This definitely sounds like a case of too small cast bullet for the barrel's muzzle end. Open the chamber and throat to accept larger bullets/ammunition, and you should see improvement. I fixed a Marlin with tight bore ahead of chamber by fire lapping, but if you can't chamber the desired, larger diameter bullet, that won't help.
I think I'm going to have to admit defeat.
- Thread starter Ian
- Start date
quicksylver
Well-Known Member
+1 ..on 300's comments...think you got a Marlin Micro grouve situation going on as well. ..where you need an "overly large " CB.. but have a too small of throat to chamber them...the jacketed and copper plated ones
Are allowing enough grab with the rifling to work ....same thing happens with the Marlin. .
use .312 CB's and they shoot fine in the 336 anything less doesn't...normal size would be .310 , .311
Ian
Notorious member
Wasted another entire day trying to make this thing shoot.
First I tried some of the 225-grain gas checked bullets from the excellent iron mould Tom sent me to try. At 4.5 cents a pop, I'm simply not going to buy Hornady checks to shoot in .45 ACP. I'll buy factory ammo long before I do that. So I tried Josh's aluminum checks which didn't want to stay on the bullets. Damn near ruined my suppressor with them, should have known better than to try running them through it. I got true keyholes at 25 yards and the checks ended up shredding in the blast chamber and second chamber of my can. No other damage other than some faint baffle strikes near the muzzle end of the can. I only fired three of those before I quit, and only one hit the backer at 25 yards.
So back to the powder-coated Lee 230TC. I also tried these in my M&P .45 and they shot very well once I seated them deep enough for this absolutely throatless wonder of Smith & Wesson Lack of Engineering to chamber them....even sized .451". This thing barely chambers factory ball ammo. Since I was getting good groups with the M&P with the bullets seated deeper, (1.200" vs. 1.208") I broke out the AR-45 again. Still getting 2.5" round clusters at 25 yards. This is all with Hodgdon Universal powder because anything faster won't cycle the AR-45 and Unique blows my eardrums out via ejection port noise due to it's weird, long burn curve. So I tried the AM 45 230L, powder coated, sized .4525, .452", and .4515" with different crimps each. No dice, no change in groups. Loaded some more Rainer round noses with the same powder charge, shot a 1" hole with ten, so THAT isn't the problem. Went back and loaded some AM 230C bullets with regular lube and tried them at .4525" and .4515. Worse than ever, 3-4" ten-shot groups at 25 yards. I can hit better than that by throwing a rock.
Size doesn't matter. Front shoulder doesn't matter. Nose profile doesn't matter. Crimp doesn't matter (except for function). Case brand doesn't matter (all same headstamp). Flat base or bevel base doesn't matter. Powder coated or plain lubed doesn't matter. The only thing that matters is whether there is a copper jacked on the bullet, no matter if just thin plating or a heavy, ball-style stamped jacket. I'm simply at a complete loss as to why this thing won't group with any kind of cast bullets.
Maybe I should have gotten some copper-colored powder coat and seen if I could fool this carbine into shooting some decent groups.
First I tried some of the 225-grain gas checked bullets from the excellent iron mould Tom sent me to try. At 4.5 cents a pop, I'm simply not going to buy Hornady checks to shoot in .45 ACP. I'll buy factory ammo long before I do that. So I tried Josh's aluminum checks which didn't want to stay on the bullets. Damn near ruined my suppressor with them, should have known better than to try running them through it. I got true keyholes at 25 yards and the checks ended up shredding in the blast chamber and second chamber of my can. No other damage other than some faint baffle strikes near the muzzle end of the can. I only fired three of those before I quit, and only one hit the backer at 25 yards.
So back to the powder-coated Lee 230TC. I also tried these in my M&P .45 and they shot very well once I seated them deep enough for this absolutely throatless wonder of Smith & Wesson Lack of Engineering to chamber them....even sized .451". This thing barely chambers factory ball ammo. Since I was getting good groups with the M&P with the bullets seated deeper, (1.200" vs. 1.208") I broke out the AR-45 again. Still getting 2.5" round clusters at 25 yards. This is all with Hodgdon Universal powder because anything faster won't cycle the AR-45 and Unique blows my eardrums out via ejection port noise due to it's weird, long burn curve. So I tried the AM 45 230L, powder coated, sized .4525, .452", and .4515" with different crimps each. No dice, no change in groups. Loaded some more Rainer round noses with the same powder charge, shot a 1" hole with ten, so THAT isn't the problem. Went back and loaded some AM 230C bullets with regular lube and tried them at .4525" and .4515. Worse than ever, 3-4" ten-shot groups at 25 yards. I can hit better than that by throwing a rock.
Size doesn't matter. Front shoulder doesn't matter. Nose profile doesn't matter. Crimp doesn't matter (except for function). Case brand doesn't matter (all same headstamp). Flat base or bevel base doesn't matter. Powder coated or plain lubed doesn't matter. The only thing that matters is whether there is a copper jacked on the bullet, no matter if just thin plating or a heavy, ball-style stamped jacket. I'm simply at a complete loss as to why this thing won't group with any kind of cast bullets.
Maybe I should have gotten some copper-colored powder coat and seen if I could fool this carbine into shooting some decent groups.
Ian
Notorious member
$160/1,000 for Rainer 230-grain round nose plated bullets isn't looking so bad right now. I can always plink with my powder coated ones, 2.5" round groups is plenty good for rolling cans at 25-30 yards.
