Ball diameter for .54 GPR

[lanedh]

Hi Gents:

Two questions with regard to the flintlock Lyman Great Plains Rifle in .54 caliber---

First: I am building this from a kit and am getting close to test shooting for target work. I have seen about an equal number of posts as to which round ball shoots better: the .530 or the .535. I would appreciate inputs from some experienced GPR shooters before I order a box of both sizes (if .530 is not doing well, I don't want to buy bullets I won't use, nor pay the hellish postal rates they get these days). Along with your preference for ball size, what patch thickness should I start with? I'll probably use ony a spit patch for loading, and will wipe between shots with some cleaning compound.

Second: I understand that the breech plug on the GPR has a smaller ID than the bore. What is the capacity of the powder chamber when filled to the top? If I am working up from a small charge and the charge doesn't fill the powder cavity, what is recommended as filler?

Looking forward to some fruitful advice...
BJ

 

[BrownBear]

Based on experience with my own 54 GPR and several others owned by friends, I'd sure start out with the .530 ball, as well as both .015 and .018 patches. After several hundred rounds of breakin, mine settled into a preference for .535/.015, but initially it took two men, three small boys and a lot of cussing to seat the .535, even with a .010 patch.

But some of that was probably my fault. Based upon experience with subsequent Lymans, I don't think I got all the bore protecting grease out initially, and it simply took time to go away. Before shooting yours, hie on down to the automotive supply counter and get yourself a can of brake pad cleaner. Apply to a patch and make a pass through the bore. In my new bore, it took only three patches to have the bore mirror bright, but in the first GPR no amount of cleaning with other gun solvents ever produced a gleaming bore.

And what if your gun doesn't like the .530 balls? Go to a thicker patch. They're certainly a lot cheaper to ship than balls. I've recently been playing with patches I made from Walmart pillow ticking, and results are good. In spite of all, I may go back to the .530 ball at least for hunting reloads, simply because they are a little easier to seat, and we're talking a difference of about 1" in group size at 50 yards.

Hope I've created the impression that ball size can be a bit of a "moving target" for your GPR, depending on what you chose for patches as well as whether you want a very tight load for targets or something a little easier to deal with for field shooting.

I share your concern for shipping costs and opted for molding my own. Lee molds cost little more than a box of swaged balls, so it made sense to me. Which did I pick? I bought both .0530 and .0535. I've only got a couple of thousand rounds through my GPR, so I haven't quite settled in on the "right" ball diameter for it.

 

[Russianblood]

My .54 GPR prefered .527 RB and #40 drill cloth patch.

 

[410-er]

I tried .530 with .020 pillow and got 1 1/2" groups.Good hunting accuracy.Tried .535 with .020 and got a real nice clover leaf.It is a little on the tight side to start but I cut my pillow squares a little on the big side so I can fold it over the top of the ball to protect it when starting it.Will use the .530's till they are gone but will go to .535 after that.

 

[Swampman]

I'll quote my favorite author.

"I'd use a .520 ball.......and 60 grains of 3F GOEX."

Use a patch thick enough to get some pretty good resistance when you load it. Hemp canvas cloth makes the best patches. Denim or cotton canvas work pretty good too. 1/3 Olive oil, 1/3 lard, and 1/3 bee's wax makes a great lube or you can just use olive oil. Cleaning is best accomplished with windshield washer fluid, or Windex, or just tepid water.

 

[Old Salt]

Bluejacket,

In the past with my .54 GPR flintlock I used .530 ball and .020 oxyoke patches. Now I use pillow ticking.

Old Salt

 

[Keppy]

My Investment Arms like .527 and 6ogrs FFF, patch tight enough to hold the ball. It loads very easy.And shoots great out to 75yds.

 

[rancher]

.530 with pillow ticking works for me.

 

[d.thomson]

I use .530 balls I cast my self and oxyoke.020 patches with a 4 to 1 water balistoil mix for lube. I can clover leaf off the bench using 75 grns of 2f goex. My 2 cents F.K.

