Marlin 44mag throat slugged

[bmortell]

In my quest for accuracy previously i slugged the muzzle end and got .4315 so i lapped my sizer to .4325 and used that, i was getting 4 or 5 moa but i was using irons so i was happy didnt think it was the guns fault. Then recently i put my best leupold on it with good rings tightened everything properly ect. And still shot same size goups. So i thought id measure my throat because everyone says size for the throat for cast not the grove dia. So i did a pound cast in the throat area and uh, i dont have one.
257292
The groves of the rifling at the begining of the bore measure .4325 then it just angles up to the chamber size in one go. So what should i do just up the sizer to .433 or .4335 ? Why does it not have a throat

[Hickory]

Marlin 44 magnum barrels have many short comings.

[dkf]

Maybe you want to pick up the NOE push through die body and a .433" and .434" sized bushings to try instead of keep lapping out your sizer.

[Outpost75]

If you have your Marlin barrel re-throated to have a cylindrical ball seat of .432" diameter ahead of the case mouth for a distance of about 0.060-0.080," then reduce the angle of the origin of rifling to a six degree included angle, you will easily cut your group size in half.

[trapper9260]

I size my Marlin 44mag boolits to .431 from .430 and my groups close up some. Better then it was. My groups are about less then 2" at 50 yards.

[waco]

https://www.youtube.com/watch?v=dq1_8qxHj2c&t=103s
https://www.youtube.com/watch?v=cm4JmLFdmAI
I found boolit diameter makes ALL the difference. Marlins have large throats as it is. Keep trying bigger until groups shrink.
My Marlin 1894 Cowboy in .357 Mag likes a .361" boolit. Check it out.

[onelight]

https://www.youtube.com/watch?v=dq1_8qxHj2c&t=103s
https://www.youtube.com/watch?v=cm4JmLFdmAI
I found boolit diameter makes ALL the difference. Marlins have large throats as it is. Keep trying bigger until groups shrink.
My Marlin 1894 Cowboy in .357 Mag likes a .361" boolit. Check it out.
Uh , did you look at his cast in post 1

[DougGuy]

If you can take the bolt out of it and gain a straight shot at the barrel you could rent a piloted reamer from 4D Rentals and throat it yourself. Manson reamers generally have a 1.5 degree leade on the rifling so you have a 3 degree included angle and this works great. I would suggest a longer freebore, up to .200" before the leade ins start, this allows the boolit to exit the case mouth and stabilize in the throat, the freebore holds it square in the bore and concentric to the bore, you can't hurt a pistol caliber barrel with the longer throat, groups will shrink accordingly IF you can size to the throat.

[waco]

Uh , did you look at his cast in post 1

Yup. No throat Marlins are nothing new. Size as big that can still chamber and odds are you'll find the best accuracy... easy...

[kungfustyle]

Marlin isn't the only one. My Rossi is the same way. This will save a great deal of frustration: https://www.titanreloading.com/lee-precision-reloading-equipment/lee-pistol-reloading-dies/lee-collet-style-crimp-dies/lee-44-magnum-collet-style-crimp-die it's a collet crimp die. I had to get an NOE mold and size my boolit to .433 with a custom size die from buffalo https://www.buffaloarms.com/ I used a 45 acp seating die and my 44 reloading die to crimp till I got the collet crimp die. Why sammi specs are different for rifles blows my mind.

[bmortell]

i don't wanna ream myself a throat or whatever, that's more than im comfortable with. and don't have gunsmith around or money for them, so the gun is staying how it is. for sizing i can up the size of my push through just fine, i already upped it twice so i have no problem doing it again. but what exactly is a collet crimp die? if i recall it puts more of a bottleneck looking crimp on, when i adjust crimp down on my regular die it makes a bottleneck look. how is it different or better? maybe i should try heavy crimping cause i been doing light crimp since i thought it didn't really need it since its not a revolver. guess ill try .433 with heavy crimp next test

[onelight]

i don't wanna ream myself a throat or whatever, that's more than im comfortable with. and don't have gunsmith around or money for them, so the gun is staying how it is. for sizing i can up the size of my push through just fine, i already upped it twice so i have no problem doing it again. but what exactly is a collet crimp die? if i recall it puts more of a bottleneck looking crimp on, when i adjust crimp down on my regular die it makes a bottleneck look. how is it different or better? maybe i should try heavy crimping cause i been doing light crimp since i thought it didn't really need it since its not a revolver. guess ill try .433 with heavy crimp next test

To each his own , but in a tubular magazine you have the spring and the weight of the other rounds trying to push the bullet back in the case under recoil and when it feeds all slam back on the round behind .So I like a good crimp in lever guns.

