to fill it. By the time Marlin was in bed with Remington, the throats really got tight and they moved to a CNC built rifle. Of course, this is what ate Remington's lunch it that they had no experience with leverguns. They were dumbfounded that you could not cut a a CNC rifle, assembly it and have it work. You can't even guess some engineering slop into the build. A levergun must be hand finished. Okay, I've left the topic…

My guess is you have a fairly modern Marlin, pardon please if you've told me in the past, as there is just too much going on in my gray matter. I would immediately guess it is not a "beaver tail" forearm rifle or it would have swallowed the bullet. So, yes this bullet will need to have the brass trimmed to match the crimp groove. You can increase the OAL some by sizing the bullet to .310", that is why I offered this sizer when I had a online store, but in that you're bullet dropped as large as .313" you want to be careful about not destroying the Micro-Bands.

You didn't mention your alloy, the mold cavities where designed for Lyman #2. I found that the best alloy for Micro-Band definition. If you move your alloy to a mix on the pure lead side of the Lyman, bullet diameter will decrease but you might loose a little definition with the bands (bullet weight will also increase).

Two weeks ago, I had to load some ammunition for my Dad's Glenfield 30GT; with the bullet sized to .310 it needs the brass trimmed to 1.975" for a cartridge OAL of 2.430". I needed to start a new "lot" of brass for this project so I tried to get my Dad to move to my "B" bullet, the newer version of this design were I was only concerned with the fit of the more modern Marlins, but he didn't want anything changed. I only have one other 30-30 Win now, a Rossi Rio Grande. With this "B" bullet I trim the brass to 2.025" and use an OAL of 2.500"

[Ranch Dog]

The Similar Topics on the bottom of the page brought up your related topic so I see that your rifle is the later Glenfield. You would probably be best served with the bullet sized at .310" if the bullet was dropping closer to .311". As it is, size at .311.

In that post, we talked about the data. I never got around to revising anything, just to much going on in my life. In fact, at the end of the month that web page will be retired as well. It has been over two years since I closed the business and Lee has never made an attempt to market my designs so it is time for this effort to retire as well.

[Rooster59]

Rooster .... the gun your trying that boolit in wouldn't happen to be a '84 336TS, would it?



jd

How did you know? Precisely.

[Rooster59]

Actually, it is an '84 336TS. My wife's rifle is a '62 Texan that was 35Rem, and I purchased a NIB 336TS (84) barrel and installed it. So, the old rifle and "newer" rifle both have the safety era barrels.

The mold is your B design if I am interpreting the sketches properly. It has a driving band forward of the crimp groove/top lube groove.

The thing that puzzles me is that I am not having trouble with the driving band. The bullet nose makes contact with the rifling forward of the driving band. It is where your sketch (B mold) shows the bullet goes to .303". I haven't measured where the contact starts to the case flange/bolt face, but it looks like there is essentially no throat/leade in either barrel. I actually had to seat one bullet with the case (2.032") at the forward edge of the driving band to avoid any contact with the rifling. If I remember (I'm at work now) that resulted in a COAL of right at 2.370". At that length the bullet sticks into the case way below the shoulder.

[Ranch Dog]

Because of the barrel swap, is there a chance that the headspacing is incorrect?

[Rooster59]

I don't think so. I checked my rifle first then hers. They both are imprinting the bullet ogive at the same place. As best as I can tell with the naked eye and a caliper.

Her head space might be a touch loose as some factory Federal 150FN all show a little backing out of the primers but it only happens with that round. My handloads with Sierra 125HPFN don't exhibit that symptom.

Is there any reason I wouldn't want to have a qualified gunsmith ream the throats just a tad to emulate the looser Marlins?