Odd problem. I have a .419 barrel. I am having difficulty resizing .423 bullets. I am working on that one. .419 bullets are not easy to find. I am considering going with a .416 bullet. After standard resizing, using a 416 die to resize the neck. Has anyone got any experience with using an undersized bullet? I question whether the bullet will stabilize well but only shooting will tell. Load warm? Less friction? Treat it as extra freebore? Thanks, "D"

Are you measuring grooves or lands?

In smaller calibers, such as 7.62x54R, that's commonplace. I have a Mosin-Nagant M91/30 with .312" groove diameter. (.3005" bore diameter.) It shoots standard surplus bullets of .310" diameter about as well as I can aim and hold with open sights, which isn't saying much. Quite a few folks report acceptable accuracy with .308" bullets in these.



I'd suggest trying it to see for yourself how well it shoots.

I loaded up some rounds for an old 1895 winchester once that was chambered in 303brit.(barrel .311") neck sizing the cases with a 308 Win die and loaded the 165gr corlock. I never shot any groups on paper but hitting 4" clay targets at 100 yards became regular with the open sights. I've yet to load any since then because nobody could tell me for sure if it was an OK practice. I was worried about the hot gases blowing by the bullet and damaging the throat area. I've never really thought about it since but am planning on using the rifle on a deer hunting trip this fall so I might like to try again if any one can help.

I am measuring the full depth of groove. I slugged the barrel and it comes out to .419 as best I can tell. Some say they are supposed to be .418 and maybe my slugging or measuring is off a thou. On further measuring it looks like the lands are .411. That should catch a .416 bullet nicely I should think. Any other experience out there? "D"

NB, I've seen references on the Mosin discussion boards to rapid bore wear from gas blowby with .308" bullets, but no documentation. I'd think that since typical factory bores on those things have larger groove diameters than the factory bullets, it'd already be happening if it were a problem. Maybe on soft old blackpowder barrels it'd be more of a concern. I doubt you'd have trouble with .308" bullets in a .303, especially for limited hunting use, but there are commercial .311" jacketed hunting bullets available.

If the bore is about .411, there is a solution offered by the writer Seyfried that will let you "expand" the bullet to any groove diameter you need to seal the barrel. He has used paper patched, metal jacketed bullets of bore diameter in several of his guns and reports good success. It's tedious, but patching standard .411 bullets should do.

If you can get 416's to shoot well enough I wouldn't worry about it. The biggest pain may be a build-up of copper just forward of the throat from initial blow-by. Avoid mono-metal bullets like the plague.
You didn't mention the cartridge; peak pressure may have a lot to do about how fast the bullet obdurates to fill the grooves. If its a low pressure turn-of-the-century round it may never do it. Nosler Partitions may obdurate a little better with the exposed lead in the base.
If all else fails, you can bump .416 lead core bullets up to .419 in a strong press like a Corbin bullet swaging press easier than reducing .423s.

It is a .404 jeffrey. I am loading some monometal bullets as well as SAF. I am using some barnes X and North fork. We will see what they do. I can't for the life of me see the problem with monometals particularly the Barnes. Barnes is copper and is famous for copper plating. I assume that is from the softer copper deforming. I would assume also that that property would help to fill in the gaps and provide a seal. I will let all know how my experiments go provided I don't blow myself up. "D"

I am planning to use 93 grains of H4831. Not a hot load but it is a nearly full case. It gives about 2250 using 320 gr .418 GS custom HV monometal bullets. If anyone can think of danger in this load say so now cause I plan to go to the range at the earliest possible convenience. "D"

Paper patching isn't really all that tedious but I don't think you have enough room to work with. .003" won't allow you to wrap but one time with .0015" tracing or pattern paper and you need at least two wraps. My suggestion would be to ask Corbin if they make a bump die that will allow use to increase the diameter of your bullets(.416). As I recall they are simple and fairly cheap. Provide your own mallet. I do not know if they will work on jacketed bullets and would be certain they won't on monolithic solids. As an alternative you may want to consider hard alloy cast bullets, or softer alloy for paper patch if you're shooting thin skinned things.

Remember, I said a .411 bullet could be used. These are available from Woodleigh and others. This leaves .008 to fill, and he'll need 2 wraps of approx. .0025 paper. I'm away from my notebook just now, so I can't say for certain what the recommended allowance for shrinkage is. It seems to me bumping up a .416 would be quicker than patching a .411, though.

The problem withe the copper build-up is that it never quits. Copper is "sticky" against more copper; the ultimate in galling. It doesn't mean they absolutely won't shoot at some point but it will only perform for a relatively few shots before you get past benefit curve and into the detrimental curve.
Then, on the other hand yours could be the exception that makes it a rule. Good luck with the trials.

True. I've not been fond of patching jacketed bullets but that would be my problem.

no answers?

I once purchased a whole mess of .303 bullets that had been pulled from military surplus cartridges. I had difficulty getting some of them to 'grip' in the neck, so out came the micrometer....

I found a variation of between .307 and .312" Anything .308 and smaller was set aside for use in my Garand, and those larger than .308 seemed to hold well in my .303 case necks. These bullets were used for plinking, but they worked well.

The point is that the FACTORY .303 ammo had such a wide tolerance. Nobody seemed to complain about the factory stuff, and most of the .303's which thrived on this stuff (WWII??) are still bringing home the bacon today.

I would be hesitant to size (swage) a jacketed .423 hunting bullet down to .419 for reasons of integrity, but there is no reason why you couldn't do this with cast bullets. Lee sells a handy (cheap) die for this purpose - I'm sure they could make one up in .419. Actually, for cast bullets .420 or .421 may be the way to go.

An expensive option is to get somebody to turn .419 monometal bullets for you. The 'grip' issue on the necks could be resolved by polishing down the neck expanding mandrel on your sizing die. (Saves you the extra step of using a .416 die on the necks, which might affect concentricity). If you're prepared to go to these lengths, you would have fixed your problem, but only for your rifle.

While I've never tried it myself, I thought it a clever solution. How did it work for you? It seems it would reduce fouling. It might also allow for a bit more fps since you end up with a lubed bullet, which starts easier. This would be more so with the harder bullets like the X. I'm not sure if the lube would make for more or less consistent fps; I see it going either way.

Asdf, I went to the range yesterday. They shot at reasonable velocities. Swift A-frame 400 gr was right at 2300 fps, North Fork 325's were at about 2400 fps, and Barnes X 300 gr were at 2400 also. No indications of pressure. Accuracy was not great. About 3 inch group, open sights 50 yards. Looks like there might be a better way to skin this cat. I will look into .418 bullets and if no dice may look to a rebarrel. Thanks to everyone. "D"

Well, actually D Hunter, I was hoping to hear from DigitalDan...

If you wish to try the paper patch with .411 bullets instead, let me know, and I'll P.M. you a copy of my notes on the subject, taken from book and magazine articles. Again, I cannot vouch for the method.

asdf I might try that too, but right now I have a source of bullets to fit. They may take some time to get and load for but I will try this first. There is a limit to how much energy on wants to put into a given project. It may be that the barrel won't shoot any bullets any better than these groups. Another option is just to rebarrel it. We will see. Thanks all. "D"