Ever had this happen ?

[pulaski]

Rice barrel , 50 cal. , 42"swamped .
For years it loved 60g. 3f . Groups openned up a bit , thought it was my eyes .
At todays shoot thought I'd try 70g. (not sure why).
Came home with a 1st place (98 at 50 yds. offhand) . Shot a 1.5"group .
Seems like I found a new load .
Question , why the change ? Changed nothing else .
Thanks , Steve

[bob in the woods]

It changed 'cause its getting worn. Too slick?  I have heard of roughing up the bore a little to get the gun to go back to it's old ways.

[Daryl]

Why not continue shooting 70gr.3F- then 75, maybe 80 - 90 whatever it takes. The benefit will be increased velocity and flattened trajectory- I do not, however, believe the barrel is shooting the same speed with 70 now, as it did earlier with 60gr.  I do believe that barrel condition prefers 70- and so would I.  I'd even wager that 85gr. 2F would shoot better yet.

Roger Fisher had that same thing happen to him twice, so far. The first time was around 45,000 rounds and the second was this year, around 47,000 rounds fired.

[pulaski]

Thanks guys .
Don't get me wrong I'm not complaining .
Bob you might be on to something with the "smoothness" increase .
After deer season I will tinker with the load more .
Appreciate the help and insite .
Steve

[Daryl]

A change in lube or lube composition will also change what it wants for powder.

[hanshi]

45000 plus rounds is a lot of shooting for an ML.  I would hope bores last more than just a few thousand like smokeless rounds do.  I seriously doubt I average more than a few hundred in any one rifle per year.  My shooting is spread over some four or so guns though concentrated more in one or two.  I'm glad bp doesn't create the heat, pressure and abrasion smokeless does.

[BrownBear]

If you're "set" on charges toward the lighter side, you might also experiment with changes in patching material- a little thicker in my experience.  I'm not a match shooter by any means, but I shoot enough to put lots of rounds downrange sooner or later.  I find the "smoothing" thing fairly common in a new barrel, seen as a drop in accuracy and seating effort after a few 100's of shots.  With no change in charge, I restore or improve accuracy simply by going up "one size" in patch thickness.  I've seen it after thousands of shots too, but it's subtle and kinda sneaks up on you.  Not saying this is the explanation behind your experience, but easy enough to check along with stretching your powder measure.

[northmn]

It is quite common.  Heard of roughing up the bore also, but like Daryl I would go to the load that works.  Usd to see that a lot in the old Numrich barrels where I would go to a thicker patch after a bit of shooting.  Personally I do not think shooting a greased patch wears the bore, I think we polish it when we clean after the shooting suing dry patchs and rubbing some of the crud up and down the bore.

DP

[Kermit]

I remember a few decades back hearing a couple of geezers, now both gone, talking about how one of their flinters was "shooting slick." He took the piece home, plugged the vent and filled the bore with urine--presumably his own. He let it stand overnight, and dried and oiled it. Claimed that restored its accuracy at the next shoot.

Urban--or rural--myth? Jerking the chain of the young guys? 

[BrownBear]

Only one way to find out....   Um, pour me another cup of coffee, wouldja please.   

[longcruise]

Just a change in powder lots or brands could make a diff.

[Roger Fisher]

I remember a few decades back hearing a couple of geezers, now both gone, talking about how one of their flinters was "shooting slick." He took the piece home, plugged the vent and filled the bore with urine--presumably his own. He let it stand overnight, and dried and oiled it. Claimed that restored its accuracy at the next shoot.

Urban--or rural--myth? Jerking the chain of the young guys?  

Don't laugh, it works (but it's only a temporary fix) a little JB bore paste also helps. Still better is to give the ol gal what she wants - more powder and go with that.

BTW, You may believe it or not my ol Getz barrel has over 50,000 rounds thru her this is since 89 (1989).  Did I say I shot her a lot?

Also, btw Barbara did wonder what that yellow stuff was in the jar on the laundry shelf.