[475BH]

If your casting and your bullets drop over .433, itll be good.
I dont think a heavy crimp would get you any where.
Id like to be corrected, but as in t/c contender barrels. Use the largest bullet that will chamber, and start your accuracy trials from there.

[bmortell]

my mold is .432 then I powder coat so I can atleast size to .433 and get smooth full contact maybe .4335. if not do 2 coats and get the next size range. so my projectiles and sizer can grow as needed. maybe I can do some sort of test to figure out the largest size that will still chamber fine without upping my sizer to do it. I could probably bump a boolits diameter with a press, mic it, seat it, chamber it and repeat until I find that size. then I would have a known window to test in between there and where im at now. sorry just thinking out loud.

[35remington]

I have struggled with poorly throated rifles and cast bullets before,. Often no amount of change in sizing or bullet seating depth adjustment improved accuracy. The reason is the throat, and if that happens to you the throat must be addressed if you want lead bullets to shoot well.

No choice.

[fcvan]

Wow, I didn’t know the Marlin 44 was such a pain. Is that since the merger or before even. I bought a marlin in 41 mag over 30 years ago, and I didn’t have these kinds of issues. Maybe it is just the 44, but another person above said his 357 Had the same problem. I will look forward to the information from anyone who has knowledge. I also hope the OP sorts out his issues.

[35remington]

Well before. A rifle having a throat ill suited for cast bullet use is not at all uncommon. This is not just a Marlin problem. Most ever shoot anything but jacketed bullets anyway so the problem occurs for only some users. Jacketed bullets are often more tolerant of this sort of thing in that they will at least shoot acceptably.

[bmortell]

actually I tried 180gr factory ammo jhp and they shot even worse, I haven't had 240gr to try though since im mostly cast only these days. ill work on diameter stuff I mentioned one of these days but I still wanna hear from people on what collet crimp is cause ive heard a few times people saying different kinds of crimps made them more accurate but ive only ever had standard roll crimp die

[35remington]

Having tried and used both kinds of crimps I am extremely skeptical as to their value as an accuracy aid given what else is going on.

[35remington]

My luck with jacketed bullets having short bearing surfaces in Marlin barrels has not been promising.

[mdi]

I had a few problems with my Puma in 44 Mag. until I re-slugged the barrel. Since SAAMI groove dimensions are different for a rifle (.431" vs .429" for handguns) all my cast bullets were a bit small at .431"-.432" for the .432" barrel so I just opened up a Lee sizer to .433" (+ a hair). I now use Ranch Dog bullets sized to .433" and they work fine. I didn't do a chamber cast but all my cast bullets in mixed brass will chamber fine.

[trapper9260]

Marlin 44 is not bad like some are saying. My works good for me and it was made in 1980 and got it used. As for my RH I shoot .431 in it also like I do with my Marlin ,but needed to use different loads for each.

[44magLeo]

I have a Marlin in 44 mag I bought new in 1978. With the 429421 I shoot as cast, lube with LLA, No sizing. It shoots well that way.
I got a RD 265 gr RFN, NOE's version. I have cast a few but haven't shot any yet. I'll start as cast. If they chamber that way I'll shoot them that way.
On a fired case measure the ID of the case mouth. Size your bullets to that size. Size your cases, expander with an expander .002 under your bullet size. NOE makes two sizes of expanders. I have both. The .434x.430 is in the pistol group. The .436x.432 is in the rifle group.
I have other expanders that expand to .427, .428, .429. These just flare the case mouth after that.
One is from a Lyman 310 set it has the .428 with the M step to .430. So I can expand cases to 5 different sizes. I think I can find one that works.
I do have a Lee push through sizer that I honed out. It is about .4335 If I decide to try sizing my bullets.
Leo