Tried a .490 PRB in my GM .54

[Lonegun1894]

So I tried a .490 PRB in my GM .54 smooth-barrelled GPR. I have been getting decent groups using .527s in it, but had some .490s also so loaded some up. At 50yds, the first shot was in the exact center of the 1.5" bullseye, with the next 8 shots scattered about 4-5" in any direction of it for a total group size of 9.5" across. Ok, "group" is the wrong word, more like pattern. I think I will try them again with different powder loads, and above all different and thicker patching, or maybe multiple layers of patching. This was with 60grs of FFFg, a load that usually does groups half this size with .527s, but tightens up with more powder. I have not yet settled on a load for this barrel, as I think there is a lot of room for improvement. So far, best groups have been with 80grs FFFg, a leather wad punched out with one of Ohio Ramrods punches, and a .527" ball patched with a patch cut from a cotton t-shirt giving 4-5" groups. So there's plenty of room for improvement, but it is accurate enough for deer out to 50-60yds. I dont think I trust myself beyond that with this load, but hoping to improve groups with it before deer season.

 

[paulvallandigham]

T-shirt cotton makes pretty good CLEANING PATCHES, but LOUSY PATCH Material to wrap around lead balls. The weave is too open to give a good seal. If you read your spent patches, you will easily see this. The typical T-shirt is so thin( measure with either a micrometer, or caliper) and varies so much from one area of the shirt to another, that you waste your time, trying to use it as patch material.

Use mattress ticking, or pillow ticking( thinner), or linen, or pocket drill, or denim for your ball patches. Avoid most other fabrics because they have synthetic fibers in them that only partially burn and leave behind residue that is difficult to remove unless you use modern solvents designed to remove plastics.

You can buy .530" and .535" ead balls- both swaed a

 

[Lonegun1894]

Paul,
I couldn't agree with you more about the t-shirt being a lousy choice for the gas seal. I was just using it to center the ball in the bore while depending on the leather wad to provide the gas seal though. As to ball size, I have molds in .527, .530, and .535. so those aren't a problem at all, and have all been tried. My GM barrel actually measures right between .539-.540, and I haven't found patching thin enough to be able to try the .535s patched. The .530s are a real pain to seat with any kind of patching, and the .527s require a mallet with anything thicker than t-shirt material, which is why i tried it. Now if we're talking bare ball, the .535s do best with .530s being next, and the .527s coming in last. I am still not done experimenting with different cloth types, but really think that the .527s will do best patched based on the results so far. That doesn't mean I am done experimenting with the larger sizes, but time will tell. I definitely was not impressed with the .490s, but will try them a few more times with different patching and more patching to see if I can improve on my results so far to see if I can get something at least a little more respectable than 9.5" at 50yds.

 

[Flash Pan Dan]

Lonegun,

Roundball posted that he used a .520 ball with a .022 patch and got excellent results with a 80 grn. charge of 3Fg. I tried the same combo with a 70 grn. charge and got one big ragged hole groups at 25 yards. This was in my .540 bore trade gun. I used the Ox-yoke pre-lubed .020 patches which actually mike out to .022. Many thanks to Roundball for all his testing and willingness to share his findings.

 

[BrownBear]

...and the .527s require a mallet with anything thicker than t-shirt material, which is why i tried it.

Have you tried muslin? It can get real thin, and especially the Super Muslin is tuffer than tuff. I have a GM 62 cal smooth barrel that is way tight, requiring me to drop all the way down to .595 balls if I want to use ticking. It shoots like a house afire with .600 balls and one thickness of muslin or even .610 balls with the thinnest muslin I've found. Can't recall the thicknesses off the top of my head, but both are virtually re-usable, they stand up so well to firing.

Worth a try. If you can get to JoAnns or another fabric source with a micrometer, you should find a range of thicknesses to sample.

 

[paulvallandigham]

You can buy both .530" and .535" lead balls, swaged, or cast for reasonable prices, to try t find out what works best in your rifle.

