Author Topic: .40-70 Sharps Straight from .405 WCF (Hornady) brass (Read 1682 times)

ShortStake · « **on:** September 09, 2005, 10:05:09 AM »

Gents and Madams,

Good news for those that may be contemplating a .40-70 Sharps Straight chambered rifle.

From the Single Shot Exchange, September 2005, page 30:

Quote.......

"Just a note to let you know that Schuetzen Gun Co., in association with Pacific Tool and Grinding and other gunsmiths, has developed a new chambering reamer for the popular .40-70 Sharps straight cartridge that uses:

-existing standard factory made brass (i.e., .405 Winchester Hornady brass)

-existing standard factory die sets (Hornady .405 Win New Dimension dies)

-standard .408-.409 inch dia. bullets.

- ability to seat out bullets one band and one grease groove, if desired.

-1 degree tapered land throat (no stepped counterbore)

Because the original .40-70 Sharps straight was the case originally used as the basis for the .405 WCF and just lengthened, it seemed logistical to use the new .405 WCF Hornady and reverse the changes. We also used an original Winchester factory .40-70 Sharps chamber blueprint as a guide.

Testing has shown that by shortening the Hornady .405 Win. brass .100" and sizing in the Hornady .405 Win. standard full length die, the existing expander plug needs only to be run in about 1/8" to bell the case mouth, and a .408 to .409 inch diameter bullet will seat and held firmly without looseness or excessive constriction. This is due to two reasons:

-one, is that the dies are made of the stand .411 dia. .405" bullet, therefore, the die does not excessively size the brass, which is good, for this also compensates for the slightly thicker case wall near the bullets' base, due to the necessity of shortening the case by .100".

-the smaller diameter .408" and .409" bullets used in standard .408" barrels produced by barrel makers for the .40 calbier black powder rifles today.

This is the answer to years of problems with non standardized chambers, chambering reamers and reformed and custom made brass of insconsistent quality that has caused headaches for consumers and gunmakers for decades. Schuetzen Gun Company at 970-635-2409, (M-F, 9am to 4pm) or Dave at Pacific Tool and Grinding Company at 541-826-5808.

Richard Kinney, Drake, Colorado"

Unquote........

zrifleman · « **Reply #1 on:** September 10, 2005, 06:53:06 PM »

Shortstake-- I have an original 40-70 SS in a Borchardt sporter. I tried using 405 Winchester brass from Hornady. I have run it thru Lyman dies, RCBS .406 and RCBS original dies sets and they won't chamber without excessive force and lots of problems. I tried neck reaming them but the problem persists. The center of the case won't size down enough. This might work in the "new" 40-70 SS chambers. Buffalo Arms warned me this would happen. The solution was to use their "original" 40-70 SS brass and RCBS .403 dia dies--no more problem.

ShortStake · « **Reply #2 on:** September 11, 2005, 01:23:53 PM »

zrifleman,

Not to take anything away from the wizards at Buffalo Arms......

My initial mental comparison is with the Sharps Borchadt and the 1874 Model Sharps and wonder what the comparison is with respect to the camming power of the action to chamber cartridges? Being unfamiliar with the Borchadt model's activity in this respect makes for my question of comparison.

Perhaps your original Sharps Borchardt may have been chambered with a reamer worn past minimum exisiting specifications at that time? Have you tried a chamber casting with CerroSafe?

Obviously the difference in .403 and .408 diameter bores (and bullets) is also a consideration. As you mentioned, neck reaming failed to correct your hard chambering problem while Buffalo Arms "stretched" brass did alleviate the problem. Have you ever tried utilizing a Hornady .405 Winchester Full Length sizing die on the brass that would not chamber?

Trying to reverse history/time with SAAMI specifications could also be the culprit?

Believe the various .40-70 Sharps Straight configurations to be found were the impetus for Schuetzen Arms to come up with their chamber reamer. Their reamer design would certainly be my preferance for a "new" .40-70 Sharps Straight chambering. My next BPCR project is awaiting the afore mentioned reamer from Schuetzen Arms. This project will mate a Green Mountian .408 octagonal barrel with an original Winchester 1885 Highwall to be chambered in .40-70 Sharps Straight and utilize .405 Winchester (Hornady) brass..

zrifleman · « **Reply #3 on:** September 13, 2005, 02:26:00 PM »

Shortstake--I revisited the 405 brass and my 40-70 SS. The base is too large on the 405 and the brass is too thick at the neck (.012" versus .020"). My gun is an original factory chamber and with correct brass , no problems. Bore diameter on original .40 Sharps was .403. What you are doing is chambering the gun to .405 Win and cutting brass to 2.5" Shiloh and C Sharps are using blown out 30-40 Krag brass which has a rim thickness of about .050" or about .020" thinner than 405 or original 40-70 SS. I'm sharing this info with you so that maybe you can avoid some of the confusion on chambers, brass and dies common to 40-70. Because the 405 brass is a lot thicker and heavier, expect much higher pressures with a loads for 40-70.

Lead pot · « **Reply #4 on:** September 22, 2005, 02:08:02 PM »

The .405 win case made by Hornady will not fit my Shiloh chamber unless you rework the inside diameter of the case.
Were the problem starts is were the base of the bullet is seated in the case. The Hornady case wall is too thick, and when the bullet is seated it pushes out the case wall which in my case with my lot number of the brass which over sizes the case wall by .0015.
By forcing a empty case with a bullet seated into the chamber then pulling the bullet the base of the bullet is swaged down to .4065 from the .408 starting diameter.
I have 200 of these cases, I chucked them up in the lathe and turned down the inside of a few cases and they work fine. But the rest I use only for paper patch loads and the cases are ideal for that purpose.

Kurt