I am VERY ignorant on these subjects, so please bear with me on the questions that I have here. Also, I would like to make a suggestion at the end of this post.
I have read many post concerning "long throats" in the handi rifle. An example of this is the .357 mag barrels. First question is, what negative effect does a long throat have on a rifle?
Then I read that people rechanmer the .357 mag to .357 max. This I assume gives a proper throat. Yet, I still read that when they shoot .38 special and .357 mag out of the newly rechambered barrels, the accuracy of the .38's and .357 mags is good. I thought that rechambering for .357 max would have made the throat longer and therefore made the .38 and .357 mag shoot worse. In other words, wouldn't the rechamber make the long throat worse for the .38 and .357 mag? (Remember I am speaking from ignorance here.)
The third question is, what calibers suffer from the "long throat" problem?
Now for my suggestion. I know this would be a bit of work for someone, but it might be a nice sticky. Perhaps a list can be made of all the barrels that can be safely rechambered to something else. First on the list would be .357 mag to .357 max. I am sure there are many others as I have read posts here and there. It would be nice to consolidate all that information. (There is even a post just a couple of post down from this one concerning a rechamber.) The reason for this is that maybe someone wants a bull barrelled Handi in 30-06. Can the .308 bull barrel be rechambered for 30-06? It would be nice to have this info available.
Thanks for your answers.
Matt
45/70 Handi
.270 Handi
Way back when...I used to think that the long throats were a deterent to good accuracy...I always thought you had to seat the bullet out to .001"-.005" from the lands to achieve the best accuracy...after all...all those gun writes couldn't be wrong...now could they???..If fact...they were...when it comes to our Handi-rifles. For example...I had a bull barreled 308 Survivor...and I couldn't even get close to the lands with a 190 SMK bullet...and it took the 200 grainer to get it there...but it would shoot the 168 grain Federal Match ammo to 1/2" groups and the cheap Winchester Power Points even smaller.I had over .040" bullet jump with both of these...
Fred is absolutly correct...it isn't the amount of bullet jump you have...if that were the case...no Weatherby Mag rifle would ever shoot good...and that isn't the case at all with them...nor would some of my revolvers...they have even more bullet jump...it is the shape and contour of the Leade that makes or breaks accuracy.Some rifles have a long taper...but perfectly concentric...others shave a short leade and but very evenly cut...those that are perfectly cut and are longer...will produce the best accuracy but lower velocity...and those that are shorter but still cut correctly will give good accuracy but higher velocity.The problem comes when the leade is cut out of round by the reamer...accuracy will never be very good when this happens.
As to making a sticky with which barrels would make suitable conversions...there are just to-many possiblities...RCBS has a 1-1/2" thick book out on the subject..you can however check the size of the parent case against the one your considering...the new one has to either utilize the existing case...or the chamber must clean it up enough for it's useage...you can rebore to another cartridge...just like I did with the 338-06 by taking a 25-06 barrel and redoing the throat and rifling...As you can see,when it comes to rechambering...and re-boring...then your increasing the amount of choices at your disposal...The main point to remember about our little rifles...they can sustain the 270 at 65,000 PSI..If what you wanting to rechamber to...will do this amount or less with a 30-06 case head...then it will work...and if your wanting a larger case head...then you'll need the mathmatical formula to figure case head size difference with the back thrust...the larger the case head...the
less pressure you can have...and this is due to the design of the action...and the quality of the steeel being used...
To answer your question...no...a 308 Handi bull cannot be converted to a 30-06 due to the differences of the case size at the shoulder...the 308 has less taper than that of the 30-06...it's .454" at the shoulder...and the 30-06 is .441".....there are cartridges that could be made to work...like an A.I. style...but then your going down a all together differnt path with quite a differnt set of rules to deal with .....Each rifle is different...and this is where having a accurate chamber cast comes into to play...this is so you can actually see and measure what your chamber is...to make a better decision prior to having any work done....there wouldn't be much use in doing a Ackly improved cartridge if you had a very long throat to begin with...you would only be increase your bullet jump...and your velocities would suffer greatly...not to mention one of the main benifits would be to utilize the standard parent case in it and then fireforming it when fired...since your velocity is going to be diminished with a normal throat...having a longer throat will only make if suffer more....and we haven't even touch on other problems that will occur namely barrel lock up...since the recomended starting point is
+ .004" of positive headspace for adiquate forming of the case to the chamber...and the best lock up is .002" or smaller for accuracy...so getting it closed and locked up properly will be an issue if not extreamly carefull when having it cut for one...unless of course your starting out with a headspace issue to begin with and plan on fireforming your loads not from shooting the parent cartridge...but as a true wildcat type by other means.....as you see...it can get pretty involved with all the different choices and variables...and that would be just a bit much for a sticky..
Mac
