Tell Micro Groove from Ballard

[C-dubb]

Going to start looking for a good used lever action (probably a Marlin) and I have never seen a Micro Groove barrel.
Since I would rather not have one, I thought it would be nice if I knew how to spot one.
What do they look like inside ?, and are there any markings on the gun that would tell me what kind of rifling that particular Marlin has ?

[rking22]

Its going to have 16 or so grooves vs the 5 or 6 in a "normal" barrel. Look down the bore of any marlin 22 you can pick up and you will see what is described. I am not a Marlin owner, but do some reading ON THIS FORUM before going with the common thought that a micrgroove won't work.
Also read the stickies in the leverguns subforum, below.

[C-dubb]

will do and thanks, that helps a lot.

[MyFlatline]

Micro groove will shoot cast just fine. As stated will have more grooves and they will be shallower and it's stamped on the barrel

[RED BEAR]

i have a 444 marlin with micro grove barrel and it shoots the lee 310 grain just fine.

[MyFlatline]

i have a 444 marlin with micro grove barrel and it shoots the lee 310 grain just fine.

This is the best I can get with the 250, what is your 310 load as I have some..?

[ElCheapo]

Nothing wrong with a microgroove barrel! Back when it was legal to do so I killed everything around here with my 357 mag Marlin lever gun and hard cast WFN bullets. It still shoots better than I do!

[dale2242]

Not to hijack this thread but why is regular rifling called "Ballard" ?

[truckjohn]

Marlin did extensive testing and found that their microgroove rifling patterns were consistently more accurate than anything else on the market at the time.

That's a pretty darned impressive claim when you have a chance to shoot Marlin Ballard cut barrels from the same era.

[Hickory]

Marlin did extensive testing and found that their microgroove rifling patterns were consistently more accurate than anything else on the market at the time.

That's a pretty darned impressive claim when you have a chance to shoot Marlin Ballard cut barrels from the same era.

The results of those tests were with jacketed bullets not cast.

[richhodg66]

Marlin did extensive testing and found that their microgroove rifling patterns were consistently more accurate than anything else on the market at the time.

That's a pretty darned impressive claim when you have a chance to shoot Marlin Ballard cut barrels from the same era.

I'd heard that they went to the Micro Groove because it was cheaper to produce. Never owned a Micro Groove one, so can't say, but it seems if they were that much better, every other manufacturer would have copied it like the Savage Accu Trigger.

[Texas by God]

All I know about Microgroove Marlins is that with jacketed bullets they will out shoot the Winchester most every time.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[uscra112]

Ballard rifling got the nickname because the last of the Marlin-built Ballard rifles had deeper grooves, at a time when most makers of target barrels used shallow grooves which were better for paper-patched bullets . Ballard went to deeper grooves to support the newfangled concept of "naked" bullets with lube grooves. This was in the 1880s, mind you, and everything was black powder. That's the legend anyway. Since Marlin owned the Ballard name, no other gunmaker ever used the term. Marlin surely used it for marketing, trading on the sterling reputation of Ballard rifles had made in Schuetzen competition.

Microgroove barrels have been used successfully for modern day cast bullet target shooting.

My later model Microgroove Marlin 336 .30-30 has 12 grooves, and they are as deep as Ballard rifling, and the grooves and lands are almost equal width. My older .35 Rem 336 has 16 shallow grooves and the lands are quite narrow. It nonetheless shoots properly sized bullets with a full diameter nose section just as well as jacketed. (Bore-rider noses that work for wide lands don't work at all well in Microgrooves.)

I think the only reason that Marlin changed was the mountains of bull published saying that Microgroove wouldn't shoot cast, written by people too ignorant to do the job right.

My memory may fail me, but I believe the Microgroove barrels were broached. A very quick method of rifling a barrel, but broaches are very expensive, and very hard to maintain. Outpost75 will correct me if I'm wrong.

[Norske]

My Marlin 1894 44 magnum has Ballard rifling, but it's not very deep compared to my Ruger Super Blackhawks. The most accurate load I've yet found is the up[dated version of Ol' Elmer's powder charge of now 20 gr of Alliant 2400 with a jacketed bullet. Cast bullets, whether mine or purchased, only work well with lesser velocities.

[uscra112]

I've run gas-checked linotype 200 grain bullets to 2000 fps. in my .35 Rem. If you're having trouble, you're doing it wrong.

[osteodoc08]

I think you’ve been given guidance on how to determine the difference.

Whether you choose to seek out a non microgroove barrel is up to you. All of my marlins have shot just fine.

[john.k]

Microgrooved rifling is button formed........read the patent.......the patent also claims that by profiling the outside of the tube,the rifling formed is tapered ,less deep at the muzzle end...........and idea which has always been associated with accuracy in lead bullet guns...........the Ballard tag was dreamed up by ad men,as a counter to criticism that m/g barrels couldnt use cast..............which we all know isnt true.

[yeahbub]

Micro-groove rifling is button rifled, has 12-16 lands and grooves, the number of which varied depending on the favor/disfavor showed by the shooting public at various times in their history. I don't recall what year it was, but the change from 16 grooves to 12 was made after sufficient complaints that cast boolit accuracy was hard to achieve with the 16's, even though people who understood the necessary details of shooting cast boolits knew how to do it. I suspect by then there was a newer generation of shooters/hunters not as familiar with the knowledge, intricacies and attention to detail needed to produce the desired results with cast. It's not that MG rifling doesn't work, rather, some detail as-yet unknown to the shooter is amiss. A common mistake is sizing them the same diameter one uses for conventional barrels. In my experience, this doesn't work well. With cast shooting, boolit fit is king and the bore/groove is commonly a touch larger than in barrels by other makers. For instance, with 12 grooves, the rifling need only be half as deep as with 6 to spin a given boolit. A recent measurement on a .30-30 micro-groove barrel showed the bore to be .3025 rather than .300, thus bore-riding designs with a nose of .300 will not ride on and be guided by the lands. The groove diameter in this one is .308 on the money, so a cast boolit of .310-.311 would be a good place to start, preferably woth a fat bore-riding nose. In my case, my molds don't cast oversize enough (.002-.004") for the over-large groove diameter in mine, so I paper-patch and size to the desired diameter and they do fine, not to mention the advantage of eliminating any lead-to-steel contact for a fouling-free barrel all day long, but not everyone wants to paper patch.

[woody1]

read this


http://www.lasc.us/fryxellmarlin-microgroove.htm

[truckjohn]

The other question - simply how to tell.....

Look down the barrel. If you count 4 lands and 4 grooves in a Marlin - it's conventional rifling. If it's 12 or more - it's Marlin microgroove. Simple as this.

On the design and why didn't others get in on the act? It was patented so nobody else could without paying for licensing.

But - most manufacturers did in fact change their rifling to a shallower rifling with smaller lands. Back in the day - lands and grooves were approximately the same width. Now - the lands are much narrower and grooves are much wider. Look at old rifle barrels from the 1940's and compare them to those of today. The rifling looks GIANT in comparison... Even 1940's Marlin 336 and even pre-microgroove Marlin 39a's and 99's - these 22lr barrels have huge rifling compared to what we are used to now...