30 30 marlin 336 cant seat the bullet correct????

I just got a lee 309 diameter170g #309-170f Double Cavity from Lee. I cast the bullets lubersized with gas check and tried to seat the bullets. It appears that when I am chambering the bullets they will not seat to the Leman specs which is 2.52. I can lower the bullet down to 2.33 and they chamber well. I guess my question is that the correct thing to do or is there something else that I am not thinking of. I am new reloading lead but i have reloaded 45 and 44 with no problems. The gun that I am using is the Marlin 336. I can get the 2.52 seated but I really have to press the bullet into the chamber and it leaves these grooves on the bullet if I extract the bullet with out shooting. I am going to see if I can post a picture. Thanks in advance to your responses.

Welcome to the Guide.

From your clear description it is obvious what the problem is. Every chambering reamer is a little different, and your chamber is a bit different from the one the specs you found were taken from. The marks on the bullet from the barrel's grooves clearly indicate the 2.52" COAL is too great for that bullet in your chamber. You did the correct thing to allieviate the problem: reducing COAL until they chambered easily and properly.

Just remember if you have a MicroGroove barrel that the size of your bullets is critical to good accuracy. MG barrels will not tolerate bullets of too small a diameter, and they often don't like them overly hard, either. (With a conventionally rifled barrel, you can sometimes get away with a bullet slightly undersized by using a softer alloy.) I have best luck with nothing harder than wheel weights (optimum for .30-30 hunting bullets anyway), and depending on what the barrel slugs, .310" or .311".

That Lee 170FN bullet and Lyman 311041 are my two of my favorite .30-30 bullets, along with the Lee 150FN and the 117"soupcan".

if they chamber and de-chamber i see no problem.
if i were using them for hunting where a second shot might be needed then i'd opt for the shorter round.
shoot it both ways and see which is more accurate then decide whats best for you.
i often target shoot by single loading each round.
but have an entirely different set-up and load for hunting.
using the same boolit and rifle.

In checking my Modern Reloading by Richard Lee, it recommends a max OAL of 2.480 for his 170 gr cast bullet.

Hope that helps.

There are a lot of published numbers that don't necessarily work out in the real world. Most data is generated using only one test rifle or a universal reciever with interchangable pressure barrels, the reason why the published velocity and pressure numbers don't always track closely with your guns when you test the same components. wmannix's rifle's chamber obviously has too tight a throat to go by Lee's numbers with this bullet, and his is most definitely not the only .30-30 chamber out there that way - I have had two, one was a Contender and the other is a Savage bolt. Both will chamber any factory rounds with slimmer ogive jacketed bullets, but they will not chamber Lee 309-170FN's at the recommended OAL. One would never suspect it until trying certain cast bullets. Similar problems are encountered with the almost non-existant throats of Swiss K-31's, the mil rounds for which were loaded with bullets that have a smaller diameter ogive than usual .30cal bullets with a bearing surface of the regular size, requiring that they be seated more deeply than one might prefer.

With some chambers, you can exceed recommended OAL by quite a bit without any problems and are limited only by what will fit and feed through the magazine if you want more than one single loaded shot. With others, maybe the chambering reamer was ground to slightly different specs, the throat was cut separately or incompletely (like a Swiss rifle), or the machinist was having a bad hair day and certain bullets need a shorter OAL to work in their chambers.

Handloading gives us the ability to be flexible and create cartridges designed for optimum use in individual firearms, within reasonable limits. Some supposedly standard chambers are so different from expected that we must in effect create wildcat ammo for them in order for it to feed/function correctly and give decent accuracy and case life. Two extreme examples of this are .303 SMLE's and 7.62x54R Moisin/Nagants whose chambers and bore diameters can vary so much it's hard to believe. Even modern production rifles all have a fair amount of variation, too, or you would be able to get away with neck sizing mixed brass fired in several different rifles of the same chambering without needing to segregate the cases for each rifle. I wish it worked that way. :)

i wish it worked that way too.
in the 7.65 argie there is definately a x53 and an x54 chambering.
i have three of these 2 of them i can interchange rounds bolts also and have no problems swapping ammo bolts fired rounds whatever between the two.
the third is not interchangeable in any way except it will fire the shorter rounds from the other two if desired.
but this over works the brass severely.
my two k-31's are basically interchangeable but with different degrees of accuracy.
also my two ruger 77-ii 's they will shoot the same rounds but with different depth seatings to the same exact load.
they need the bullets seated to different depths for best accuracy, actually hard to tell the difference between the groups unless you mix up the ammo.
with my two 7x57 ackleys cut with the same reamer [mine]by two different smiths you cannot
interchange rounds unless sized fully by the full length sizer.
so i tend to treat each gun as a wildcat no matter what, or full length size everything and take the losses in brass life and accuracy. [generic loading i call it]
even molds are not cut to the same specifications.
my 31's will shoot the 30-165-silhouette just fine cast from ww alloy others won't because of the nose size.
my 308 will shoot the same boolit but it fits better and is far more accurate when cast from a 4Sn 6Sb alloy.
same powder load and filler is used in both the 308 and 7.5. it's all in the bbl throat/groove dimensions.