Anyone know the twist on a BLR in .257 roberts?

[ncsurveyor]

Anyone know the twist on a BLR in .257 roberts?

[quickdtoo]

I looked for ya, the only thing I found was the A-bolt II 257R is 1:9½". It's easy to check if you have a cleaning rod with a ball bearing handle, or one that can rotate freely to follow the rifling, use a tight patched jag, start the jag in the bore, mark the rod at the muzzle and place a flag of tape around the rod close to the handle so you see when the rod had turned 180º as you push the jag thru the bore, mark the rod again at the muzzle, then withdraw the rod and measure between the two marks, double it for the twist rate. 

Tim

http://www.exteriorballistics.com/reference/pdf/Twist%20Tables_Rifle.pdf

[ncsurveyor]

Thanks quick,

I saw that same page, but didn't know if it applied to the Bob.  All the other literature I found refered to most factory bob chamberings were 1 in 10.

Not that a ½inch makes that much of a difference, but it may persuade me to get the 117 or 120 gr as opposed to the 100's for reloading as a first attempt.

The rifle is not yet in my possession, it is making the slow trek from the west coast.

[quickdtoo]

Since it was on the west coast, you should have let me check it out for a while for ya.....say thru deer season, I could have that twist rate figured out by then!!!

Tim

[ncsurveyor]

Since it was on the west coast, you should have let me check it out for a while for ya.....say thru deer season, I could have that twist rate figured out by then!!!

Tim

I have to wear a bib now as it is, because I'm drooling over the pictures.

It was a toss up which I would get to first, the Bob, or a 25 souper, I was planning to build off a savage action.  But considering a low availability of economical Bob barrels, I was building up the funds for an aftermarket barrel either way.

Then I saw this.

Considering how much I love levers, this one was a no brainer.

Unfortunately, your going to have to wait for me to clean it, caress it , sleep with it, take it out to dinner and rack it about 17 gazillion times before the opportunity for you to check the twist throughout an entire season presents itself. 

I do have a Handi rifle you can borrow.  Do you have any of those?   

[quickdtoo]

A few handis, but I do have a .308win M81 BLR too.

Tim

[pastorp]

NCSurveyor, Nice rifles the Browning BLRs. I have one in 257bob and a few other calibers. They are favorites of mine. I've killed more game with a belgium blr in 308 than any other single rifle I own. Regards, Byron

[ncsurveyor]

picked it up yesterday.  I can see why they're likeable.  Great addition to my lever collection, I think it will do nicely.

Byron, my go to gun is a Savage 99 in 308.  If I can get some ULD bullets to group in this Bob, it may take its place.

Need to figure if its 9.5" or 10 twist.  9.5 I may push a 140 Wildcat ULD RBBT bullet, 10 twist I may have to stop at 120's or 125's.

Jeff

[ncsurveyor]

My cleaning rod bearing was a little tight, i.e it didn't spin freely.

But I managed to get seven measurements:
9.25
9.5
9.75
9.5
9.25
10
10.25

Considering the rod is more likely to move in and out without spinning I would err on the lower side. 
Even a 10 twist, a half inch of lateral movement should rotate 18 degrees, I'm sure I can judge that OK.

What I'm trying to say, I'm pretty sure its a 9.5 twist.

Now, see my next post........