Micro groove Marlin Barrel history question

[JFrank]

I picked up this 30-30 Marlin the other day cause I always wanted one, Blah Blah , anyway I have no idea what the Benefits if any towards this micro groove barrel. I’ believe it’s a 1-10 twist rate but any information would be much appreciated.

 

[earlthegoat2]

The benefits are less cost to produce for Marlin back in the day.

The disadvantages are often hyped but have very little real world merit.

Basically, it is a solid rifle whether it has MG or Ballard or whatever else Marlin may have used.

 

[DocRock]

ETG nailed it in one.

The uninitiated are prone to suggest that MG barrels do not shoot cast bullets well. This is false. Your barrel should shoot .310 cast bullets of BHN 10 - 15 very well at speeds of up to 1800 fps. It is true that above 1800 fps, MG barrels may not be best for cast. It is indeed a 1:10 twist barrel. Great rifle. Enjoy!

 

[3Crows]

Marlin started doing the Micro Groove rifling some time around 1954 I think it was or there about. There is nothing wrong with Micro Groove barrels and they are very accurate. I do not shoot cast bullets in my 30-30 Marlins so that controversy matters not to me. All of my Micro Groove Marlin 30-30s like the Sierra 170 grain bullet in home loads and do very well with the Hornady FTX 160 grain factory stuff. I have also found that new Federal Hammer Down 150 grain stuff to shoot well. Why not you ask, well, I feel I give up too much with cast bullets, around 600+ FPS or more and little or no expansion compared to a quality jacketed hunting bullet meant for 30-30. I do use exclusively cast lead bullets in my Marlin 45-70 as there I feel just the opposite, the 45-70 is not about velocity but mass instead and it already makes a huge hole so does not need much expansion.

 

[JFrank]

Wow
Great information guy’s I took a look at
some 150 gr Winchester sp over the weekend I wasn’t super impressed with 2 inch group at 100 yards but hey that’s all there was at the LGS .

They all were kill shots so there’s that part just not small

 

[Obturation]

Wow
Great information guy’s I took a look at
some 150 gr Winchester sp over the weekend I wasn’t super impressed with 2 inch group at 100 yards but hey that’s all there was at the LGS .

They all were kill shots so there’s that part just not small

2" @ 100 yards with a 336 is pretty normal, some do a little better and many do worse. Find a load it likes and go with it.

 

[rdnktrkr]

My SILs Marlin really likes 170gr bullets over 3031 powder, he can steady ring 4" steel at 200yrds not so with the factory 150gr he bought for the brass.

 

[3Crows]

I wasn’t super impressed with 2 inch group at 100 yards but hey that’s all there was at the LGS .

My REP 336SS will shoot sub MOA for about three consecutive shots from cold before shot number 4 goes out a little and then number 5 a little farther. If I switch to another rifle and allow it to cool down it repeats. This is from a bench/bags with a Leupold 1.5X4 scope. If you insist on lever guns with no scope and must use the iron sights then good luck with that if trying to shoot MOA.



And my JM Texan with Winchester 170 grain, steel El Paso Weaver 3X:



Shot for shot, with any ammo, the REP rifle beats the JM rifle but when the old Texan has a good day, it has a good day .

Lever guns are not target rifles, they are hunting tools and I would say if you can get consistent sub 2 inch groups at 100 yards you are golden for deer to 250 yards.

Why are lever guns not a bench rest target rifle, well, the magazine tube pulls on the barrel, there are barrel clamps or end clamps pulling and pushing a wooden fore stock tightly to the barrel. As the barrel heats and grows, the other parts do not thus slightly changing the POI. One day, I will do an experiment and pull the fore stock and barrel bands and magazine tube from the rifles and single feed rounds and see what they will do.

 

[PapaG]

My mid-50s MG Marlin shoots 1 1/2" five shot 100 yard groups with Rem 170 and 3" with 150s. Cast bullets soon. Just got a hundred pounds of lead alloyed and ready to go. Starting at .309 and can go to .311 with dies I have. Got great results with cast in my pre-64 M70 30-06 and a 788 Rem 308.