 

[Rocky Johnson]

Question Bluejacket, Don't your local Wallmart have balls?
I must be lucky I have I have quite a few places to get shooting supplys within 15 minutes of home including real black power. :wink: Rocky

 

[lanedh]

Our local 'Mall Wart' gave up selling guns a couple of years ago in response to heavy pressure from "forces for Good in the community". They have shotshells, targets, clay birds, cleaning kits and patches, mothballs, ping pong balls, but no round lead balls. The closest sources of real black powder are about an hour (RI: walk in, bring your wallet, choices are Goex and Swiss, no permit needed) and a half-hour (MA: bring fourteen kinds of photo ID and both sets of grandparents).

To all who responded: thanks for your insights, looks like .530 is the winner.

Brgds, BJ

 

I'll second the .520 ball. I have several .54 rifles and I use the .520 ball and just regular pillow ticking from wal-mart. All I adjust is the powder because of the different lengths of barrels.

 

[rkite]

.530 Hornady round balls (Walmart and K-Mart have them) .018 Ox Yoke pillow ticking and 80 grains of 3F Goex. It shoots better than I can. I tried .535 balls but they were really hard to load with .015 patches.

 

[sniper68]

:hmm: Timely post. I've "had" about 50 each of some .530 and .535 cast balls laying around for the last 25 years. Since I don't got no .54 cal I donated them on another forum about 2 months ago cause I'm that kinda guy. :barf:
Well this afternoon the mailman brings me a huge box in perfect condition. In it, is the prettiest custom Hawkin I have ever seen, much less owned.:bow: In .54 cal.!!! :shake: Just couldn't help it. :wink: :grin: With my .45 & .50's I have RCBS or Lyman molds in two sizes for each. Due to My finical situation I got a 100 Hornady balls and a close out Lee mold, both in .535 dia.from Mid South. A little late to ask, but in anyones opinion,what size ball in general works best in a Green Mtn. barrel??
sniper

 

[paulvallandigham]

Measure the bore with calipers, to be sure. All barrels can vary a little. There is no real industry or company standard, altho Green Mountain barrels are among the better barrels made today. The land to land diameter will tell you what size ball to use. You usually want a ball diameter to be .10 to .020" smaller than the bore diameter. The groove diameter, divided by 2 to get the groove DEPTH, will give you a good indication as to what size patching you can use.

For example: my brother just helped a good friend make a new .40 cal. rifle, and that barrel happens to have a fast twist, and relatively shallow rifling of only .004" in depth. My .50 GM barrel has groove depths of .006". My .50 Long barrel for a Hawkin style gun has deeper grooves- I believe about .007" ,if memory serves me right. A larger caliber rifle, like a .54 does not have to have deep grooves to do a good job of spinning a PRB, or shoot a conical. Some do, but many do not.

 

[bart_anastasi]

This replay may be coming a bit to late but never spit patch a round ball. Period.

If there is anything that shooters should agree on it is that constency is the key to good shooting and a spit patch is the exact oposit of that.

What happens when you wet a patch with any lube is that the fibers of the patch are

1. protected by the lube from the fire within.

2. expanding under the influnce of the lube to keep the patch tight.
(read seal in the gasses evenly around the ball clear to the end of the barrel so the gases release evenly the powder blast not deflecting the ball )

With a spit patch the lube starts to

1. Wet into the dry powder below (not good)
2. Dry alowing the patch to be burned and damaged
3. shrink and lose tension with the sides of the barrel. (read allow gases to pass around the ball you know not where in a unpradictable way)

You would always be better to use sweat from your face or nose area for your patch since there is some skin and body oil there.
Get some Bore Butter

If you think it thru with a spit patch you could expect a different impact point with a ball all thing being equal with the patch at diferent stages of wetness.

And if you are waiting for that big buck for a hour or more you could expect a big miss shooting a patch that is now completly dry.

Also difficulty in loading a ball with a thicker patch is difficult only in the first inch of so of travel once the bullet has excepted the rifeling there should be no real difference worh mentioning.

The tighter the patch the tighter the groups.

Assuming yu have everything else worked out.

Are your round balls round is more important than say which patch lube I select since nothing you do will make any difference if you use say a bargin brand ball with flat spots.

Beleive me I have been there.