Micro Grooves

[m24]

Was reading up on Micro Grooves. Came upon this article.

In their 1954 catalog, they outlined numerous advantages that this new form of rifling had, including better accuracy, ease of cleaning, elimination of gas leakage, higher velocities and lower chamber pressures. They also mentioned "...a bore of greater than standard size..." in their discussion of how Microgroove rifling did not engrave (distort) a bullet jacket as deeply as conventional rifling.

1) It seems like it was first a cost cutting feature in production- with added benefits. Now question is why isn't it the norm rather than the exception?
2) how do the mechanics of getting higher velocities with smaller charges work?
3) And what about Barrel life - with much shallower grooves?
4) Has anybody tried the KF ammo on a rifle with micro grooves in them? Has anybody tried the chrony /accuracy/ penetration comparision test on regular and micro grooves rifle??

Regards

[PRITAM PATEL]

Hi,
I m familiar with term micro grove, cos my uncle has 39A marlin .22 lever action rifle since long back,

as quoted by Marlin the rifle has 24" heavy barrel with 16 micro groves,by inspection groves seems actually shallower than many imported .177 airguns

and I m witness of more than 30k shots been through the same rifle, some times ago i tried to check barrel with live ammo, bullet faced down to muzzle end, i could hardly push the bullet up to its first gas band on standard KF .22 LR round,

in short it seemed to me pretty tight compare to many foreign .22 rifle's barrels,

how does it shoots, pretty close groups on paper and I can regularly able to hit empty beer bottles neck at approx 150 feet with help of 6 x 32 mini bug buster from leapers. and could break tea cups at 200 feet distance regularly

i cant comment on velocity gain( no chroney) but it easily digests long barrel cleaning intervals (i.e 200, 250 shots)

rest you have to feel by actually shooting by your self

please note, the rifle belonged to a retired Police officer ( today's IG rank) who had taken countless wild boars, Chittals , Sambhars (in his time ) with the same rifle before my uncle bought from his son somewhere around 1985. I guess that answers penetration and effectiveness quarry

regards
pritam

[shooter]

countless wild boars, Chittals , Sambhars (in his time )

A .22 that can take a sambar or a wild boar is surely a keeper.

[MoA]

Micro grooves are popular... however the rimfire BR crowd are leaning towards two groove barrels.

[PRITAM PATEL]

countless wild boars, Chittals , Sambhars (in his time )

A .22 that can take a sambar or a wild boar is surely a keeper.

indeed it is a keeper

Thats the reason 39a is the oldest design still in production, ( lots of goodies like simple design, easy to dis-assemble, clean , 24" of heavy barrel with overall length of approx 36" ,about 3 kg in wt & 19 LR shot capacity )

even I m looking one for myself to replace IOF .22

regards

[captrakshitsharma]

well i can't claim the authenticity but a family friend claims his uncle used to take down leopards with well placed shots using his BSA .22 . however i would not tease a leopard and risk being mauled if in todays times game was still legal.

[Amit357]

Hi guys the 22 LR is one of the most underrated cartridge in India,i have seen Axix deer stoned with a proper placement shot with a 22,have seen wild boars fall with a 22,something that can knock down a wild boar would easily take down a leopard,wont recommend it,but can be done,SHOT PLACEMENT,PRACTICE,PRACTICE { guess if the H'able Home Minister has his way wont be able to practice } as KARMOJA BELL said "10 GRAINS IN THE RIGHT PLACE IS MUCH BETTER THAN A WHOLE LOT MORE IN THE WRONG ONE"

[dev]

My marlin groups half inch at fifty meters with kf's with a scope and a bench. Its trigger is a pain in the #ss though and its tiring to shoot a tighter group. Heartbeat goes crazy after twenty controlled breathing shots. Groups could be tighter with a slightly improved trigger.
So most Marlins will shoot pretty well due to the micro-groove we checked a few shots with KF's over the chrony, they were doing 1000 to 1100fps if memory serves me right.