Loading for 44 Mag in Microgroove barrels

[Dragoon 45]

I am asking this question for a friend as I have no experience with microgroove type rifled barrels and he doesn't have internet access.

He has a Win 94AE in 44 Mag with microgroove type rifling in the barrel. He bought some factory 44 Mag ammo loaded with semi-wadcutter 240gn lead bullets and had terrible accuracy. The ammo in question was rated at around 1300fps out of a pistol barrel.

Using cast bullets what is the best way to load for this rifle in general?

Will cast bullets require that velocities be kept down to 44 Spec levels or can they be loaded to full 44 Mag levels?

Are there any major pitfalls to watch out for in loading cast bullets in this type rifling? Any comments or suggestions would be welcome.

Thank You.

[jh45gun]

You sure its not a Marlin??? I have never heard of Winchester having a micro groove barrel.

[mike in co]

just do a search on this forum about microgroove and lead.

and yep its not likely its both a winchester and micro groove.


mike in co

[crazy mark]

My Winne AE in 44 Mag has regular rifling. Shoots everything just fine. It's a trapper model.

[longbow]

Personally I have no problem with microgroove barrels. In fact Like them. The problem I had with my Marlin .44 mag. microgroove barrel had nothing to do with the microgroove rifling. It had everything to do with boolit fit.

The Marlins have a reputation for fat barrels and mine is fat at almost 0.432". Accuracy was poor with typical boolits cast from moulds designed for the nominal 0.429"/0.430" barrels and it leaded badly.

I fattened up the boolits and all is well. I am now shooting boolits of 0.432" to 0.434" with good success.

I would slug the barrel and measure groove diameter to find out what he has then cast and size boolits at least 0.001" over groove diameter, or even better 0.002" to 0.003" over groove diameter.

While I don't like gas checks and shoot mostly plain base, gas checks can sure help so consider a gas check mould that casts large enough to size for the groove diameter.

I am not sure what factory moulds cast fat enough and I lap most of mine to suit.

There is an NOE mould available here:

http://castboolits.gunloads.com/showthread.php?t=60035

It is a light one but fat and gas check design.

You might also check here:

http://www.mp-molds.com/

E-mail or PM Miha to ask what he has in stock. He did have some extra H&G #503 Cramer style moulds that cast a semiwadcutter at 0.432". R=They may all be gone but if he has one they are beautiful moulds and good prices.

Longbow

[Nobade]

The 265 grain Ranch Dog boolit works great in mine. It casts out at .433" and fits the fat bores well. BTW, is it possible he has a B92? I had one of those in 44 mag, and it had what could be described as microgroove rifling.

[Dragoon 45]

It is a Winchester 94AE and it has microgroove type rifling. I have seen the rifle. Evidently Marlin's patent on that type of rifling ran out and Winchester started rifling its 44 Mag barrels with that type rifling shortly afterwards. He did a chamber cast and slugged the bore to confirm the type of rifling. He did confirm that the bore was overbored, somewhere around .434 if I remember correctly. According the SN, the rifle was produced shortly before Winchester went belly up and closed down their plants in Conn.

He went to a local gunshop a couple of weeks ago, and found 4 or 5 other Win 94's in 44 Mag with the same type of rifling in their selection of 94's.


You sure its not a Marlin??? I have never heard of Winchester having a micro groove barrel.

[cabezaverde]

I have a Win 94 in 44 mag with a microgroove, though mine is an older one.

We did a group buy mold a few years ago for an oversized 210 RNFP plain base 6 cavity Lee. I have this one.

I think there was another buy for the same with a gas check a while later. Let me know if you need a few boolits.

[MTWeatherman]

I am asking this question for a friend as I have no experience with microgroove type rifled barrels and he doesn't have internet access.

He has a Win 94AE in 44 Mag with microgroove type rifling in the barrel. He bought some factory 44 Mag ammo loaded with semi-wadcutter 240gn lead bullets and had terrible accuracy. The ammo in question was rated at around 1300fps out of a pistol barrel.

Using cast bullets what is the best way to load for this rifle in general?

Will cast bullets require that velocities be kept down to 44 Spec levels or can they be loaded to full 44 Mag levels?

Are there any major pitfalls to watch out for in loading cast bullets in this type rifling? Any comments or suggestions would be welcome.

Thank You.

I have a Winchester 94AE 44 Mag Trapper from the early 80s. Although that barrel is stamped Winchester, it is indeed a Microgroove barrel which slugs at .4325. Short answer to your question is to treat that Winchester like a Marlin when it comes to cast bullet loads due to the oversized groove diameter.

Most likely those 240 gr. lead bullets your friend used were .430 diameter...most commercial cast are.

Best and only way to load for this rifle is to use a fat bullet of at least groove diameter...I use a .433. It the groove truly is .434 (that's about the largest Microgroove I've heard of)...it will require at least a .434 bullet. Unfortunately, most moulds are rated at .429 or .430 and it would be pure luck and highly unlikely (but possible) to drop a .432 or larger bullet from one. Answer is to lap out the mould...a rather time consuming project on a steel mould but discussed at length in various threads on this forum. Relatively easy solution would be to use a Ranch Dog mould which typically drops about a .433 bullet and lap it slightly if needed (aluminum laps much easier than steel). However, last I heard Ranch Dog is no longer in the business of selling them so you'd have to find someone willing to give theirs up and that likely wouldn't be easy. Best but costliest solution would be to order a custom mould if the friends wallet can handle it.

