I have a couple of VZ24's and would like to make one into a 6.5 Bob Imp. and would like to hear from someone that has one or an opinion on doing such a thing.

Are you saying you want a 6.5X257 Improved (40 degree)?
Should be a performer. 6.5X257 does well, but not what the improved chambering will. Im guessing 150-200 fps over my standard. My accuracy load is 2700 and change with 129 Hornady interlocks, that and the old round nose 129s work for me so I don't really try anything else.
LouisB

Nothing worse than having some actions lying around looking for that special barrel!


[ 11-24-2002, 19:49: Message edited by: TCLouis ]

I have one, a Sako action with a 23in. Douglas 1-91/2 twist. My rifle weighs 71/2lbs with a 6X Lyman scope. With it I have killed deer and antelope. The two bullets I shot game with are the old 120gr. Nosler solid base, and the 140gr. Speer Hot Core. I have never recovered a 140Speer as they have always shot completely though the animal.
With the 100gr. bullet you can expect 3300fps.
With the 120gr. bullets you can expect 3100+ fps.
With the 140gr. bullets you can expect 28-2900fps.
Another name this wildcat goes by is the 260AAR---
All Around Rifle.

The 260 AAR should be a fine cartridge, but have you thought about the 6.5x55 ackley improved ?
With the long throat of the 6.5x55, you can seat the bullets out a long way which should give you just about the same case volume of the 260 AAR with the heaver bullets and you can shoot factory 6.5x55 cartridges in it to form your cases.
Just another option to think about.

Sorry, I am a little off topic, but I see that the 6.5x55 Swede, IMPROVED was mentioned. I have been in search of data on this chambering, and have found nothing. Well at least nothing to determine if it is a good or bad thing anyhow. Dale M Do you have any thing you could share with us about this cartridge? I am getting ready to build four rifles in the 6.5x55, and wished to make at least one in the improved configuration. Going to use the .465 shoulder instead of the .455.

I found a post that has mentioned Mr. P.O. Ackley stated that you couldn�t improve on this cartridge. Don�t ask what that means, there was no explanation in this persons post.

Thanks; hope some one has some good info...

Thanks.

I have a 6.5-257 roberts imp that was built on an arisaka action back in the mid 50's for my father-in-law. It has a 20" douglas barrel with a muzzle brake. I chronographed it at 2800+ fps with IMR4831 and 120 gr NoslerBT. The guy who made it for him swore it would get 3000fps with that load and 120gr bullets. I don't think he lied, he was just optimistic. Go with a longer barrel and performance will increase. It is devestating on deer size game (just like all my 6.5's with 120gr bullets). I currently own 5 rifles in 6.5mm. 6.5-284, 6.5x55 (ruger and surplus) 6.5-257 roberts imp. and a 6.5-06. The 6.5-284 will out perform the roberts imp as there is about 5 gr more capacity. Same with the 6.5-06. But at the same time the swede will load right up to 3000 fps with the right powder. I really enjoy fireforming cases for the roberts imp but dies are expensive.

On a side note. Since the 257 roberts is based on the 7x57 Mauser. And the 7X57 is based on the 8X57 mauser. And there is a european round based on the 8X57 called the 6.5X57 Mauser. Wouldn't it stand to reason that what you are trying to build is actually a 6.5X57 Mauser Improved? Don't mind me I'm just making conversation here.

good luck

What ever you want to call it- 260AAR or 6.5X257IMP it's a fine round. In Ackley's manual he refers to it as the 260AAR. The late Warren Page, gun writer of Field&Stream had quite an write up on it back in the 60s. I came across it several years ago and that's why I built one, and my rifle is so marked.
Page claimed slightly more velocity then I've been able to get and his gun had an inch shorter barrel then mine.
As with most of the Ackleys improved rounds the cases never seemed to get sticky in the chamber. But, when the the primer pockets open up after 2 firings things are too hot. The velocities I stated are with case life from 6-8 reloads.
Pete

PS. One of the first guys(so he claims) who chambered a 6.5 Jap to 257Rob. case call it the 6.5 Spence Special (that was the gunsmith's name). It is also listed in Ackely's handbook under that name. The 6.5X57 is a Euro thing and Ackley must not have like that name.

I haven't found much on the 6.5X57 but that was my first choice. The problem I had with it as long as it is just a 7 or 8X57 necked down was there was more powder there than I wanted to burn where as the 260 and 6.5X55 didn't have quite enough. I did find a listing of the 6.5BOB imp 40* and it really fit the bill as far as speed and case volumn. The 6.5X55 imp 40* would probably be a very close 2nd though but don't have any listing at this time of what the speed of it is or case volumn.

I did a little surfing and found little on the 260AAR other than a few reamer places that sell the reamer and they also list the 6.5X55 Arch. Imp. Don't know what that is weather it is the BJ one or the other 6.5X55 Imp. with the smaller sholder. On a side note the good thing about the 260AAR is that is alot easyer to stamp on the side of the barrel than 6.5 Roberts 40* Imp..