What is your opinion of Marlin "Microgroove" rifling?

[Hokkmike]

Bought my first ever Marlin 882 SS WMR rifle. It is used but in very good condition. As I do with any "new" gun I wiped it down and ran a bore snake with Rem Oil down the barrel. It looks good. But instead of the larger, more obvious, and somewhat more spaced rifling lines I noticed closer and lighter concentric circles in the spiral of rifling. This is, apparently, the Marlin "Microgroove" system. The lines seem so light to me. Can anybody tell me how effective this kind of rifling is? All other factors being equal, what kind of accuracy can I expect? Thanks for your opinions.

 

[TurtlePhish]

I've got a Marlin 795 .22lr with the Microgroove rifling. It seems to be doing it's job, and admirably- it shoots around 1.5MOA with Federal bulk Automatch, out to around 75yds.

 

[greyling22]

you'll hear mixed reviews on it. marlin went to it to shoot jacketed bullets better, but later switched back to regular so it probably wasn't great experiment. I shoot lead in my 1894 357 with microgroove. It's reasonably accurate (I'm not a good shot, esp offhand with irons) does not lead any worse than my other 357's. But you probably won't be shooting lead so I wouldn't sweat it.

 

[RPRNY]

Micro-groove rifling is very effective and with jacketed or properly sized lead bullets will be as accurate as any traditionally cut or hammer forged barrel. Will the rifling foul quicker than deeper cut traditional rifling? Probably. Would I use a micro-groove rifle for my cast bullet mainstay? Maybe not. But this was pretty revolutionary technology in its day and while it helped Marlin bring down cost and tooling depletion, it has also proved to be very effective in stabilizing bullets.

 

[chicharrones]

My Marlin 39 has the microgroove rifling. The grooves apparently don't have to be so deep since the grooves are so numerous as to get a good enough "bite" on the bullet. I haven't had leading problems in my 39.

Is the Microgroove rifling as accurate as my traditionally rifled rimfires? I'd say it is equal to regular rifling in some of my guns but not up to par with one.

I'd take your new Marlin .22 Mag rifle out and see what ammo it likes. It might be more accurate than you expect it to be.

 

[Ehtereon11B]

I have the micro rifling in my 336 .35Rem. Cleaning it is a little different since copper and carbon have smaller places to hide so I spend a few extra minutes on the barrel to get it clean. It is however very accurate with FTX bullets, haven't tried jacketed in it though. Haven't had a reason to yet.

 

[sandmatt]

Try some Winchester Supreme 34 grain JHP in that Marlin, it is spendy but shoots better than anything else in my Marlin 882 by a considerable margin.

 

[planetmobius]

I think you will be fine with the 22 WMR. Everything is jacketed and microgroove does well with jackets. I have a colection of Marlins but I sought out the older vitage ones with the Ballard style rifling. I never had much luck with the microgroove and center fire rifles. Some were OK but some I couldn't keep on a standard issue pie plate at 100 yards. I had an 1894 in 44 mag that was especially bad.

The big problem comes with cast bullets. I have heard that it works with slightly oversized cast bulets. But who wants to mess with that for each and every rifle. Good riddence to microgroove.

 

[FiveInADime]

All of the rimfire Marlins I have ever encountered were amazingly accurate. I have some reservations about the centerfires with microgrooves, but both of my .22LR Marlins have shot many .25'' groups at 50 yards. Most reports on the .22WMR Marlins are good. I have shot a 917M2 that put up nickel-sized groups at 100 yards with no wind.

 

[Sheepdog1968]

I have a 336 in 30-30 with microgroove. Almost exclusively shoot leverevoluition (soft polymer tip with copper jacket and lead core). I once got 8 out of 10 shots to group somewhere between 1 and 1.5" at 100 yards which is better than I normally shoot. I clean it about every 200 to 500 rounds. I've never used a copper cleaner, just bronze brush and CLP. I've been happy with the microgroove based on the group sizes I normally obtain and the every now and then group sizes I obtain when I shoot above average.

 

[RPRNY]

This article on the history and technology of micro-groove rifling may be of some interest.

http://www.leverguns.com/articles/fryxell/microgrove-barrels.htm

 

[average_shooter]

I shoot lead a great deal more than jacketed bullets through my 1894C with micro-groove rifling, frequently BP cartridge loads, and have had quite decent accuracy and never noticed any leading or over-fouling problems. Aside from the notorious (and notoriously easy to fix) "Marlin Jam" the rifle has proven to be a great addition to the collection.

 

[Temp430]

I bought my kid a Marlin 60 that shoots dime sized groups at 60 yds with CCI Mini Mags. I sighted in at 60 yards since that is where it's Leupold rimfire scope is parallax free. Not bad for a $150 rifle.

 

[Dr.Rob]

I have .22 cal microgroove rifles around here that are older than me that still shoot like new.

Nothing at all wrong with the barrels.

The 882 trigger isn't especially good.

 

[Hokkmike]

Thanks very much for the article on the microgroove process....

 

[jeepnik]

Microgroove is groovy man!

Seriously, it's fine. There's the urban legend that it doesn't stabilize cast bullets very well, but it's just that, a legend. A "properly" sized cast bullet (to get the proper size, you should slug "your" barrel) will work just fine.