Minimum bullet size

[cmat1120]

Hello, I was wondering if .001 over groove is a really hard minimum bullet size or if it just needs to be bigger than the grooves and .001 is just the standard amount. The reason I ask is I have a marlin 1894 in 44 mag that slugs out at 0.4315". 0.432" bullets aren't too hard to find, but I can't find any decently priced 0.433" bullets. I want to get the best I can out of the rifle, but the only 0.433" bullets I can find are almost 3 times as much as 0.432" I can find(not because of the size, but just the standard cost from those sources). Adding that much to the cost of reloading would mean I wouldn't be able to shoot nearly as much.

Also I did run about 50 0.432" swc-hp bullets through it this weekend and didn't notice any leading, but I was shooting steel so I don't know how accurate they were. The rounds I were firing were just under max load for unique powder so probably around 1400 fps out of the rifle. I didn't bring a chrono so that's the best estimate I have.

[fredj338]

I think it is often quoted as min but as long as the bullet is over sized, you generally get good results. I do know that even 0.0005" undersized can cause accuracy & leading issues.

[MT Gianni]

I don't care about leading but grouping. If I can't get a decent group with the 0.001" over groove diameter it could be because of a barrel flaw. It could also be alloy ir other issues too. IIRC, Veral Smith stated that he didn't care for micro-groove bbls as they tended to vary in diameter through the bbl. If you're shooting with enough pressure to keep the bullet expanded and filling the grooves it should do fine. If your groups aren't where you want them to be casting your own or finding some .432" for sale would be my next move.

[cmat1120]

This is a new marlin so it does have ballard rifling although the rifling still looks pretty shallow. I'm out of bullets now though so I need to order more and I'd prefer to order in bulk. I suppose I could just put out the money to get 1-200 each of 0.432 and the pricey 0.433 before ordering 1-2000 of one type. I figured I'd ask in case there was a definitive answer on this topic so I didn't waste money, but it sounds like maybe its more of a guess and check kind of deal. I am planning on trying to get bullets of a bhn close to 12 so they shouldn't have much of a problem expanding at ~1400fps from what I understand.

I'd love to start casting my own, but I don't have the space for it currently nor the time as a junior in college.

[bmortell]

you should of did a proper accuracy test with sandbags while you had them. id get whatever a small batch of each come in, and test accuracy with the loads you may use. if .432 is accurate enough and isn't leading bad it don't really matter what the numbers are. id rather clean my barrel sometimes than spend 3 times more on ammo as long as they shoot accurate enough.

[Outpost75]

Throat size, not groove size!!!!!!!

[Rcmaveric]

Depends on the gun and your mileage. I have heard guys preach bore diameter. There was a fella not to long ago who lost accuracy as he increased diameter. So he sized his 308 to 308. I started off the .002 over bore. Then comparing apples to oranges i tried the throat sizing. I noticed increased accuracy with throat sized bullets. So, that's the way i go now a days. So, in all fairness bore to throat diameter is your window. See what the guns like.

[cmat1120]

Throat size, not groove size!!!!!!!

I'm shooting in a rifle not a revolver, although I will shoot these in my revolver too assuming it chambers. 0.432 has no problem chambering in my revolver so hopefully 0.433 does as well if I end up having to go that big.

Also to clarify lever action rifles generally don't have a throat. They pretty much go straight from chamber to rifling.

[waksupi]

I'm shooting in a rifle not a revolver, although I will shoot these in my revolver too assuming it chambers. 0.432 has no problem chambering in my revolver so hopefully 0.433 does as well if I end up having to go that big.

Also to clarify lever action rifles generally don't have a throat. They pretty much go straight from chamber to rifling.

The chamber is the throat. I like to find a bullet that slips into a fired case with just a bit of resistance. That is usually the best ticket for a particular rifle.

[cmat1120]

The chamber is the throat. I like to find a bullet that slips into a fired case with just a bit of resistance. That is usually the best ticket for a particular rifle.

Based on that I'm going to need a 0.434 bullet then... Measuring the inside of fired cases I'm getting around 0.4335-0.434". I can't find anywhere to get bullets that size. In fact after going back and looking I can't find anywhere that sells 0.433 either.

[waksupi]

Based on that I'm going to need a 0.434 bullet then... Measuring the inside of fired cases I'm getting around 0.4335-0.434". I can't find anywhere to get bullets that size. In fact after going back and looking I can't find anywhere that sells 0.433 either.

You would probably need to order a custom from one of our mold makers.

[cmat1120]

You would probably need to order a custom from one of our mold makers.

I'm not currently able to cast my own. I'm going to try ordering some .433 from Missouri Bullet Company. I'm going to order 240gr rnfp with a bhn of 12. I'll have to order 1000 so hopefully they work. If not I guess I'll have to try selling them on here to someone that can use them.

