Barry in IN

Cast Bullets in the M1941

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I thought others might be curious about using cast bullets in the Johnson semi-auto rifle. I'm no expert on either Johnsons or cast bullets, but thought I'd share what I have found in recent experiments.

I know this is long, but since cast bullets are so far from the norm with these rifles, I was afraid to shorten it up and leave something important out.

I only recently started seriously messing around with cast bullets in rifles. In fact, aside from some cast loads in my 45-70 rifles, I've never shot any cast bullet loads in rifles until a couple of months ago.

I have never casted a single bullet of my own (but am accumulating the things to start).

I'm saying all of this to make it clear that I'm not one of those hardcore cast bullet guys who shoots cast in everything and has a bunch of top secret voodoo magic formulas to make cast bullets shoot well.

I just tried cast bullets in my M1941 Johnson out of curiosity.

While I know people do it, I had not considered shooting cast bullets through any semiauto, let alone a Johnson.

Until...

When I got my JSAR's barrel back from Joseph Scott, the new parkerizing made it fit tight in the radiator and action. I'm not complaining, but rather, I was pretty happy since it snugged all of it up a little. The parkerizing at the wear/contact points smoothed up soon, so it fit really well.

On that first trip to range, I could work the barrel back and forth by hand, but the barrel latch's spring would not quite return it forward on it's own. The only ammo I brought was loaded with 147 grain FMJs, but the powder charge was a little on the light side. In addition, Mr Scott had installed a new main (recoil) spring, so it was at full strength. I had little hope it would work, between the tight fit, new spring, and using light ammo, but decided to shoot it to start wearing it in.

It worked just fine.

So that got me thinking- How lightly loaded can the ammo be and the Johnson still function?

I had already loaded some cast bullets in .30-06, but had not planned on using them in the Johnson. Since I had them, I decided to start with those loads and see where it took me. It they were a dismal failure and scattered hits all over the paper, I would drop the whole idea.

I tried them, and they shot pretty well. I did not expect them to function the rifle since they weren't loaded with a semiauto in mind, and they didn't. What I didn't realize then was how close some were to being functional loads.

On my first trip to the range, I used two bullet designs. I buy my cast bullets from Montana Bullet Works, BTW. He will make most bullets sized to the diameter you want, and often gives you a choice of what alloy (Linotype, heat-treated lead/tin, etc) and sometimes a choice of lube.

I used the Lyman #311041, which was originally designed for the .30-30 I think. The other was the RCBS 180-FN, which is similar.

The Lyman weighed 173 grains, and the RCBS weighed 180.

Both were cast of Linotype (hard stuff).

Both were sized to .309", and lubed with LBT Blue lube.

Both have crimp-on gas checks.

I shot at 50 yards. That is rather close, but I had a few reasons for it, not the least of which is that I didn't know how far off the point of impact would be from the service load and wanted to make sure I hit paper.

These first groups are all five shot groups.

They were all fed from the magazine. The bolt was always ran by hand, but they were fed from the magazine and not hand placed in the chamber.

Velocity was chrono'd at 15 feet from the muzzle.

I used a front rest only. I was concerned the rear sling swivel would catch in my rear sandbag and recoil inconsistently, so I just went without it.

In some loads, I tried a 1/2" square piece of tissue paper pushed into the case over the powder to hold it in place. I thought I'd see if that made any difference by keeping the low charges from moving around inside the case.

This rifle is still new to me, and I yanked a few shots. There were a lot of 4+1 groups, with four in a group then one away from the group. I don't think I yanked that many out, but the evidence is that I did. So in cases where there was one odd shot, I am listing that in the stats.

173 Lyman:

25.0 grains of IMR 4198 went 1920 fps and made a 2 3/8" group. Four shots went into 1 3/8"

30.0 grains of IMR 4895 went 1792 fps and made a 2 3/4" group. Four in 1 1/2"

30.0 grains of IMR 4895 (with tissue wad) went 1788 fps and made a 2 1/8" group.

180 RCBS:

25.0 grains of IMR 4198 went 2043 fps and made a 3 1/8" group. Four in 2 1/8".

30.0 grains of IMR 4895 went 1875 fps and made a 1 7/8" group. Three went into one 5/8" hole.

30.0 grains of IMR 4895 with tissue wad went 1847 and made a 2 1/8" group. Four in 1" even.

This showed me that it would at least keep them on paper and the project was worth pursuing. All but one load was in the general area of 2-2.75". Discounting the stray hits, there were several 1" to 1.5" groups. That may not sound earth-shaking, but isn't bad for the first attempt of just picking some loads that I have heard/read of other people using. And the group sizes translated to 2-5 MOA, which is about where I've been with surplus military ball ammo. There was zero evidence of leading.

It gave me encouragement to try more.

I wanted to see if I could make it function with cast loads, and then work on improving accuracy.