[pulaski]

I'm OK with the change . I prefer the powder increase as long as the rifle remains accurate , this way my target load is potent enough for deer hunting . Allways hated increasing the powder for more punch and having to sacrifice accuracy .
Took it out back today and shot it somemore , the 70g charge has ben upped to 74g . Ripped me a nice 1.25" hole with 10 shots at 50yds. (used my elbows on the bench)
I was just curious as to why the barrel changed . Same powder , patch , ball , lube , etc.
Appreciate all the input .
Steve

[Daryl]

Steve - it either shot slick as the saying goes, or perhaps your accuracy requirement got stiffer.  In any event, I've never seen a round ball twist barrel shoot well with a small powder charge at any of the longer ranges.

With a slick oil patch, even my 60" twist .45 demands 75gr. 3F to shoot well.  With spit or water based lube, it shoots fine with 65gr. 2F.  Oil requires 85gr. 2F. Go figure.

[BrentD]

I was just curious as to why the barrel changed . Same powder , patch , ball , lube , etc.
Appreciate all the input .
Steve

Same batch of powder?  Variation from batch to batch can be extreme.  Even for Swiss powder which is generally regarded as the most consistent. 

[pulaski]

Powder batch is same . (Got a case at a time)
Daryl, I know what you mean about the sweet load changing with the lube . I normally use a bear grease lube and have noticed a change when going to spit .
Steve

[Roger Fisher]

Powder batch is same . (Got a case at a time)
Daryl, I know what you mean about the sweet load changing with the lube . I normally use a bear grease lube and have noticed a change when going to spit .
Steve

Gotta askya,,,, Which shoots tighter groups.... 

[Daryl]

My own test of that was with the .58 Hawken, back in the late 70's. I don't know what Steve's findings are, but I also chronographed mine. The bear grease gave an average of 100fps higher velocity and required more powder to get good accuracy. Spit gave the best overall accuracy, with the lowest shot to shot velocity spreads - from 5 to 10fps depending on the load.  I ran from 90gr. to 180gr. in the test- all 2F of the GOEX or GOX - whatever was available back then. With bears grease, 160gr. 2F gave the best accuracy, but with spit, it was 140gr.2F. 90gr. would barely stay on a 9" pie plate at 100 yards.  140gr. with spit, shot 1 1/2", 5 shot groups. Admittingly, the hooked butt took a toll on my shoulder even though the rifle weighed over 11 pounds. Maybe it was the 600gr. slugs I shot with the same powder charges?

[satwel]

You might be experiencing the effects of the vent eroding. As the vent gets larger, velocities become more inconsistent. If it's easy to change, you might want to replace the vent liner.

[Daryl]

Cap-lock in my tests, not a flintlock.  Results were repeatable - old nipple, new nipple, didn't matter. I used to be a bit paranoid over worn out nipples and changed them frequently.  I never let them get worn out. I've probably 1/2 dozen I saved over the years & all measure the same as brand  new.
You are right, though, a worn vent or nipple flash hole will result in reduced speeds, sometimes a lot of speed loss.  In doing the test, 90gr. was shot using both lubes and chronographed, then 120gr., 140gr., 160gr., etc, changing out the lube and recording the results. In all cases, the oil gave higher speeds and slightly poorer accuracy.

I recall that bear's grease was good for about 2" or 2 1/2" at 100 yards, not quite as good as spit, but certainly plenty good enough for hunting, considering the ranges involved.

[pulaski]

Roger , I now lube my patches with bear grease , then put them in my mouth . ( Yea I know it's a little wierd but it really shoots tight groups ) My experience is the bear grease/spit combination is the tightest . I found it to be tighter than grease alone or spit alone .
As to the vent liner , never even thought about it , but it cetainly makes sense .
Again , I'm happier with the old girl now than before . Her's hopeing she doesn't change for a long time . ( I haven't got many 1.25" groups with a hunting flinter )
Thanks , Steve

[Daryl]

You might be experiencing the effects of the vent eroding. As the vent gets larger, velocities become more inconsistent. If it's easy to change, you might want to replace the vent liner.

Good point - Definitely makes a difference in velocity.