Any one tried a 307 win in a contender.Can a 30-30 be rechambered to 307 win ? I was reading that the 307 and 30-30 AI were real close in ballistics.

The 307 Win. operates at, (52,000 C.U.P.), too high of a pressure for contender frames. One of T/C's first chamberings for the contender some 25+ years ago was the 300 Savage which operates at 46,000 C.U.P. Very similiar in case capacity and dimensions to the 307 Win. Unfortunately, too many people tried to make the 300 Savage into a 308 Win and stretched their frames.

I have a gunsmith who will chamber a 307 Winchester Improved and I plan on using 300 Savage data for the cartridge to keep the pressure limits on the safe side. The 307 Win brass is thicker thus will stretch less. Also by taking the taper out of the case from rechambering to an improved case, the case grabs the sidewalls of the chamber instead of back thrusting against the receiver.

The answer to your second question. No a 30-30 barrel can't be rechambered to a 307 Winchester because a 30-30 case is slightly longer and won't allow a clean chamber cut. If you could find an older 6 groove 30 Herrett barrel this would be ideal for rechambering. The newer T/C barrels are 8 groove and cause higher chamber pressures with the same load in a 6 groove barrel. More friction because of more contact with the bore.

Sorry for such a long winded answer.

7-30 Waters

I have a 6.5JDJ#2 in a Contender that is a 307 necked down to a 6.5 and shoulder blown out. Neat round. Info came from JD and is to be safe. He also makes a 7mmJDJ#2. The key word here is safe pressure's!!

7-30
Thanks for info.I will just rechamber to 30-30 AI instead.
Thanks

7-30
I read your previous post about 307 win improved.Why would the 307 improved work but not the 307?

If you remember from my post I stated the 307 Win operates at 52,000 C.U.P. This pressure is too much for a contender frame. The reason I chose a 307 Win Improved chambering is strictly to utilize the thicker stronger 307 Win brass rather than go with a chambering in 300 Savage. I want a case with a rim. I could have a 300 Savage Improved using the 307 Win. case and trim it to length. Since the case dimensions for both the 300 Savage and the 307 Win are close to being the same, I can use 300 Savage data in place of the 307 Win data and keep the pressures at 46,000 C.U.P. The improved design will grab the chamber walls in the barrel instead of back thrusting into the frame. The 307 Improved design also prevents the cases from stretching as much as the standard 307 Win. Case life is extended. Thus less trimming and case prep time and more shooting time.

A good web site to check out is www.bellmtcs.com

Mike Bellm can explain why improved cases are better.

Your choice of a 30-30 AI will accomplish the same thing as I am with the 307 Improved. I would probably rechamber to a 30-30 AI also but the barrel I am having rechambered won't allow for a 30-30 AI. Chamber is too wide already for 30-30 AI. Need a fatter cartridge like a 300 Savage or 300 Savage Improved utilizing the 307 Win rimmed brass and trimmed down to proper length.

Piebald-I am pretty certain that JD no longer chambers the 6.5 and 7mm JDJ #2s -- only the originals on the improved .225 case. There were too many people pushing the envelope and getting into the red zone.

7-30 Waters,
That was an excellent post.

I'd like to ask a question and clarify a couple points if you'll allow me.

First, my question. I have never seen a TC factory barrel chambered for .300 Savage. To my knowledge it was never a factory offering. Did they in fact chamber for this one? Just curious to know if I missed something.

You said:
"Also by taking the taper out of the case from rechambering to an improved case, the case grabs the sidewalls of the chamber instead of back thrusting against the receiver."

Point of fact is that the .307 Win. and .308 Win. actually have a bit less taper than the normal Ackley Imp. configuration.... before they are improved.

On most of P.O.'s improved rounds with the approx. .465" case head diameter have a shoulder diameter of .455." The standard chamber shoulder diameter for .307's and .308's is .456-.457." So the act of "improving" the .307 Win. does not take out much if any taper at all, but it does change the shoulder angle to 40 degrees.

I will allow that some of the imp. versions based on the .308 Win. case have shoulder diameters up to .460," but even at that the .003-.004" less taper in the body is a minor point.

There is however, a significant gain from the much, much thicker .307 Win. brass. Everyone should section one of these and a .30/30 case. The wall of the .307 Win. case near the web is massive in comparison. And it is a point of fact that up to a certain pressure level, the case contains ALL of the pressure load. Past that point, it either slips back in the chamber or stretches back. But the thicker brass takes quite a bit more to stretch it, and thus it takes much of the load off the frame.

Also, you said:
"The answer to your second question. No a 30-30 barrel can't be rechambered to a 307 Winchester because a 30-30 case is slightly longer and won't allow a clean chamber cut."

Partially true.

You certainly CAN rechamber a .30/30 to .307 Win. or the imp. version and get a clean chamber, BUT... the .30/30 chamber is normally a mere .014" longer IN THE NECK if it is cut to spec. However, some vintages of factory chambers have been substantially longer than this in the neck area.

The downside is that whatever the factory cut by way of a throat is still going to remain after rechambering. The body of the chamber will all clean up just fine and dandy, but you will not be able to get a precisely cut throat unless you extend the throat on past what the factory cut, which is what Bower's gunsmith normally does.