I did some looking online and found some info on cast bullet loads for the M1 Garand. I was surprised to see IMR 4350 favored for cast bullets in the Garand, since it is usually a no-no in that rifle. Being a slower burning powder, it gives higher gas port pressures than those in the 4895 range. I've been led to think that Zeus would come down from the mountain and throw lightning bolts at you for even thinking about trying it.

But apparently it's a different ballgame with cast. Compared to attempts to load service or match ammo with 4350, the powder charges are lower so there is less gas volume to begin with, and using bullets that are on the heavy side helps too by delaying the arrival of these gasses to the gas port. I'm still not fully convinced and ready to shoot a bunch through my Garands, but it sounded like the recoil impulse might make the Johnson function.

More reading showed that slightly heavier charges of IMR 4895, along with slightly heavier bullets, have operated Garands just fine.

So my next direction would be to use either heavier bullets, heavier charges of IMR 4895, or use IMR 4350 with or without heavier bullets.

I didn't have any heavier .30 caliber bullets, so used the heaviest I had- the RCBS 180 FN- and confined my next experiments to using it.

The two powder charges that kept coming up in my research were 38.0 grains of IMR 4350; and 35.0 grains of IMR 4895.

With IMR 4350, I would start at 35 and work up.

That 35 grain charge of 4895 was only three grains more than the mild load I had tried already. With the IMR 4895, I decided to start at 33.0 grains and work up to 35.0 to see if it would function.

My main concern right now was to see what would make the rifle function. Accuracy would come later. I just wanted a low-end baseline functioning charge to start from. With that in mind, I only loaded only three rounds of each powder charge. I thought I'd just creep up on the minimum charge for function.

It didn't take much creeping.

Back at the range today, here is what happened:

I started with the IMR 4350. I loaded the rounds singly this time to see if and when the bolt would lock open.

IMR 4350:

36.0 grains of IMR 4350 ran 1840 fps. All three rounds ejected. Two of the three rounds locked the bolt open. Wow, the first try was close. The shot that did not lock it open was the one that gave the lowest velocity of the three (1933 fps). Apparently, the difference between working and not working fell somewhere in that area.

37.0 grains averaged 1979 fps. All three rounds ejected. All three locked the bolt open.

38.0 grains ran 2054 fps. Since this charge was the "goal", I had loaded five rounds of it. All five ejected. All five locked the bolt open.

IMR 4895:

My 4895 starting charge of 33.0 grains ran 2024 fps and functioned right off the bat. All three ejected. All three locked the bolt open.

I didn't try the heavier charges. I plan to go back and try lower charges to see where the cutoff is.

I wasn't trying all that hard for groups today, as I was mostly trying to find the low end point where it would function with cast bullets. Even at that, these loads shot better than the first ones. However- They were three shot groups as opposed to the five shot groups (except one).

Remember, these groups are at 50 yards, not 100 or more.

All with RCBS 180 FN.

36.0 IMR 4350: 1 3/4"

37.0 IMR 4350: 1 1/4"

38.0 IMR 4350 (5 shots): 1 1/2 (four of those went into 1/2")

33.0 IMR 4895: 3/4"

So it's looking good. I now know it can function in this range, and I have hope for more accuracy.

Even if I quit now, I have a couple of 180 grain cast bullet loads that run 1950-2000 fps or so, function the rifle, and shoot pretty well. And there is still no barrel leading that I can see.

Just thought I'd share if anyone was curious. I think it's pretty interesting and impressive that the good ol' Johnson runs just fine with a load that is so far from the military M1 or M2 loads.

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Update:

I have since tried other cast bullets in mine. I got it to operate at an even lower velocity by using the Saeco #315 bullet, which is almost the same weight as the RCBS bullet I tried the first time. I got it working at a little under 1900 fps with that bullet.

Tempting fate by going really slow, I got it "almost working" with a really light load that ran 1587 fps with that same bullet. Of five rounds, three ejected cocked the hammer and chambered the next round, but two had to be manually ejected. The first two were the failures, and I'm guessing having more rounds in the magazine caused enough greater drag against the bolt to slow it down too much. With those two rounds gone, the drag was reduced and it ran.

Going to a slightly lighter bullet, I tried the RCBS 30-165-Sil. Using the same powder charge that worked with the 180s, the 165 ran it just fine. I can't find the chrono figures (maybe I didn't chrono them?) but would guess they were running in the low to mid 1900s.

Not bad- A load using a bullet of similar weight to the 173 grain military bullet, but traveling at under 2/3 speed, operated the rifle.

All this makes me think the Johnson was pretty forgiving and would have still ran with the bolt slowed down by considerable filth buildup.