With a proper bullet you can load that .44 Mag to its full potential. That would be a fat bullet with a gas check. I'd also recommend a quenched or heat treated bullet to harden the bullet. Use a plain based, low BHN bullet in a Microgroove barrel and you'll indeed have to load closer to .44 Special performance. Use an undersized bullet and you'll never achieve acceptable accuracy.

[jlchucker]

I've got a Winnie 44 mag trapper--angle eject but prior to the lawyersafeties. I never really looked down the barrel to see. I just started loading Lyman 429215's in it, sized .429 and cast from wheelweights with 10 percent pure lead (sometimes with some range pickups thrown in) and started shooting. That little rifle, in spite of having a lever link that is too narrow for the receiver, with the expected rattle, shoots minute-of-clay-pigeon fragment at 100 yards all day long. I've probably put over 1,000 rounds through it over the years, and never had a problem.
Maybe I need fatter boolits???? I'll worry about that when the thing gets to be inaccurate.

[Dragoon 45]

Thank you for your info. I will pass it on to him.


I have a Winchester 94AE 44 Mag Trapper from the early 80s. Although that barrel is stamped Winchester, it is indeed a Microgroove barrel which slugs at .4325. Short answer to your question is to treat that Winchester like a Marlin when it comes to cast bullet loads due to the oversized groove diameter.

Most likely those 240 gr. lead bullets your friend used were .430 diameter...most commercial cast are.

Best and only way to load for this rifle is to use a fat bullet of at least groove diameter...I use a .433. It the groove truly is .434 (that's about the largest Microgroove I've heard of)...it will require at least a .434 bullet. Unfortunately, most moulds are rated at .429 or .430 and it would be pure luck and highly unlikely (but possible) to drop a .432 or larger bullet from one. Answer is to lap out the mould...a rather time consuming project on a steel mould but discussed at length in various threads on this forum. Relatively easy solution would be to use a Ranch Dog mould which typically drops about a .433 bullet and lap it slightly if needed (aluminum laps much easier than steel). However, last I heard Ranch Dog is no longer in the business of selling them so you'd have to find someone willing to give theirs up and that likely wouldn't be easy. Best but costliest solution would be to order a custom mould if the friends wallet can handle it.

With a proper bullet you can load that .44 Mag to its full potential. That would be a fat bullet with a gas check. I'd also recommend a quenched or heat treated bullet to harden the bullet. Use a plain based, low BHN bullet in a Microgroove barrel and you'll indeed have to load closer to .44 Special performance. Use an undersized bullet and you'll never achieve acceptable accuracy.

[MTWeatherman]

I've got a Winnie 44 mag trapper--angle eject but prior to the lawyersafeties. I never really looked down the barrel to see. I just started loading Lyman 429215's in it, sized .429 and cast from wheelweights with 10 percent pure lead (sometimes with some range pickups thrown in) and started shooting. That little rifle, in spite of having a lever link that is too narrow for the receiver, with the expected rattle, shoots minute-of-clay-pigeon fragment at 100 yards all day long. I've probably put over 1,000 rounds through it over the years, and never had a problem.
Maybe I need fatter boolits???? I'll worry about that when the thing gets to be inaccurate.

Since you've never looked down the barrel or slugged it, I'll take a wild guess here and say that you don't have a .434 Microgroove barrel but a standard 6 groove .429 barrel. Commerical moulds are made for those barrels. That's why they're designed to drop bullets at about .430 (except Lee which usually manages to do no better than .429 in my experience) and firearms shoot perfectly well with those .429 and .430 bullets...including my .44 Mag Blackhawk and most Winchesters, AE or otherwise. However, not true with Marlins as they are large grooved Microgroove. Very few Winchesters were Microgroove...witness that it came as a surprise to several posters on this thread. However, most of those barrels are over sized, just like the Marlins, and need fat bullets to shoot well.

If you have a standard barrel.....a .429 or .430 bullet works well. Based on your experience, I'd guess you don't have an overly large grooved barrel. However, a .429 bullet in a .434 Microgroove barrel would hardly grip the rifling to say nothing about the massive gas cutting and leading that would occcur. Those Microgroove lands aren't very tall. Be surprised if the bullet didn't keyhole.

You can never argue with success. In your case, keep shooting those .429s. That 429215 is a great shooting bullet by the way...I've got it but had to lap the mould out for my rifle. Believe me, not something I'd ever spend the time doing unless it was necessary. If you ever wish to tune the rifle for more accuracy, you might try a .430 bullet. You could well pull those groups below minute of clay pigeon...most rifles do the best at at least .001 over groove...but no guarantee. My 94 will handle under 2 inch groups at .0005 over groove diameter. With the right bullet and load those 94s (and Marlins), Microgroove or otherwise will shoot better than most give credit for.

In my .4325 groove Winchester, I'll stick with the .433s. Bullets need to be sized to the barrel if you're shooting lead. No doubt in my mind that the problem with Dragoon,s friend's accuracy issues are those undersized bullets. Until he gets some "fat" ones no load development is going to help him.