[cmat1120]

I did a little testing that may or may not have practical meaning. I took some empty cases and flared the rim out to see how much I could flare it out and still be able to chamber. I managed to flare it to 0.456" and it easily chambers in my revolver and with a slight amount of pressure it chambers in my rifle. I know that this isn't a complete test as the throats could still be too small, but based on how easy both chambered 0.432 swc's I think I'll be fine even with a rnfp in 0.433". A wfn would be a little tighter though I think.

[fatelk]

I have an older Marlin 1894 .44 Mag, with microgroove rifling. As I recall, it also slugs at .4315”.

I have .44 mag revolvers and prefer to be able to use the same ammo in rifle and pistol, so the best compromise I found for my guns was .432” bullets. I used powder coated 429421 and 429244 (basically the same except with a gas check). They all work well but I’ve found that for my rifle the gas checked bullets are more accurate, even with lighter loads.

That’s just what works best with my rifle; I understand yours is different with different rifling.

[cmat1120]

I have an older Marlin 1894 .44 Mag, with microgroove rifling. As I recall, it also slugs at .4315”.

I have .44 mag revolvers and prefer to be able to use the same ammo in rifle and pistol, so the best compromise I found for my guns was .432” bullets. I used powder coated 429421 and 429244 (basically the same except with a gas check). They all work well but I’ve found that for my rifle the gas checked bullets are more accurate, even with lighter loads.

That’s just what works best with my rifle; I understand yours is different with different rifling.

Thanks for the info. I just ordered 1000 0.433 bullets. They're a bhn of 12, but I'm only using unique powder so it should be under 1500fps. If these don't work out well I'll either use them in the revolver, use them for soft loads or sell them to someone that can use them. Luckily my revolver is an older single action and seems to have pretty loose chambers.

I'm hoping I can manage to make a plain base work but if not I'll give gas checks a try, but at that point I'll probably have to wait until I can cast my own as I haven't found any gc bullets cheap enough for me to use as range ammo.

I also tested the accuracy of my last 10 0.432 bullets. Unfortunately I'm not positive if I'm not used to the ghost ring sight or the bullets are inaccurate as I got around a 5" group at 50 yards. For reference my groups with standard iron sights at the same distance with my 10/22 and cheap ammo was around an inch with a few flyers in a 10 shot string. I think I might've been trying too hard to center the front post. Apparently with ghost sights that's a no no.

[DougGuy]

If they work in the rifle, and work well, you could always have the revolver cylinder throats honed to chamber the loads that work in the rifle. I have done this a few times so guys can load the same ammo for both.

[fatelk]

I had a terrible time getting any kind of accuracy out of mine for years, with cast or jacketed. I finally found that the tube was binding badly on the barrel. I relieved that and it seemed to help a lot. I tinkered and experimented a lot before finding something that works, but it’s still not a tack driver.

In mine I had to have a full power load with a gas check to get any acceptable accuracy. I saw a lot of targets like your 5”@50 yard groups during all my tinkering. Of course that’s just my rifle, and others here have different stories to tell about theirs, so you never know until you try. Good luck!

[cmat1120]

I had a terrible time getting any kind of accuracy out of mine for years, with cast or jacketed. I finally found that the tube was binding badly on the barrel. I relieved that and it seemed to help a lot. I tinkered and experimented a lot before finding something that works, but it’s still not a tack driver.

In mine I had to have a full power load with a gas check to get any acceptable accuracy. I saw a lot of targets like your 5”@50 yard groups during all my tinkering. Of course that’s just my rifle, and others here have different stories to tell about theirs, so you never know until you try. Good luck!

Thanks I read something about that. I loosened the front cap and only snugged the screws this time rather than cranking them down. I also ordered a rail so I can throw a 4x scope on to take the sights out of the equation until I have a load that shoots well. I know I'm a decent shot with irons as I'm used to the similar sights on the M4 rifle, but I'm definitely better with a scope. With my bolt action rifle and handloads I can shoot .24" at 100 yards. If I can get around 3-4" at 100 yards I'll be very happy. Hardest shot I'd take that could matter would be around 125 yards with a 6" kill zone(deer or elk).

I might try some factory JSP ammo too just to see how it shoots. And if nothing else my first range session taught me how fun this thing is at under 40 yards shooting steel rapidly.

[cmat1120]

I ordered 1000 0.431 jsp bullets so I'll give those a try for now. I'd like to start casting my own, but I'd prefer to try some 0.433 and 0.434 bullets first to see how they work first before investing in all the equipment. I guess I'll just wait till I've contributed to this forum enough to put a WTB ad in the S&S section and hopefully find someone willing to sell a few of each to test out. I looked into powdercoating, but that doesn't seem like something I'd be interested in doing.

I appreciate everyone's advice and tips!

[tecdac]

You don't say what you are using the rifle for but if you scale back the velocity the softer bullet will expand to the barrel size and your accuracy will go up.