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Barry, I only reload 50 BMG for my MaDuece. I've never loaded for anything else. I really enjoyed your essay on reloading for the Johnson. I always wondered what my buddies enjoyed so much about reloading? If your time is cheap, and now mine is, then you can reload for less than store bought ammo most of the time. But you've brought up a point of view that I hadn't considered. That is, the enjoyment of reloading for a special rifle in order to get the receipe just right for both the rifle and the accuracy of your own ammo. I do have a friend who reloads 30.06 for his deer rifle, (and mine). He uses a certain powder, Nosler bullets I think, and one particular brand of brass. He has his reloaded ammo down to a science. He can even make my target shooting look good, because every round travels the same path at the same velocity. It does make a heck of a difference. Thanks for sharing your experience with me...and the group! M48TANKER Oh by the way: For Sale or Trade for 1941 Johnson. :rolleyes:

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It was interesting to me that it would function with something so far from what it was designed for.

I started using those bullets in the 180 grain range because I thought a heavier bullet would make up for the reduced velocity. Velocity is a limiting factor with cast bullets. They can be shot faster than most people think, but there is still a limit. It stands to reason that a 180 @ xxxx fps would give a bigger push to the bolt that a 165 or 150 at the same speed.

After having some success with a 165, I want to keep fiddling around to see what the bottom end limit is there.

Then I want to see how a 150 will do. That may be pushing it. If not, I have moulds down to about 115 grains, but I have little hope there!

It was also interesting to me how much an effect magazine capacity had. If I loaded ten rounds, I had to run those 180s over 1,950 fps to get it to function with all of them. Loading only five in the magazine let it work fine at under 1,900 fps. If I only loaded three rounds in the magazine, I could go all the way down to just under 1,600 fps. Obviously, having more rounds in the mag increases the drag against the bottom of the bolt, and I appear to be right at the range where it can make a difference. Funny how it's effect dropped so much at three rounds.

Yes Tanker, this is what handloading will do to you. I might never have cared much about things like this, but having the means to find out myself...well, I can't help but investigate it. Pushing the envelope to find limits is more interesting if you have the means to do it yourself, even if it's finding the lower limits!

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I got a heavy .30 cal mould recently, a discontinued Saeco #308. This makes a bullet weighing a whopping 218.5 grains on average from my alloy.

I couldn't help but think I could get it to work in the JSAR at even slower speeds.

I tried it out yesterday using IMR 4350. My starting load was 35 grains, which I arrived at by knowing some cast bullet shooters use the very similar Lynan 311284 with 40 grains in their Garands. I thought a five grain reduction would put it right around the edge of functioning.

As it turned out, 35 grains operated the Johnson just fine.

That 35 grain charge averaged 1555 fps, operated the rifle, locked the bolt open on the last round and made a 2-3/4" group. This was at 50 yards because I had no idea where the POI would be. I wasn't even thinking much about group size, and checking for function. I decided to try a little harder on the next load.

The next step up was 36 grains, which went slightly faster at 1576 fps, worked fine, and made a 1-3/4" group. Remember, this us at 50 yards.

Finally I tried the 37 grain load. There was a good jump in velocity there to 1693 fps average. Of course it worked the action fine. The group was the smallest of all at 1-1/2".

It had occurred to me that although I was shooting five shot groups, I should fill the magazine in case that caused more drag on the bolt. I did that- loading ten and shooting five and it worked fine.

I tried these same loads in a Garand and an M1903a3. The Garand operated with the 36 grain charge but the 35 grain would only run the bolt far enough to eject the empty.

I need to head back out with some lighter charges to see where the Johnsons's threshold is with this bullet. Getting it to run at the mid 1500s even with a heavy bullet is impressing me but it makes me want to see how low it will go.

Though not pertaining to Johnson info at all, I found it interesting that the M1903 liked none of this. That rifle has a two-groove barrel and they prefer cast bullets with a long bore riding nose. This bullet is about half groove-filling bands and half bore riding nose but I didn't think it would do as bad as it did. The first load went 10" with one tumbling (but within the group) and the next load went 12".

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I should also add that this bullet has a pretty blunt nose rather than the streamlined GI bullet. That didn't matter to the Johnson, but it did matter the the Garand and the 1903.

I could only load five rounds in the Garand because the fat noses dragged against metal within the receiver opening. Using only five rounds allowed them to wiggle around to find a place to rest. Loading a full eight rounds caused the clip to stop dead long before seating.

The 1903 would accept them in the magazine but would not feed all five into the chamber. When it did, it was only those feeding from the left side of the magazine and that was sporadic. A little guidance from my fingers got them all to work.

So this is one case where a semiauto was more dependable than a bolt I suppose.

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I don't know how useful the info is, but I found it interesting. I'm a lot smarter about cast bullets now than when I started but I've found it doesn't take much to make them work in almost anything. Still, getting them to function so well through a semiauto that was meant to be operated by ammunition firing bullets nearly twice as fast impressed me.

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