Marlin 336 throat dimensions for 30-30

[oldsagerat]

Does anybody have the accurate throat dimensions, length and diameter, that Marlin uses for
30-30 chambers?

[Pepe Ray]

Ranch Dog, Michael Reamy of Texas, was a prolific member here. He developed the RD line of molds, each designed to fit the Marlin chambers.
He favored Marlins and found ,as you have, that boolets which worked in Winchester chambers were NOT ideal for Marlins.
Somewhere in these tomes you'll find detailed drawings of Marlin chambers and the RD boolets which made them "SHINE".
Pepe Ray

[JWFilips]

I can pipe in saying the original Ranch Dog Lee mould 30-30 boolits fit the early Marlin 336's Once the Marlins became Remlins then I think NOE adapted the RD boolit to suit the new chambers.
Somewhere in the recent archives RD himself explained this

[JWFilips]

Found it:Posted by Ranch Dog
See below I quote:
Greetings fellows, the big difference in to two is the bore riding nose of the later version.




Prior to 2010, Marlin's had a lot of slop in them. Some of that slop was the large chamber throat. There might be several theories about why they cut it but I believe it was to resolve chambering issues associated with lever action feed. The original bullet simply plugged the oversized hole.


Around 2010, the period that the serial number appeared on the side of the receiver, Marlins started to tighten up. My personal view is that this happened with Marlin's association with Hornady and that outfit's desire to send a pointy bullet out of the Marlin barrel. The chambers started to tighten up (and the feed issues started to increase).


This really whacked Remington in the **** as they believed they could CNC a rifle around a spec drawing and put it together. You can get it together but then the darn thing won't feed, which they found out. Slowly they learned how much slop to cut in the action to get the cartridge from the tube to the chamber but they kept a SAAMI spec chamber. Mossberg and Rossi do the same thing.


Back to my two bullets. If you have a Mossberg, Remlin, or Rossi; the latter version of my bullet is best for you. If you have a "JM" Marlin with the serial number on the side of the receiver, the same thing, I would use the latter version with the bore rider nose.


In order to get the original bullet to feed in these rifles, you are going to end up sizing the bullet down to get it to reliably feed into the chamber because the huge throat in the chamber is not there. You can size that original down but you start to cut the bullet down at the ogive. I also do not like sizing down the Micro Bands, I like keep that as close to design as possible, because the start to disappear with sizing. In theory, I can produce a clean drawing of a TLC-311-165-RF, either version, and show that it can be reduced to .309" and still have bands left for lube. In reality, as the bullet passed through a sizing die, excess alloy through shaving or compression, moves to the Micro Bands and you are left with little area for your lube. This leads me to state if your particular needs requires any of my designs to be sided down greater that .0015", choose NOE's standard lube groove versions.


The Winchesters have a fairly large throat but it leads down to a SAAMI spec bore quickly. My dad shoots it in is M94 but it has to be sized to .310" to get an effective OAL.


So back to the the question of which 30 caliber bullet to use in your 30-30 Win rifle:


The original TLC311-165-RF, use with:

"JM" Marlins that don't have the serial number on the side of the receivers.


The revised TLC311-165-RF with the bore rider nose:

"JM" Marlins that have the serial number on the side of the receiver.
Mossbergs
Rossi Rio Grandes
Winchester M94


In the applications use the bullet as cast or sized to .311". Size it down to .310 only if you have issues with chambering. Using these recommendations will eliminate 99% of the issues surrounding which bullet to shoot. These are outstanding bullets, I have seen them take hundreds of animals, deer and hogs, on my ranch.

[RickinTN]

There are great differences in Marlin 30-30 chambers in models from 1948 production until 1980 that I can attest to. Out of at least seven different 336's I have exactly ONE that will chamber the 165gr Ranch Dog bullet with it seated anywhere near the crimp groove. I have a 70's Winchester 94 that it works well in, so go figure.
My point is that not all 336 chambers are the same, and what mine is probably won't have a lot to do with what yours is. All of mine will chamber a .311" bullet and some larger. The throat length can vary between .085" and .250" or even more and until you measure yours it's anyone's guess what it measures.
Hope I've helped,
Rick

[geargnasher]

I've tried the NOE RD 165 bullet in nine different .30-30 chambers, including two marlin MG guns, three Winchester post-64 M94s, two Savage 219s, a Contender, and a Savage 99. The only one it fit and crimped in the groove was a 1966 336 Texan which has been firelapped, and it shot EXTREMELY well in that one. A 2001 336 that had seen only a few cast loads when I bought it has a super-tight throat and almost chokes on .301" bore riders. IOW, it's all over the map. You can trim the brass to suit your particular rifle's preferred depth with the NOE mould. I also tend to think the NOE moulds cast a bit fatter than the RD moulds cut by Lee.