One of my 15-yard benched groups with the M&P was eight of 10 into 1/4" after subtracting one bullet diameter. The other two were nearby and attributed to involuntary muscle tremors and called right as the shots broke. I don't necessarily think my powder-coated cast bullets are the issue. If my bell wasn't already rung from shooting the M&P (meaning my hands get beat-up very quickly and I can't hold steady the rest of the day), I should have gotten out my Kimber 1911 and shot some groups with it to compare.
One of my 15-yard benched groups with the M&P was eight of 10 into 1/4" after subtracting one bullet diameter. The other two were nearby and attributed to involuntary muscle tremors and called right as the shots broke. I don't necessarily think my powder-coated cast bullets are the issue. If my bell wasn't already rung from shooting the M&P (meaning my hands get beat-up very quickly and I can't hold steady the rest of the day), I should have gotten out my Kimber 1911 and shot some groups with it to compare.
F
freebullet
Guest
Holy cow...sounds like ya tried about everything.
I would honestly throat them both. You don't have much to loose at this point and, might gain from trying.
Then maybe firelap the rifle if further testing proved it might be useful.
So.....how much for the ar45?
I would honestly throat them both. You don't have much to loose at this point and, might gain from trying.
Then maybe firelap the rifle if further testing proved it might be useful.
So.....how much for the ar45?
F
freebullet
Guest
Or 450bushmaster & use the same molds you are now
Ian
Notorious member
If I thought there was some issue with the dozen-odd bullet designs I've shot through this carbine, I'd take you up on that, but there has to be something else going on. I have several moulds that my 1911s shoot very well, but this carbine hates them all.
There must be something mechanically wrong with the gun. When I first got it, all my issues surrounded function. None of my pet 1911 loads would function it. I polished and tuned and fussed with magazines and overall was getting decent groups (2.5" at 50 yards with one of my pet 1911 loads which is an AM 45-230L out of COWW +2% tin @ .4525", lubed with Felix lube), but the sharp-shouldered bullet had to be single-loaded so the bolt lugs didn't split and peel the case mouth like a banana. After I got a round nose bullet and powder combo to function the rifle, I noticed groups started deteriorating. Then I found some baffle strikes on the flash hider. After removing the flash hider (which took a torch and a pipe wrench, $^#%^# ham-fisted individual who built this thing thought it was a good idea to use a crush washer and 300 lb-ft of torque on the paper-thin barrel to get the flash hider indexed), it never really shot well again with cast bullets, but has always shot well with jacketed. I think something's wrong with the end of the barrel now. But, the barrel is cut at exactly 16-1/16" and is too thin to counter-bore, so I can't fix it unless I either make a pistol out of it, apply for an SBR stamp, or pin a muzzle device on it that will accept my suppressor. The latter might be the way to go, but presents another challenge: Removing the handguard. The builder used a Sampson Evo handguard that pinch-mounts to some barrel nut adapters and is supposed to simply slip off when the pinch bolts are loosened. When I first got this upper, the handguard was off-center severely (it was obviously mis-machined) and fixing that required removing the handguard. It took me three hours of prying and hammering on it with a 3-lb plastic dead-blow mallet to finally get the damned thing off so I cold file the alignment tabs for proper indexing of the top rail. I'm not looking forward to having to do that again, especially since I have this nice paint job on it now.
Ian
Notorious member
Yeahhhh, I'm sort of stuck with this one. I built it on an 80% lower. The upper with one extra magazine and mag well adapter cost me $1,100. I could tear it down and stick a .458 SOCOM barrel and gas system on it (ejection port is already enlarged), but I'd be basically throwing away everything except a $90 assembled upper, $150 hand guard, and $70 bolt carrier. I'd then have to buy a new barrel, gas block, gas tube, bolt head, loading dies, and brass. Or I could just shoot plated or jacketed ammo. Aside from totally ruining the whole object of having a .45 ACP carbine (cheap shooting), that's the only thing that makes sense to do at this point.
F
freebullet
Guest
Bummer!
It almost sounds like the barrel could be twisted a bit from the overzealous tightening.
How much is a new barrel?
It almost sounds like the barrel could be twisted a bit from the overzealous tightening.
How much is a new barrel?
Ian
Notorious member
I probably won't be able to get another barrel, the manufacturer was at one point going to make parts available for DIY people, but changed his mind due to the "difficulty in getting them to run". I would much rather have built this thing from scratch as much reworking as I've had to do already. I wanted to buy a spare bolt head and the manufacturer agreed to sell me one in one of our several phone conversations, then later reniged. I'd have to have a barrel custom-made for it with a standard AR barrel extension, and I'd get it made with the larger gas block diameter and leave it .936" all the way to the muzzle.
All that said, the thing is still one of the most fun guns I have to shoot, I just wish the barrel was better for cast bullets.
All that said, the thing is still one of the most fun guns I have to shoot, I just wish the barrel was better for cast bullets.
Ian
Notorious member
I do think the muzzle is crushed a little, there's an odd pattern to the fouling in the last half-inch of barrel. Why that doesn't seem to affect the way jacketed or plated bullets group is beyond me. I'm also inclined to think the whole barrel got unscrewed like Freebullet mentioned. L1A1 Rocker has kindly offered to cut it off and re-thread it, provided I can get the barrel off the action and figure out how to shorten it legally (would have to pin a flash hider or other extension in place). Or, since I'm married to it anyway, I could SBR the thing and chop about six inches off of it.
