Cast bullets in Marlin 336 Microgroove .32 Special #U26307

[GregT]

Just wondering if anyone has run any kid of accuracy test with a rifle like this? I picked up the rifle not too long ago due to the caliber and the condition which is about 95%. I ran one load with a cast bullet through it and noted a spotlessly clean bore with very few powder grains left in it (SR-4759). (Lyman #321232 170 grains). I got in a shipment of Missouri Bullet Company 170 grain .321", .32/40 bullets yesterday that I am going to try out. This will probably be the main bullet used in this rifle. Any suggestions?
GregT

[Rusty]

The first thing to do is slug the bore so you know exactly what you're working with.

[6pt-sika]

I cast for three different Marlin's in 32 Special and sized for all using a .323 die . Used the RCBS 32-170 , the Lyman 321297 and the RAnch Dog 323-170GC . All worked nicely in my three Marlin's . Used plain old air cooled wheelweights lubed with Thompsons Blue Angel . My guns were made from about 1919-1954 so it covered most spectrums except the micro groove guns .

[GregT]

Thanks fellas! About all I ever hear about Micro-groove rifled guns is that they are as accurate as those rifled in the Ballard style. This is not enough info... Many times I think this is just a repeat of what someone has read or heard. The 1/16 rifling spin is "right" for this type of shooting as the slower spin will stress the bullet less as there is less torque. I will eventually try all the common bullet diameters for this caliber thus the need to slug the bore is not too pressing. I don't know how you would even begin to measure groove diameter once the bullet is shoved through Micro-Groove anyway. I will keep the velocity down and look for signs of leading indicating that the bullet has failed to 'take' the rifling. The real indicator is the accuracy on target paper and whether the bullet will go where the sights 'tell' it to go on target. I appreciate any info you may have to pass on.
Happy Thanksgiving
GregT
Hayward, Wisconsin

[Stan in SC]

I had very unsatisfactory results in using cast .321 bullets in my Winchester 94.I went back to jacketed bullets and get great accuracy.I hope you have better results.

Stan in SC

[GregT]

I hope the accuracy is good. There are tricks that can be used such as ground polystyrene filler on top of the powder. I fill up all airspace with this material which seems to seal the base of the bullet and also clean the bore as the compacted plastic goes down the bore. This technique will usually shrink the group size down a bit all by itself. Jacketed bullets for this caliber are not easy to find at this point as panic buying of reloading components seems to have started again... If you want a shock, check Cabela's "stock" of reloading components and ammunition... This began again right after the election. I had to search the net high and lo for once fired .30-30 casings so that these could be turned into .32 Special brass. Finally found some at Diamd K Brass in Scottsdale, AZ. If something that you did failed, post this also as it may save time.
Thanks,
GregT

[6pt-sika]

Thanks fellas! About all I ever hear about Micro-groove rifled guns is that they are as accurate as those rifled in the Ballard style. This is not enough info... Many times I think this is just a repeat of what someone has read or heard. The 1/16 rifling spin is "right" for this type of shooting as the slower spin will stress the bullet less as there is less torque. I will eventually try all the common bullet diameters for this caliber thus the need to slug the bore is not too pressing. I don't know how you would even begin to measure groove diameter once the bullet is shoved through Micro-Groove anyway. I will keep the velocity down and look for signs of leading indicating that the bullet has failed to 'take' the rifling. The real indicator is the accuracy on target paper and whether the bullet will go where the sights 'tell' it to go on target. I appreciate any info you may have to pass on.
Happy Thanksgiving
GregT
Hayward, Wisconsin

Here's the bottom line of the Micro groove vs Ballard falicy !

I've shot cast in Micro groove and Ballard in about all the calibers Marlin barreled them both . And I've had good or better results all the time and very good to excellent results most of the time .

Plain wheelweight alloy thats aricooled is typically all I ever needed . The only other thing I ever used was water quenched wheelweight alloy for the heavier bullets in the Micro grooved 444's and 45-70's . And by heavier I mean 320+ grains for the 444 and 400+ grains for the 45-70 .

For the 30-30's in the Marlin's I had I sized at .312" , for the 35 REm/356 win i SIZED AT .359" , for the 32-40/32 Special I used .323" , for the 375 WIN I used .379" , for the 44 MAG/444 I now use .433" although I started with .430" and worked my way up to .433" . For the 450 Marlin/45-70 I started with .459" and now use .461" .

Of course there are several others for the 1894 Marlin's etc that could be included . But I found all around the larger I sized the better it shot . Granted I never used what I would call a hard alloy so it could be obturating a good bit . Either way it doesn't matter as they worked for what I wanted .

I only cast for the 44 MAG , 444 and 45-70 now . But a couple years back i shoot several thousand of the RD 311-165GC and the RD 323-170GC at paper and metalic silhouettes with very satisfying results , lets suffice to say my loads were a h....e...l...l lot more accurate then I was from shooting them offhand at the silhouettes .

[6pt-sika]

I hope the accuracy is good. There are tricks that can be used such as ground polystyrene filler on top of the powder. I fill up all airspace with this material which seems to seal the base of the bullet and also clean the bore as the compacted plastic goes down the bore. This technique will usually shrink the group size down a bit all by itself. Jacketed bullets for this caliber are not easy to find at this point as panic buying of reloading components seems to have started again... If you want a shock, check Cabela's "stock" of reloading components and ammunition... This began again right after the election. I had to search the net high and lo for once fired .30-30 casings so that these could be turned into .32 Special brass. Finally found some at Diamd K Brass in Scottsdale, AZ. If something that you did failed, post this also as it may save time.
Thanks,
GregT

For the 32 Special shooting the Ranch Dog 323-170GC , the Lyman 321297 or the RCBS 32-170 I mostly used XMP5744 without any fillers . Typical loads were in the 20-22 grain range , while some folks swear by the synthetic fillers I am not one of them . With 5744 there isn't a need or atleast i never saw it .

[GregT]

I added a Williams Foolproof receiver sight and a slightly higher front sight insert to the original Marlin ramp so that I could precisely shoot this 336. The load I am using is this: cast, 170 grain Missouri Bullet Company .32/40 slug, .321" diameter, 13 grains of SR-4759, Wolf Large Rifle primer, mixed .30-30 cases converted to .32 Rem. Special, bullet seated so action can be easily functioned. We had a blizzard last night and we went from a 60 degree day on Thursday to one that was 15 degrees when I shot today. Also NW wind about 35 mph. 4 inches of snow.
Fired from the bench at 45 yards, 3 shot groups. 3 sighters 1 inch to the left of the bullseye. Two groups fired that clustered in the inch and a half bullseye with room to spare. I checked each shot by walking up and back. Kept me warm. I know that two groups does not prove much, but it shows me that the rifle is inherently accurate, bullets do not lead up the bore (in fact after about 50 rounds or so with this bullet, the bore seems cleaner than when I started). I can get about 60 yards out of my short range and was not real interested in too much more walking than I did. So, more shooting with this load and if it continues to shoot well, I will then start to change the load a little bit to see if I can pull more accuracy out of it.
Always wanted to try Micro-Groove with cast bullets. I am certainly pleased so far.
GregT
15 miles east of Hayward, Wi.

[Rusty]

Greg one of the best investments you'll ever make is to purchase Veral Smith's book from his site http://lbtmoulds.com/

According to Veral a Microgrove barrel is about as close as you can get today to an old Harry Pope barrel. The key to accuracy is good lube on a properly fitting bullet.

[GregT]

Thank you. I took some time on Veral's site. Interesting information.
GregT