Micro-Groove vs Ballard Rifling

[jakes10mm]

Is there any real performance difference between the Micro-Groove and Ballard rifling?  I'm looking for a Marlin 45-70 and found one of the older models with Micro-Groove riifling.  I recall reading something several years ago that claimed that the Micro-Groove was better for small bore (22LR) cartridges than big bores.  I also recall something to the effect of the Micro-Groove being more effective with cast/lead bullets than jacketed ones.  Any and all clarifications to help my "poor memory recall" will be greatly appreciated.

[dubber123]

Well, I actually heard that the micro-groove wasn't good with lead, only jacketed.  The most recent opinion is that you have to try it and see.  I guess some micro-groove barrels shoot lead well, some don't.  If you only intend on shooting jacketed, this doesn't matter at all.  I hope this helps, but bet it only confuses you more!.  I do know from personal experience that the Ballard style seems to shoot both bullet types well.

[jgalar]

My only Marlin with microgroove is a 30-30. All I shoot is home cast bullets. It is very accurate and gives no problems. From my experience the microgroove shoots lead bullets as well as any other rifling.

[GSaltzman]

It has been said that micro groove barrels will not shoot well with cast bullets. It is definately not true. I have found that my 1895ss will shoot cast bullets very accurately as long as they are heavy bullets. I have seen this happen in three different rifles. I have tried 300 grain cast with terrible results. Stepped it up to 385-420 grains and what a difference. My rifle will shoot 1" groups at 100 yards. I have used IMR 3031 and H322 for max loads.

[Mikey]

If you have a micro groove barrel and want to shoot cast then go to the Beartooth Bullets website (add a www and a.com) to get the truth about using cast bullets in the micro groove barrels.  I have had a number of micro-groove barrels and have had wonderful success and incredible accuracy with heavy hardhitting cast loads.  

Do not believe any hype about micro-grooves not shooting cast slugs well.  It is just hype.  Micro-grooves will shoot cast slugs very well and possibly better than jacketed.  Get on over to that website and read what has been written (and tested in micro-groove barrels), it will amaze you.  Mikey.

[GSaltzman]

One other thing to add. Veral Smith talks about micro groove barrels in his cast bullet book. Anyone who either cast or just shoots cast bullets should have this book. He knows what he's talking about!

[apollo]

I had a 336 CS 30/30 with micro-groove that shot it's best groups with cast. I also have a 336 in 35 rem. that shoots cast bullets just as good as jacketed. I have a 1895 45/70 that used to be micro-grrove and it shot cast extremely well but I thought that I would go ahead and get a ballard rifled barrel so I did. It still shoots cast very accurately but not any better than the micro-groove barrel that used to be on it. The key to cast bullets and micro-groove is the bullet must not be undersized and it needs to be a fairly hard alloy. I have found that a #2 alloy works well and straight wheel weight bullets that are heat treated also work extremely well.