Twist Rate of an early Model 760 Barrel???

[Lawful Larry]

Okay, I took my Remington model 760 to the range the other day and put some reloads down range. The 165 gr. Sierra Gamekings didn't do as well as the 180 grs. Speer spitzer.  Does any one know what the twist rate is for a 760 that was made in 1960?

This is a target using the 180gr bullets. The 165 gr bullets grouped about three times this one:



I had one guy tell me his 1980 model 760 barrel was listed as 1 in 10".  This is probably not the same barrel since it is a twenty year difference.  I think it may be a 1 in 12", but am not sure.  Bottom line if I can't get an answer I will slug the barrel.  

I tried to contact Remington, but their system is totally automated.  No real people to talk to about this question.

[ricciardelli]

I have no idea why you want to slug your barrel to find twist rate.

All you have to do is place a couple of patches on a button tipped cleaning rod.  

Insert the rod a couple of inches into the barrel.

Mark the cleaning rod with a Sharpie.

Index the cleaning rod, and insert it until the index mark comes back to the same position.

Mark the rod again with a Sharpie.

Removed the rod and measure the distance between the two marks.

That is your twist rate.

[Questor]

Why not take the guess work out of it. It's easy to do.

The shaft on your cleaning rod probably rotates when you push the handle, most cleaning rods are set up that way now.

1) Put a patch on your cleaning rod.
2) Insert the rod into the bore and engage the patch in the rifling.
3) Mark the rod with this starting point
4) About 18" toward the handle, put an index mark on the rod, a dot that will indicate a full turn of the rod.
5) Push the rod in until the index mark indicates that a full turn of the rod is completed.
6) Mark the rod with this ending point.
7) Remove the rod and measure the distance between the start and end points.  There's your answer.
8) Repeat the procedure for confidence.

It's harder to describe than to do.  Takes about 2 minutes.

[ricciardelli]

There's an ECHO...Echo...echo...in here...

 

[Lawful Larry]

I have no idea why you want to slug your barrel to find twist rate.

Duh!!!   :eek:

You are completely right.  I guess I was thinking of something else.  I will try this method and see what I get.  

Thanks guys.      

[Larry Gibson]

Remington has always used 1-10" twist barrels for the 30-06.  However it always pays to measure your own. I have found the twists to vary as much as 1"+/- from the advertised twist. Just the way the make cut or button rifled barrels.  

I have gotten very good accuracy with the 165 GKs out of 1-10, 1-11 and 1-12" barrels. Your rifle either just doesn't like the GKs or the load (not mentioned). It may also be that the crown needs touching up as the Speer is a FB and the GK a BT. I've found barrels with damaged or not quite square crowns to shoot the FBs better than the BTs.

Larry Gibson

[Larry Gibson]

Remington has always used 1-10" twist barrels for the 30-06.  However it always pays to measure your own. I have found the twists to vary as much as 1"+/- from the advertised twist. Just the way the make cut or button rifled barrels.  

I have gotten very good accuracy with the 165 GKs out of 1-10, 1-11 and 1-12" barrels. Your rifle either just doesn't like the GKs or the load (not mentioned). It may also be that the crown needs touching up as the Speer is a FB and the GK a BT. I've found barrels with damaged or not quite square crowns to shoot the FBs better than the BTs.

Larry Gibson

[Questor]

Why do you want the twist rate? I only checked the twist rate once in a gun and that was because it was keyholing bullets.  It turned out that I needed to use shorter bullets.

[Lawful Larry]

Why do you want the twist rate? I only checked the twist rate once in a gun and that was because it was keyholing bullets.  It turned out that I needed to use shorter bullets.

Just thought that the rate may be why the bullets were shooting different.  I know that it is a big difference for the .223 in different rifles and different twist rates with different weight bullets.  I thought it may be the same in this rifle.  

But I will check it tomorrow and let everyone know the results.  

[Siskiyou]

Remington used a 1in 10 twist.  

Being the M760 is an old rifle I would do a close check for copper fouling.