Lead bullets and Marlin's Microgroove rifling

[Silverado]

Please tell me your experience. I understand these 'microgroove' rifled barrells have a reputation for being inaccurate firing lead bullets.

 

[Rudy H]

I have been shooting lead bullets for years with no problem. Actually they have been very accurate. But my loads are not hot loads. In no way factory power.
I have been using it for cowboy action shooting. Originally when I got it I tried lead with hot rounds. Very bad results.

 

[Levi Garrett]

Perhaps due to a softer lead mix, as velocity goes up so should hardness

 

[John Y Cannuck]

I've heard both. I think if your velocities don't push the envelope, it will work out fine.
Of course you will need to slug your bore, get the right size bullet, and shoot hard lead with a gas check for any serious velocities.

 

[Rudy H]

So I said to myself "I wonder what the bore looks like".

Not much depth of field at this magnification. F22 for all you photographers.

It looks a lot better than the photo. Some loose crap in the barrel with no visible lead buildup on the barrel. Looks like the next bullet would clean it out. Don't know if it's unburnt powder. I'm using Universal Clays. I can't use it in a 44 mag handgun because of the unburnt flakes left behind. (A pain after the flakes get under the extractor) With the rifle it has more time to burn up.

Considering I have not cleaned the gun for at least three years (about 800 rounds ) I think it looks ok.

 

[hornhead]

hi silverado:
the best thing to do with the micro groove barrel is to try some cast bullets in it. they seem fine in some cases, others poor.
for the most part i think it depends on velocity and hardness.
if you want when you come down next i'll give you some 405 grainers and some 450s. they're both "bullet barn" stock and there's a distributor in calgary.
not super hard and no gas checks. they worked fine for me in my sharps 45/110 but i only used pyrodex.

 

[Johnn Peterson]

My Marlin 444 has micro groove rifling and given the choice I'd rather it wasn't. A few 'things' that seem to help are, hard cast, sized 0.001" to 0.002" greater than the bore diameter, and gas checked bullets for the higher velocities.

 

[ben hunchak]

Tested Chambers' hard cast 325gr.WFN GC at full velocity in a microgroove .444 Marlin and had no leading or accuracy problems, sized .430" , bhn of 22, this same combo dropped a very large Whitetail buck last year for it's owner, entered chest from the front and exited in front of left hip, major damage to internals.

 

[Salty]

Please tell me your experience. I understand these 'microgroove' rifled barrells have a reputation for being inaccurate firing lead bullets.

I've had 45-70 loads grouping about a foot at 100yds

I've had 375 winchester doing almost as bad.

Then with a little fiddling around I've got both the above shooting way better than i can with steel sights.

Like said above you might need to slug your bore or otherwise figure out what you need for a tight fitting bullet. Gas checks rock. If in doubt slow it down,..

 

[Fall Guy]

I wanted to shoot some lead bullets in my 336 30-30 last year and was very surprised at the cost of them. More expensive then I had imagined. I am still at the drawing board in terms of load development and what I had managed so far (light target loads) was nothing great.

I spoke with a Marlin/lever GN at our Club regarding lead bullets and he warned me to be careful about leading. As has been said, watch the velocities, hardness and use GC's when needed.

 

[Levi Garrett]

I load cast at the same speed as jacketed , with a gas check , Lyman 173 gr
They rock, fired at a log length wise, 10 dia , 20 inches long @ 25 meters. The bullet went in 12 inches curling the wood on the way through , and came apart into 3 pieces at the end of the run. Cast bullets if run hot are just like copper solids for penetration

 

[Silverado]

hi silverado:
the best thing to do with the micro groove barrel is to try some cast bullets in it. they seem fine in some cases, others poor.
for the most part i think it depends on velocity and hardness.
if you want when you come down next i'll give you some 405 grainers and some 450s. they're both "bullet barn" stock and there's a distributor in calgary.
not super hard and no gas checks. they worked fine for me in my sharps 45/110 but i only used pyrodex.

Thanks hornhead, but the microgroove's in my 30-30. The guide gun is cut rifled and I have shot lead through it no problems.

 

[Silverado]

I was actually hoping for some reduced load plinkers for the 30-30. For full loads, I'll just use jacketed.

 

[wade]

i use the bullet barn .303 gas check bullet in my 30 wcf , got them to size to .309 worked fine its 180 gr flat nose,shoots 1.5 inch group to 75 yds, 10 grs unique - 1150 fps , i have shot them in my ,308 a little faster, i think as levi says you could shoot them up to 2000 fps in the 30/30

 

[hs4570]

Microgroove in .444

own a 1970s Marlin in .444 Microgroove 22 inch brl. ....3x9 bushnell


Lee 310 gr gas check...52 gr. H335..2054..2010..2026 fps..3 shots/100 yds 1.50 inch.

Nei 330 grain plain base with "reversed" gas check..54 gr. H335..2052..2067..2037 fps.../3shots/100yds/ 1.40 inch...

both fired " unsized" and at . 430 and .431 inch...if sized .429 just get 4 inch groups....


hs45/70............your mileage may vary

 

[Salty]

I was actually hoping for some reduced load plinkers for the 30-30. For full loads, I'll just use jacketed.

Well then your on the right track I figure Silerado. I haven't loaded cast in 30-30 yet but I worked on a load for my 375 winchester (same case) and ended up at 31.0 grains of imr 3031 under a 265gr gas checked bullet from the bulletbarn; which is about a grain under max in the 48th Lyman manual. This gave right at 1600 ft/s and MOA accuracey at 100 yds

I'd look for a gas checked bullet for your 30-30 (you can do without, but this solves several problems from the get go), at .309 or .310 in diameter. You should be able to find good gc bullets for ~ 10 cents each. You almost always want to be a thou or two bigger with mg rifling it seems and as others have said. Data from Lyman again for a 170gr cast flat point starts at 22.5 and max.s at 28.5grains of 3031 for instance. I'd probably start at the lower end (1600 ft/s) and work up until accuracey opens up which would likely be well before the max which is listed at 2000ft/s plus. In my experience this is too fast for most combinations to give you good accuracey, and I usually find the sweet spot in various guns from 1500 to about 1750 ft/s which kills paper and tin cans just fine

 

[hs4570]

30/30 cast Lee 200 gr.

Lee 200 grain gas check.. wheel weights.. .310 (unsized) 94 winchester 3x9 bushnell

17.0 gr. A2400 powder...1664..1669..1651 fps..3 shots/100yds/ 1.50 inch

shot in 94 win..t/c carbine..340 savage and stayed under 1.75 inch in all three..

.......your mileage may vary

 

[Karl]

17gr of SR4759 under a 173 gr G.C. bullet has good accuracy for plinking with 30-30.

Same load in a 38-55 265gr G.C.

I have tried paper-patching a 310 gr plain base, pure lead bullet for the 444 Marlin - Worked ok - cant remenber the exact load - lots of farking around tho.

 

[Why not?]

The most important thing when using cast in Micro-Groove rifling is that the bullets not be too small in diameter.

In 30 cal, use at least .001 over size. That is .309, or better still .310, will shoot much better than .308 sized bullets.

 

[ben hunchak]

MT Chambers supply can supply hard cast 173gr. Flat point Gas Check bullet in .309,.310, .312", as well as many diff. designed Spitzer Gas Check designs for other .30 cals. and .303s.