I have a friend who is interested in a period 240 H&H nitro rimless rifle that has been deemed unsuitable for modern ammunition by virtue of a tight bore (a not uncommon problem with early examples)

Apparently the 'old' kynoch ammunition is much softer and is safe but modern bullets are harder and unsafe. Bore tightness might be up to 5thou undersize (allthough I think this is extreme)

Is it feasable to swage modern 243 bullets to the undersize bore and if so who makes such dies? Are they for one specific bullet only or do they work on the shank only and hence all 243 bullets?

It would be a lovely rifle for the cash allthough of little value per se due to this.

Hey 1894, I'd recommend you "Slug-the-Barrel" to determine the actual I.D. You should be able to get a GunSmith to do it for little cost.

Or, get a few Lead Slugs of approximately 0.243". Select one and roll it between some steel plates to "slightly" reduce the diameter to say 0.240". Then oil the Bore, oil the slug and drive it through with a Brass Rod.

If the "Barrel Grooves"(now the high part) are square and sharp, measure to O.D. to determine the Bore I.D.

If they are not square and sharp, roll another slug so it is slightly larger and re-slug.

Once this is done, then you all will know whether the cost of buying Bullet Forming Dies from Corbin is necessary, if you just want to go with Sized Lead Bullets, or if you can use regular 0.243" jacketed bullets.

Of course, a lot depends on how "tight" the bore is. Do you have an empty case that has been fired in this gun? The .244 H&H (is this what you have?)is supposed to fire .244" bullets. If so, take it and see if you can get a new .243" bullet to drop freely into the case through the expanded neck. If so, you could get bullets like standard Sierras, Hornadys, or Speers up to .003" or so oversize(compared to your groove diameter)to work without having to swage them down before firing, provided you use a slow powder (IMR 4350 or slower). Because modern slow powders produce their peak pressures AFTER the bullet has travelled four or five inches down the bore, pressure problems generally occur only if the cartridge case does not freely release the bullet when the round is fired, and not because an oversize bullet is being forced into the bore. I have known people who had serious pressure problems firing .243 Winchester cartridges cartridges they made from .308 brass because they did not reduce the thickness of the case neck sufficiently after necking down the case.

Some very strange things have occurred in regard to shooting oversize bullets. Back in the 1950's, there was an instance in which a fellow rechambered his 6.5mm Japanese Arisaka rifle for the .30/'06 cartridge. His new chamber had a throat big enough for the '06 case to fully release the .30 caliber bullet, which entered the unaltered 6.5mm bore, and was swaged down to 6.5mm. This was reported in the American Rifleman, to whom the owner had sent the rifle for testing. This gun was safe to fire, no excessive pressures occurred due to the bullet being reduced from .308" to .267" upon firing. Of course, you need to determine the exact groove diameter of your rifle's barrel. My Nonte Cartridege conversion book shows bullet diameter of .245" for both the .240 Rimless Nitro Express and the .240 Flanged Nitro Express. It also shows .249" bullets for the 242 Rimless Nitro and .253 for the .246 Purdey Flanged. If yours is the H&H, as mentioned above, then the groove dia. should be .244".

[ 02-28-2003, 20:52: Message edited by: eldeguello ]

I think that bullets up to .003" greater than bore size would perform reasonably well and would require only a small adjustment in powder charge. As an example, many 7.62 x 39's are now being built with .308 barrels as opposed to the standard .311 barrel, but they fire standard .311 military loads without a problem.

If the bore (groove) slugs less than .240", then a swaging die can reduce a jacketed bullet up to about .005" or maybe a little more without damaging its structural integrety.

Once you establish the actual size of your barrel, you can get a ring die, and run some .243 bullets through it to make the bullets you need.

The Corbins - Richard at rceco.com and Dave at Corbins.com, as well as Z Hat at z-hat.com make these, and they can be had at reasonable prices, and can be made to work in a good reloading press.

They're OK if you're reducing 6 thou or less. I think Z Hat's are the cheapest.