I just bought a very nice, absolutely mint VZ-24 Lightweight Sporter for my Missus and was told it is in 6.5x55 Swedish. However the barrel is not marked. I used an interior micrometer and got the measurements .247, .245, .251, .244 and .248, none came close to .255 to .256 of a 6.5mm! I tried to chamber a 6MM Rem and it fed and chambered perfectly but the bullet went into the muzzle all the way to the case mouth, while the 6.5 fed and failed to chamber and the bullet stopped at approx. the bullet's ogive. It is in great condition, however when I tried to chamber a round of 6.5 it felt like it went all the way to battery but the bolt handle would not begin to close any, to chamber the round. I also needed a rubber mallet to drive the bolt handle back to extract the round. My question is this; Is this likely to be a short chamber problem, headspace, extractor or the wrong 6.5 cartridge, problem? Suggestions, solutions, opinions, any offered will be greatly appreciated! Thanks in Advance
It is quite dangerous trying rounds in unknown chambers. A chamber cast and bore slug is the proper way to go about identifying… relatively easy to do with cerrosafe from Brownells.
Steve: I agree but I wanted to try and at least narrow down what I might have. I have measured again and came up with a repeatable .251 as the bore so I believe it is a 25 CALIBER (.250), A 25/06 WOULD HAVE ALLOWED A 6.5X55 TO CHAMBER completely A 257 ROBERTS would not. A .250 Savage has a bore dimeter the same and also would have failed to chamber. So tomorrow I am going to feed function test a 257R and a 250S.
Jerry,
"Europeans often label .25 caliber cartridges (.250" bore and .256-.257" groove diameter) "6.5mm," which is actually .26 caliber (.256" bore and .264" groove diameter). The metric nomenclature for the .25-35 WCF, which uses standard .25 caliber (.257") bullets, is 6.5x52R. True 6.5mm cartridges, such as the 6.5x55 SE, use .264" bullets." from the site
Cartridge Names This sounds like what you are running into. As SDH suggested, cast the chamber and throat. You could also drive a piece of buckshot into the bore and mike it. I use a wooden dowel for this when necessary and only drive it deep enough to get a swaged cylinder and then back out with it. Buy some cerrosafe (sp?) and cast it. Perhaps a 250 Savage or 257 Roberts since the 57mm cases are chambering, I lean towards 257 R.
Thaine
Thaine: I agree completely with your assessment. I didn't know, I or you were so smart! My wife just told me, it's you! Thanks Good Buddy Jerry
If you've never used Cerrosafe, just remember that there is a somewhat narrow window of time in which to measure your chamber casting. If you wait too long, your measurements won't be accurate because the Cerrosafe casting continues to shrink as it cools.
Another alternative, since you say a 6m/m Rem. seems to be a very close fit, would be to load a 6 m/m Rem. case with a fire-forming load. Since you don't know exactly what you have, I'd stick with one that used a relatively fast burning powder topped with dacron or Cream of Wheat filler, rather than firing a round loaded with a .243 diameter bullet. Of course, you'd still have to slug the bore to get a true land and groove measurement. The fire-formed case could also be used to send to RCBS etc. to have reloading dies made if it turned out to be a wildcat. It does sound like you have a .257 Roberts, but chamber reamer dimensions did vary somewhat before the round was standardized.
Better safe than sorry. Years ago, I was totally blind for about 30 minutes after I had a complete head separation with a sporterized VZ-24 in .22-250. It felt like getting punched in both eyes by Mike Tyson. The problem was old brittle brass from a friend's gun with a minimum chamber, fired in my near maximum length chambered gun. No problems with the same load and new brass. Thank God for Paul Mauser's redesigned bolt shroud in the 98 which deflected gasses above, below, and between the shooter's eyes. I had the powder burns and brass particles to prove it. Wear those shooting glasses or better yet, do any experimentation with the gun tied down to an old tire and a long string to pull the trigger. A large oak tree between you and the gun may be prudent.
