18-twist .40-65 revisited.

[Distant Thunder]

18 twist .40-65 bullet length?

A year ago I start a thread asking for ideas on what would be the optimal bullet length for a .40-65 with an 18-twist barrel with intention of using it for silhouette. It has taken a full year, but I believe I have an answer to my satisfaction and I thought I’d follow through and let those interested know just where I ended up.
Just a quick review of what I’ve been working with, it’s a C. Sharps 1875 that has been rebarreled with an 18-twist Badger barrel and chambered in .40-65 with a long free bore, .375” long, and a chamber length of 2.150” so .45-70 brass doesn’t require a lot of trimming after forming. I mention all this so you’ll understand that it not just a standard .40-65 chamber.

This rifle had been sitting in my safe for a few years while I played with bigger cartridges with more reach for the long matches. I have been shooting paper patched bullets in long range matches for several years. I make all my own paper patched molds and I have done fairly well with them. A friend asked me about making a special 2-diameter paper patched bullet mold for his and another friend’s long free bored .40-65 rifles. So the three of us embarked on the development of an elliptical 2-diameter paper patched bullet and it was quite successful. They have both had very good accuracy using that bullet design.

Working with my rifle in hopes of using it for silhouette I first tried the 3 different grease grooved bullets I had on hand. These are the RCBS 40-350, the Lyman/Snover, and a Fred Leeth version of a Creedmoor bullet at 420 grains.

I wasn’t able to get much better than 2 MOA out of the Snover or the Creedmoor. The RCBS bullet shot fairly well perhaps because it was the shortest of the 3. I had used the RCBS in this rifle for silhouette in the past for chickens and pigs and it worked well. I tried it on rams in one match and it did well there too, but is it the heaviest bullet I could expect to shoot well out to the ram line, probably not.

Thinking back to paper patched I decided to give them a try mostly because I could make the mold myself and adjust the length to the optimal. It took some experimenting with a couple molds to find what would best fit my rifles chamber. The 3rd design turned out to be a winner. It is a paper patched round nose design with a portion of the shank that patches to .4093” to fit my free bore and just long enough to allow the bullet to be seated in the case .075”, very shallow. The rest of the shank patches to bore diameter, .400”. The OAL is 1.250”. The general consensus was that 1.280” is max in an 18-twist, I decided to error on the shorter side. Cast at 11-12 BHN it weighs 382 grains, from 18 to 1 it is 385 grains. I went with the harder alloy.

Shallow seating eliminated the paper rings I was getting with a deeper seated design I tried first. This also helped with powder capacity. Using a .060” LDPE wad the rifle decided it liked 72.0 grains of 1 ½ Swiss sparked by a Remington 2 ½ LP primers. I used R-P brass because it fits everything so well. I decided to scope this rifle because my aging eyes struggle to see the irregular shapes of the silhouettes. Once I put the scope on this rifle I knew it was there to stay, I love it! This load gave me 1355 FPS, not bad for a .40-65!

This load combination has regularly produced 1 to 1 ½ MOA groups on my 200M range. It also did very well at two local gong matches earlier this summer shooting at 200, 300, 400, and 500 yards.
After working out what I hoped would be an efficient wiping routine for silhouette while shooting paper patched, I felt I was ready to head to Alma, MI for my first silhouette match in 4 years. I easily got sight setting for my scope Friday afternoon. I had the good luck of have Brent Danielson join me at the match and we started on rams Saturday morning. I hit 9 rams, all went down. The chickens were a disappointment. I put a lot of time into my chicken hitting before the match, but I could only manage one chicken. I did come close many times. Moving to the pigs things were going very well until I made a real boneheaded mistake that cost me one pig. Just a total mental break down, but I recovered and finished with 9. Ending on the turkeys late in the day when the conditions were at very least challenging I came away with 7. Now I am an AA shooter so the 26 was pretty good for the first day. I would be much more confident and settled down on day two. Unfortunately I was hit with an unexpected illness early Sunday morning and it put me down for the count, I was unable shoot at all. Still the one day proved a couple things I needed to know, my bullet/load would take down the rams and shooting paper patched bullets in silhouette is much easier than many would have you believe.

All in all my quest for the best bullet for my rifle in silhouette matches didn’t go the way I thought it would, but it turned out much better than I thought it would. I’d call it a success! With a little luck and continued good health I hope to shoot more than one match next year, certainly more than one day.

Jim

[BFD]

Jim's bullet was fun to watch - you can learn something by watching them in the scope when the light and background is right, and it was at Alma. I could see it very well, and it flew without the slightest wobble. The rams went down slow, but rams always go down slow. I thought a few of mine were never going to fall, and I was using a .45. Notably, on Friday's practice shooting and especially on Saturday, we had substantial headwinds. Not super heavy but brisk enough. Yet the bullet remained stable. I think headwinds are hardest on bullet stability, but he had no problem there either.

It is pretty clear to me that the .40 will work, even with the slower twist. His bullet arrives on target pronto, so it seems to be carrying its velocity well, even though it is a bit on the blunt side.

Accuracy was good on Turkeys too, though his spotter probably cost him one or two.

But best of all, he is healthy (or at least healthier) now. We really should have hospitalized him on Sunday. He made your average zombie look healthy and robust on Sunday morning

[beltfed]

Jim,
Glad that bullet is working out.
good shooting.
Like at the gong matches ..
Arnie

[SSShooter]

Arnie - how is that 368gr 40cal greaser you shared shooting for you? I've gone strictly 38cal (bad shoulders), so passed them along to a fellow out west who has a 1-18" twist original Ballard Creedmoor in 40-85. I'll have to check in with him to see if he has had a chance to give them a try.

[beltfed]

Glenn,
Actually , I have not shot my EMini greaser all year in the 40-65. I am now shooting only the Dual Diameter Elliptical PP bullet
Jim had mentioned above. The DDEPP bullet is designed after the profile of the EMini-same length 1.325.
Note that Jim's similar 2 D EPP bullet is at 1.25" long and a bit broader elliptical nose to gain some weight for knocking down sillywets.
Will be interesting to learn if your friend's 18 twist rifle will stabilize the 1.325" EMini. It may be ok to good at up to midrange.
He should be able to get good velocity out of that 40-85. Note that I am loading 74.5 gr Swiss 1.5 under both the DDEPP and the Emini
for about 1400fps across my Oehler.
beltfed/arnie