when to neck turn 40/65

[kokomokid]

I am still working on getting a good load for my 40/65. Chamber cast shows a tight .430 neck which is cut straight first .500 then has .004 shoulder and then the usual taper. I am useing R-P 45/70 cases formed to 40/65 . If I stuff a .4105 sized bullet in the case , lt can sometimes be a tight fit. WHAT should my brass neck thickness be after forming? What would be a minimum thickness?

[Boz330]

What do your grooves mic? .4105 is pretty big for a 40-65 and Remington brass is on the thick side. I size mine to 409 and 408 will work as well.
Have you shot these yet to fire form them? I wouldn't think you would have to neck ream them but maybe the chamber is that tight.

Bob

[kokomokid]

bbl slugged .409/.401 and shoots best so far with snover sized .4105. I was thinking maybe brass is a little thick after being necked down.??

[NickSS]

I bought a C Sharps high wall some time ago and it had a really tight chamber so I sent it back to them along with a case that had been fired but not resized. When it came back it feeds reformed remington brass just fine with a 410 sized bullet. In fact it even shoots better than it had before. I have found that tight chambers and BP are not as compatible as tight chambers and smokeless is.

[Boz330]

I don't know if this will help you but I checked 3 different fired cases last night and here are the results.

Starline .430 OD, .408 ID, wall thickness was .012 to .0125.

WW .428 to .430 OD, .410 to .412 ID, and wall .010 to .0115

Rem. .426 to .427OD, .410ID, wall .0095

The Starline and WW were shot in the same chamber, the Rem was fired in a different chamber. The Starline brass is factory 40-65, the WW and Rem was formed from 45-70 brass. The measurements were taken from several different cases. Normally you here that Rem is thicker brass but the measurements here don't indicate that, but this is some brass that I got with a gun when I bought it and I don't know the process it went through. It might have been reamed or neck turned. I just took the measurements about an 1/8" down from the mouth.

Bob

[kokomokid]

Thanks Boz, looks like not many people here turn necks. I just picked up some THIN wall WW brass and before length trimming it looks to be thicker than R-P same as you are showing. I can size bullets to .409 but this has not shown much promise. Think I may get a hand turner and try going down to .008 neck unless someone tells of bad experince??? I am surprised that factory 40/65 from starline is that thick.

[semtav]

just measured some of mine shot from a Browning.
R-P resized 45-70
.4285 OD
.4105 ID

I shoot .411 sized bullets in mine.
Brian

[texasmac]

Using a tubing mic I just measured the neck walls of several lots of Winchester 45-70, Remington 45-70 & Starline 40-65 brass. Here's the averaged results:
Starline - 0.0100"
Winchester - 0.0105"
Remington - 0.0110"

I also measured the walls 1" down from the neck rim to get an idea on how fast the walls thicken.
Starline - 0.0175"
Winchester - 0.0150"
Remington - 0.0180"

I did not measure the case volumes using water, but based on the limited data above I'd expect Winchester to hold the most volume of powder, followed by Starline, then Remington, which should not surprise anyone.

By the way, concerning neck turning, It's my opinion that in some cases (no pun intended) it makes sense, but in others it does not.

To give you a better example of the benefits of neck turning, the factory chamber in my Browning .40-65 BPCR has a well defined neck. The neck is 0.5" long with a constant diameter. To take advantage of the well-defined neck and to facilitate uniform bullet release, I turn the necks of my Remington brass to 0.010". If the case necks are not turned, the inside diameter of the neck of a fire-formed case would decrease as the case wall gets thicker.

An example when not to neck turn - The factory chamber in my Browning .45-70 BPCR does not have a well-defined neck. The chamber tapers from the rim recess all the way to the chamber/throat transition step. Since the case walls are tapered the case dimensions should come close to matching the chamber taper within a half inch or so of the case mouth, resulting in a constant inside diameter to match the bullet diameter. Therefore, IMHO, if the necks were turned to a uniform thickness it would be counter productive and result in a negative taper in a fire-formed case.

Again, the above comments are only my opinion and are an example of why it's important to make a good chamber cast or impact impression. Without knowing exactly what your chamber dimensions are, it's hard to determine the pros or cons of some case preparations and reloading steps.

Wayne

[kokomokid]

I did not know browning cut the BPCR with a straight neck on a 40/65. Did all of them have the same chamber? Mine is a custom job with about a .004 shoulder and .4302 straight neck. I may have to quit buying goodies and invest in your book.

[texasmac]

kokomokid,

Yes, all the original Browning .40-65 BPCR have identical chambers with a 0.5" long straight neck.

By the way, my book covers the Browning BPCR's in great detail, including chamber dimensions and disassembly/assembly of the action and a lot of other stuff, but it does not specifically address reloading ammo for the rifles.

Wayne