Wouldn't,,,or shouldn't,,the 6.5 Swedish round fail to chamber in any chamber with a standard '06 size base diameter (.471 (?)
I thought the Swedish round was a bit larger in diameter at the base than all those other common base rounds.
It's a guessing game at best this way. Perhaps it's a wildcat round of some sort too.
Way too many possibilitys
Get the cerrosafe or even do a quick cast with wax or epoxy while you wait if you have to order some.
That'll give you something to look at and give you an idea of the chamber shape, length, shoulder angle, ect.
Anything marked on the bottom of the bbl under the wood?
KUTTER: By GOD your right, I forgot the Swede is .480 at the base! Already checked, nothing on the barrel.
I bought a beautiful, Niedner, G&H, Shelhamer, Kornbrath 1903 in .257R only to find out it had been "improved". I really look forward to sharing this one with all of you. I am going to great lengths with this one to make it right. I agree with most of what has been said here, use Cerosafe first. I would not fire anything in the rifle until. Just to easy to get a precise cast and then you will know what you have. It seems like a lot of trouble but is very simple to do. I keep a couple of extras just in case.
Kutter,
The original 6.5x55 is larger, but my brother bought American made commercial cases for his, and they had 06 headsize(I guess to avoid new tooling).It worked fine, after expanding to chamber size.So,new American 6.5x55 ammo may almost chamber in 257 chamber.BTW Cerrosafe does shrink, at first, but after some time it expands to original dia.This drill points out the importance of marking the caliber on the barrel.It is easier to make a chambercast if you pull the barrel first( add witness mark if not one already).
Mike
If you are in the market for CerroSafe go to Rotometals, you get more than twice the amount for less money than Brownels. Also when you click on the product a chart comes up showing the material changes based on the time of the cast being taken.
RotoMetals.com
J.Louis
Chamber cast is cheap insurance.
Bretheren: I believe I have narrowed it down to where I can fireform the correct cartridge with a small charge and a cream of wheat w/seal. Please see if my madness checks out. The bore diameter measures .250 when a proper micrometer is used. The 6.5x55 and now the 25/06 Rem. WILL NOT CHAMBER. The 250 Savage WILL CHAMBER. The .257 Roberts WILL CHAMBER, as well. Ergo... If the .257 Roberts CHAMBERS IT CANNOT BE A .250 Savage, as the .257 Roberts is TOO LARGE to chamber in a .250 Savage chamber due to the shoulder diameter being .414 on the .250 Savage and .430 on the .257 Roberts. Therefore since the bore is .25 caliber, and the chamber is too small to be a 25-06 and large enough to accommodate a .257 Roberts, by process of elimination it has to be a. 257 Roberts and even if it is a .257R ACKLEY IMPROVED, firing factory cartridges, merely fireforms them to an AI. The other three .25 caliber cartridges 25/20 and 25/35 and .25 WSSM don't enter into the equation for obvious reasons. What say you to this theory?
6 mm Remington and .257 Roberts has same parent case i.e. 7x57 so it seems that yours rifle is either .257 Roberts or .257 Roberts AI.
A fireforming load in any case you can chamber,won't build up enough pressure to hurt your rifle.Have at it.
Mike
I suggested fireforming a 6 m/m Rem case several days ago. I expect it will blow out to .257 Roberts dimensions, or some improved version thereof. Use new or annealed brass so it fills out nicely without any splits. Of course, using .257 brass for your fireform load will work too. I suggested 6 m/m because it sounded like you already had that cartridge on hand.
The .257 Roberts is a great cartridge for your wife to use, so hopefully you'll get the standardized version that is available in off-the-shelf reloading dies. Good luck.
THANKS EVERYONE! LAST QUESTION: Does everyone agree, that my Process of Elimination resulting in the .257 Roberts, being the PROBALE/LIKELY cartridge is a sound one? Jerry