Remeber that the reason to use a cloth or leather patch arond a RB in a Rifle serves Multiple fnctions:

1. Center the ball in the bore;
2. Seal gases behind the RB;
3. Transfer the rotation of the grooves in the bore to the RB, to impart spin to stabilize the ball in flight;
4. Carry grease or lube to act as a "firewall" to protect the soft lead ball from being cut or damaged in the bore by the burning gases;

and

5. To carry lube to grease the bore to soften carbon fouling in the bore after the shot is fired.

Using a smaller ball, and thin or inconsistent patching simply compromises one or more of these functions, IMHO.

Leave the .490 balls for use n your .50 cal. rifles. The .527" balls might be of use in the bore, but will require thicker patch material or double patching. The groove depth of your barrel should give you an indication of how thick your fabric should be. The Bore's Actual measured diameter will tell you what ball diameters will work best. With Muzzeloaders, everything else has been tried. You can tell this from other responses above.

In smoothbores, only the transferring of the twist of the rifling to impart spin to the ball is not done by that cloth patch. As these are short range guns when firing a RB, You can substitute smaller balls and other materials in a pinch and still get " minute of deer" accuracy to keep from starving. :hmm: :thumbsup: :hatsoff:

 

[Lonegun1894]

Brown Bear,
I have not tried muslin yet, but it is on the list now that you suggested it. Thank you.

Flash Pan Dan,
You're absolutely right about Roundball and his experiments being appreciated. I have been reading a lot of his older posts for quite some time in part due to his having had and used the same model GM .54 smooth barrels on his TCs that I am now using on my GPR.

Paul,
With all the posts on this forum regarding using various wads in order to protect thin patches in rifles, I was working under the assumption that the leather wad would protect the patch, and I tend to pick them up to read them (and clean my mess) and they look like they could easily be used again, so the leather must be working. I do think you may be right about forgetting the .490s for this smoothbore use, especially since I have molds for the proper size balls. I just thought this would be a interesting experiment. I will still keep playing with it and report if I get any decent results, but this isn't something I am seriously pursuing or have my heart set on.

 

[Ken Rummer]

I read your post and rushed to JoAnns. The lady I talked to said she never heard of it. I looked over their muslin selection and bought a yard of what they had. On the way home I stopped at a Super Walmart and found it in stock.

The JoAnns material was .008 to .0085 thick and I could see thru it. The Super Muslin was .0095 to .010 and I could only note light and dark areas. The slightly thicker material was a much tighter weave.

Thanks for the recommendation of this product. This looks like a better patch, in thickness and strength, for my GM 62 SB.

 

[roundball]

Have you tried muslin? It can get real thin, and especially the Super Muslin is tuffer than tuff.

First hand experience at it's best !

 

[tg]

One thing to consider abput the "sealing" the bore with patches with smootbore and balls is that very often with the right combo folks get very good results with an undersize bare ball and wadding of some sort to hold the ball in place and maybre under the ball as well, I get about a 4" group at 45-50 yds with a .55 ball and Tow wadding above and beliw in my .58 fusil, just reminding that smootbore can have a lot of options that work well once you find the ones for your gun. Not that it is an issue as such but it seems that patches were pretty rare with balls and smoothbores in the 18th century but they must have had some what acceptable accuracy as they did the job for a long time untill the rifled bore and PRB doubled or tripled the effective range of longarms.Siome do shoot a lot further but most settle for a 40-50 yd outside range with these guns, I know a couple of older fellas that could hold their own on a rifle trail walk with their NW guns evry time.

 

[Lonegun1894]

Brown Bear,
My pay just got deposited, so I'm off to Joanne's with my calipers. It's ok, they know what I'm doing and why, but the new girls always look at me funny while the older ones just say hi and leave me alone cause they already know. I think one of them actually understands, which was a surprize the first time we talked.