Again, the original throat remains, and it will more likely than not be 1)larger in diameter than optimum for best accuracy, and 2) misaligned from the bore, often to a very substantial degree. This is sort of wasted area, but you can extend a proper throat in front of the remaining factory throat and get good results.

Best of course is to start with a much shorter .30 Herrett chamber and get rid of all the factory garbage work inside the chamber area.... as you suggested. And, yes, generally speaking, the 6 groove barrels were a better quality barrel from a finish standpoint. But the real down side to the 8 groove barrels is the total amount of bullet metal displaced by the wide rifling which comprise 50% of the circumference of the groove area.

It is not so much a matter of added friction, but rather more bullet metal displaced by too much cross sectional area presented by the ill-conceived equal land and groove rifling.

Also, the 6 groove barrels are 1-14" twist, which tends to produce lower pressures than a same rifling configuration with a 1-10" twist.

BTW, a lot of .30/30's have been rechambered to .307 Win. Imp., aka .30 Bower Alaksan, with good results according to Don Bower. But starting from a .30 Herrett is much better in my opinion.

I have a vested interest in the .307 Win. Imp. and intend to make some of these in the not too distant future.... as soon as I can get caught up on .30 Bellm barrels.

I am also still wanting to play with improving the .300 Savage case to see if dropping the pressure a bit with the added case volume and straightening out the chamber walls will make it work satisfactorily with factory .300 Savage ammo. If it will, it will permit the guy who does not reload to go to Wal-Mart and walk out with .309 JDJ/.308 Bellm/.30 Bower Alaskan type performance for his Contender/G2.

Hope this adds to the mix. .307 Win. brass is one of the very best platforms for wildcats or imps. in the Contender/G2. Glad to see this being discussed here. And thanks for the good input.

Mike

So Mike B. can we go on in this logic train to say a 260 or 260 AI type chamber with 307 brass has the potential to be a super performer?
This is assuming that we stay withing the design pressure requirements.

LouisB

TC,
As you may recall, probably several years ago by now, I often mentioned a .260 Bellm based on full length .307 Win. brass but having a chamber body .050" shorter than a standard .260 Rem.

I had done one of these before I moved up here to Oregon in '99 and made the mistake of marking it No. 001 for the owner. As the first one, it remains to date, so far as I know, still unfired, untested, salted away for its collector value.

I do have one new, unchambered 6.5mm handgun barrel still propped up against the edge of the solvent tank waiting to be chambered and tested. I had been tweaking Don Shearer in regard to doing the load development work, but we failed to get the endeavor coordinated. Thus the .260 Bellm remains on the back burner.

The strength of the .307 Win. brass is a significant factor from what I have seen. Improving the .307 Win chamber, thus increasing its volume some and permitting the firing of factory .307 Win. ammo is more likely to be allowable than simply improving the .260 Rem. chamber and having more risk of damage since the .260 Rem. brass is no where nearly as strong as the .307.

I tend to weigh the benefit of improving a chamber v. the cost of the dies and availability of them.

The thesis behind the .260 Bellm is to make it impossible to fire a factory .260 round in the shortened chamber while at the same time being able to simply shorten an off the shelf set of .260 Rem. dies by .050" and continue with minimal cost.

Also, with the 6.5mm at the allowable pressures, you do not need more capacity. You will do as well or better with less.

Paying beau coupe $$ for greater capacity and a 40 degree shoulder in a step backwards, while interesting, is an effort in futility. Why do it? Just because it can be done?
Bigger is not always better.

The question remains as to which will produce the best 6.5 performance, the very tough, smaller diameter maximized .225 Win case necked to 6.5 or the tougher still, larger diameter .307 Win. case. I don't know.

Off the cuff, my fine intuitive feel says that you can stuff enough powder in the maximized .225 Win. case to accomplish just about all that can be done in a 6.5mm Contender/G2 barrel, and the .307 Win. case may not gain anything.

Bigger is not always better. Case in point, inspite of the cost and limited availability of good 5.6x50 R brass, the fact remains that with its adequate capacity in the form of the 6.5x50 R Bellm, the higher allowable pressures in this small diameter chamber let it step out ahead of the 6.5 JDJ by at least 100 fps with 120 gr. bullets.

We may see somewhat the same thing with the .307 Win. case. It may not shoot any faster than either the 6.5 JDJ or my 6.5x50 R Bellm.

Don't know, and until someone cares to test it out empirically it will remain a topic of debate.

All the best,
Mike Bellm

Bellm TCs, Inc.
www.bellmtcs.com

Mike,

When you discuss the 100 fps higher velocity potential of the 6.5x50 R Bellm over the 6.5 JDJ with 120 grain bullets, is that with rifle or pistol length barrels?

Davit-
The 100 fps difference exists in 14-15" pistol barrels, and the margin in rifles should remain in the same ballpark.

I shoot a cartridge I call the "Thirty Something". I took a 14" 30 Herret barrel and ran a 300 Savage reamer in .10" short. I use 307 brass in a set of 300 Savage dies that I shortened .10". I load 150 grain Nosler Ballistic Tips over a load of Vit N140 to 2400 FPS and I've been shooting this set up for a few years. Taken a few deer and a nice bear with it. The interesting thing is the barrel was a real DOG as a Herret, but as a "Thirty Something" it is amazingly accurate.