RCBS & Model 185

[Tom]

I have several rifle muskets that shoot the RCBS Hodgdon except one.

It is an ArmiSport Springfield Model 1855 with a 1:65 rate of twist. It shoots the Lyman wadcutter and the 577611 (530 grains) very nice. My 1855 shoots the Lyman Old Style decently. I get tight groups and hit targets with those rounds.

But I can't get it to shoot the RCBS Hodgdon (416 grains). I have tried 30, 35, 40, 45 of Swiss 3F. I have also tried 30, 35, 40, 45, 50 grains of Goex 3 F. I have shot RCBS rounds with the cavities filled with lube. And I have shot RCBS rounds with a thin coat of lube in the cavity. Soft lube in both cases. The rounds are sized .001 of an inch less than bore diameter. None of the powder loads or lube will group well enough to shoot in competition.

The best result was with the 50 grains of Goex 3 F and a thin coat of lube. The group was 8 inches wide and 6 inches high.

I would very much appreciate any suggestions. Thank you for your help.

[Carolina Reb]

I suspect you have a barrel bedding problem. A lot of repros are pretty badly inletted around the breech and tang. This causes what I call 'magic load syndrome'. That is, one and only one combination of powder, bullet, lube (where's Lefty!) and cap shoots great, and everything else is lousy. If that is the case, glass bedding the barrel from the tang to about the rear sight generally fixes it. Good Luck!

[John Bly]

Your musket is telling you what it likes and dislikes. Listen to it. Shoot what it shoots best.

[bobanderson]

Different rifling twists will require different bullets to stabilize. The Greenhill tables, while not entirely accurate for hollow base projectiles, predict that a slow twist is better for a lighter ball, and for a heavier ball you need a faster twist.

Measure the twist rates for all of your muskets and I'm sure you'll find that they are different, hence the preference for one type of ball or another.

I tried using one load for several guns (muskets, smoothbore, BPCR guns) and the truth is, it just doesn't work all the time.

[Maillemaker]

Different rifling twists will require different bullets to stabilize. The Greenhill tables, while not entirely accurate for hollow base projectiles, predict that a slow twist is better for a lighter ball, and for a heavier ball you need a faster twist.

This.

I have a Pedersoli P1858 with a 1:48 twist. It will keyhole RCBS-Hodgdon bullets. I use the RCBS-Hodgdon in my Hoyt-barreled Richmond Carbine and Whitacre-barreled 1:72 P1853 Enfield. They do clover-leaf accuracy off a bench at 50 yards with the RCBS-Hodgdon.

But with the fast 1:48 twist, I have found best accuracy (but still not skirmish-grade) using heavy Minie-style bullets. I got a good group (clover-leaf) with the RCBS-500M using 60 grains 2F Goex, and have also had luck using the Lyman 575213OS with a custom core pin to make it heavy like the Lyman 575213PH. I'm still experimenting to get something that works consistently.

So I believe that indeed as a general rule, slower twists will work better with lighter, shorter bullets, and faster twists will work better with heavier, longer ones.

Steve

[Tom]

I wish to thank everyone for your comments. I've been skirmish shooting nearly 14 years. It has been my intention to glass bed the stock and I will do that now sooner than later. I hope that improvement helps my Model 1855 shoot the RCBS Hodgdon. Just wish I could glass bed my stocks as well as some I have see. Thanks again, I appreciate it.

[george7542]

I just finished a glassbed job on armi sport 1861 I picked up from a reenactor. the gun would not hold a group with anyload just received my barrel back from bob hoyt and decided to glassbed it before it goes to the range for sight in I had to do no wood relieve the spacing between barrel and stock was so much

[Tom]

I wanted to provide a follow up on the question I asked and the help I received. I went and shot the Model 1855 this morning with the RCBS Hodgdon and it grouped really nice.

There were 3 things that made the difference.

1 I glassbedded from the tang to the rear sight.

2 By pure coincidence, I happened to drop one of the Hodgdon rounds nose first into my sizing die and noticed it fell into it very easily then wiggled inside. That told me when I pushed it down the barrel, it was not centered. It was crooked.

I cast from another RCBS Hodgdon mould. It was fuller and all the lead bands were sized down. This helped to keep the round centered.

3 I called a friend who always gives good advice. He told me to size my rounds .001 of an inch larger than I had done in the past.

This morning was kind of foggy but I had to test it. I got the nicest group and I know it can be tightened.

Thank you everyone.