Gear

[oldsagerat]

So, it appears that Marlin has had a variety of chamber dimensions over the years. I have consistently heard that
the weak point of Marlins was the micro-groove rifling. Sounds like the chamber dimensions, primarily the
throat is the primary source of inaccuracy and bullets key holing at 50 yards. Does that sound reasonable?

[RickinTN]

The throat shouldn't have an effect on bullets keyholing. From my experience keyholing bullets are usually from a bullet too long for the twist of the barrel to stabilize. All of the 336 Marlin rifles that I am familiar with have a twist rate of 1-10" so too long a bullet to stabilize is probably not the issue. Could the barrel be so leaded as to not allow the rifling to get a good purchase on the bullet in your rifle? That is the scenario which comes to mind. If I were to have to design a generic Marlin 336 bullet for the 30-30 it would have to be a bullet of about .311" diameter with a .085" driving band in front of the crimp groove and a bore-ride nose of .301" or maybe a .302" nose. A bullet of such description may not be the "best" bullet in any given rifle but should work reasonably well in most.
Good Luck,
Rick

PS Generally speaking a "micro-groove" barrel will tend to like a bullet a little harder than a typical ballard rifled barrel.

[geargnasher]

I think the MG rifling got a bad rap from cast bullet shooters because of myths propagated by our friends at Lyman who didn't have a decent bullet to shoot in them. The bores run around .303" and no "bore rider" will shoot very well in them once pressures start to get to the point that the nose fit and shape matter.

Gear

[oldsagerat]

So, does anyone make a barrel for the Marlins that is optimum for cast bullets? I like to carry a Marlin and now have to use rounds with less recoil than 30-06. So a Marlin in 30-30 would fill the bill. I have acquired a CZ-527 in
7.62x39 as a substitute for a Marlin as a carry rifle. Less than 6 pounds, 18.5 inch barrel and good iron sights.
Maybe I will also try a Marlin again. Is there year of Marlin that would be best?

[RickinTN]

If you are looking for a new purchase and want to avoid Micro-groove Marlin started the Micro-groove production in about 1955 if I remember correctly. From '48 until sometime in '55 they were ballard rifling and most shoot cast well. Rifles produced in '48 have an "E" serial number prefix and progress as "F"= 1949, "G"= 1950, "H"= 1951, "J"=1952, "K"= 1953 "L"= 1954.
I hope this helps,
Rick

[bones37]

There are great differences in Marlin 30-30 chambers in models from 1948 production until 1980 that I can attest to. Out of at least seven different 336's I have exactly ONE that will chamber the 165gr Ranch Dog bullet with it seated anywhere near the crimp groove. I have a 70's Winchester 94 that it works well in, so go figure.My point is that not all 336 chambers are the same, and what mine is probably won't have a lot to do with what yours is. All of mine will chamber a .311" bullet and some larger. The throat length can vary between .085" and .250" or even more and until you measure yours it's anyone's guess what it measures.Hope I've helped,RickIn my experience with a model 30AS(economy version of 336) which was made circa 1992, Rick and Gear are correct about their advice. My rifle would NOT chamber the NOE 311-165 RF as it choked on the bore ride section of the nose, however in my late 60's winchester '94 and a bolt action Savage(Revelation325) the boolit chambered and shot very well. FWIW, I size to .311 and all 3 rifles chamber this diameter. My Marlin 30AS has a throat of 0.115" and the riflings start abruptly with a .301" bore.bones37.

[icelander]

I have a 2014 336xlr with the 1 in 12" Ballard rifling and presumably the newer tighter throat. Which bullet is likely to work the best?