cast bullets in marlin microgroove

They should be just fine for cast bullets. The lands aren't as wide as those in pistols, but they are just as deep and there are many more of them. A Marlin chambered in 30-30 with a microgroove barrel does just fine with gas checked bullets so I don't see any reason why the 44 mag should be any different.

My M1 carbine, clone, has a microgroove bbl and shoots cast just fine as well.

bearhunter
 
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I use a 250gr SWGC and a 325gr Keith style SWGC in my 444 and it has microgroove rifling, no problems and I don't think you'll have any either. Cast bullets may be a little better suited to ballard rifling, but again, I haven't experienced any problems. Ideally, hard cast and sized about 0.001" over bore diameter has worked really well for me in that diameter of bullet.
 
Any reported problems generally revolve around leading, and accuracy. There are no safety issues with regard to the rifling.
Just go for it.
If you do have problems, I'm sure the Marlin cast shooters here can help.
 
Just don't try to shoot them to fast. My experience if shot over 1000 fps the fine rifling will crack at groove base. I found this out from bullets recovered from a hard snow drift
 
Have a micro-groove .444....As long as the cast bullets are .430-.431 diameter they are accurate and stay accurate to 2100 fps with a 315gr. from a NEI mold.
I get good accuracy....at 1450 fps with 315 cast in a 14 inch T/Contender .44 mag ....and no doubt they would go faster from a rifle brl. and still be just as accurate in a micro groove .44.
 
fingers: Horse pucky! That is likely from a bullet too small and too soft with the result you were getting slippage. Possibly using bullets intended for handguns at higher velocity in a rifle. The micro groove will work fine although you may find .002 oversize will work better. If you do the math you will find Micro Groove actually has more support surface for the bullet than conventional barrels. But I do think the lands are a bit shallower so good fit and alloy are necessary. Shooting jacketed over cast will not make cleaning easier. It will lay a layer of copper over the lead. All copper should be removed from the barrel before using cast as the copper tends to grab the lead. If you are going to shoot cast, shoot cast alone. If you switch to jacketed then be prepared to remove all copper from the bore when you go back to cast. If you have a properly fitting bullet and the correct lube you will likely be able to shoot quite a lot of rounds before cleaning at all is needed. If you get lead traces in the barrel the combination is not right. A wash of lead near the muzzle is an indication that your lube isn't doing it's job and is being exhausted before the bullet leaves the bore. Buildups of lead in points along the barrel are another problem entirely.

If your bullet, lube and rifle are in tune you should get virtually no leading after shooting many rounds and a tight bore brush will usually leave the bore clean as a whistle.

It is a good idea to slug your rifle and by pushing a slug slowly through the bore try to feel for any tight spots. These are likely to be found adjacent to any dovetails cut in the barrel for sights, magazine tube attachment, fore end attachment etc. If there are any these can be problematical as they will size your bullet down as they pass by them and open the door to gas cutting of the bullet. These spots can be lapped out with care.

A good source for shooting cast through Micro Groove is to talk to Marshall Stanton at Beartooth Bullets who has done a lot of work and load devlopment for them.
He has a web site as he is a commercial bullet caster of some repute.
 
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