-
Friends, our 2nd Amendment rights are always under attack and the NRA has been a constant for decades in helping fight that fight.
We have partnered with the NRA to offer you a discount on membership and Muzzleloading Forum gets a small percentage too of each membership, so you are supporting both the NRA and us.
Use this link to sign up please; https://membership.nra.org/recruiters/join/XR045103
Lyman GPR PRB powder charge
- Thread starter MtnWolf
- Start date
Help Support Muzzleloading Forum:
I never had one of them, but I would start at around 65 grains of 3Fg and work it up by 5 grain increments until you find a charge that groups well. From there toy with the load by 1 grain increments up and down until you find the sweet spot. Adjust your sights after you find you group.
The .490 will shoot better with .018 or the .015 with the .495. It shoots light loads pretty well but it will start grouping real well at 75 grains and it will shoot 110 grains of 2F very well.
The manual has instructions on getting the cross pins tight. I would suggest snugging them up before sighting it in. I did not and had to buy a new front sight. I use the primitive rear sight that comes with it and thus filed the front sight for the correct sight picture.
I love mine and it shoots better than I can hold.
Nice rifle all around! Geo. T.
The manual has instructions on getting the cross pins tight. I would suggest snugging them up before sighting it in. I did not and had to buy a new front sight. I use the primitive rear sight that comes with it and thus filed the front sight for the correct sight picture.
I love mine and it shoots better than I can hold.
Nice rifle all around! Geo. T.
- Joined
- Jul 15, 2007
- Messages
- 1,994
- Reaction score
- 637
I'm right there with you MtnWolf. This arrived at my door today.
A "forum buddy" on Modern Muzzleloader picked it up and shipped it to me here in Louisiana (he's in Kansas). He spotted it in a mom & pop shop a few towns away from his home and got a real good deal on it. The story is it was sitting in their stock room for years. The date on the original Lyman box is 5/20/00.
So far as I can tell it's unfired except someone snapped a flint on the frizzen a few times. Looks to be a good sparker. It lit off the pan five times in a row for me with a new English flint.
A "forum buddy" on Modern Muzzleloader picked it up and shipped it to me here in Louisiana (he's in Kansas). He spotted it in a mom & pop shop a few towns away from his home and got a real good deal on it. The story is it was sitting in their stock room for years. The date on the original Lyman box is 5/20/00.
So far as I can tell it's unfired except someone snapped a flint on the frizzen a few times. Looks to be a good sparker. It lit off the pan five times in a row for me with a new English flint.
The comments about the fixed/rear sight above are good, I gave up on the adjustable one, clicks in elevation also gave me radom windage shifts - I don't have to worry about that with the fixed sight. My .54 likes 100 gr. of FFg, and beats me up during a long range session, but it will drive tacks if I do my part. Be sure to clean your new rifle well, Lyman/Investarms ships the rifle's bores well coated with a preservative. You will enjoy it more if you find some real black powder.
longcruise
70 Cal.
Ditto that!! :thumbsup:
I have three of those adjustable rear sights in my kit and have no use for them at all.
This sight from Track of the Wolf is nice if you like adjustable.
Adjustable rear sight
You might need to fiddle with the dove tail a bit but it's easy to do. On mine, Fit it kinda loose to the dovetail and then drilled and tapped it for a set screw to make windage adjustment easy.
will5a1 made a good point about these Lyman GPR's.
Whatever the factory coats the bore with to protect it is really difficult to remove.
If you try to "shoot it out" you'll go thru the better part of a box of roundballs before it starts to behave.
Get something that is really good at cutting grease and a lot of clean patches to get that stuff out before shooting it.
Automotive Disk Brake cleaner works pretty good as a solvent.
Whatever the factory coats the bore with to protect it is really difficult to remove.
If you try to "shoot it out" you'll go thru the better part of a box of roundballs before it starts to behave.
Get something that is really good at cutting grease and a lot of clean patches to get that stuff out before shooting it.
Automotive Disk Brake cleaner works pretty good as a solvent.
I've had pretty good luck with a .495 ball, .018 pillow ticking, 1/6 ballistol-water dry patch, and 60 grs of 3F in my GPR.
The Hungry Hunter
40 Cal.
- Joined
- May 13, 2008
- Messages
- 149
- Reaction score
- 0
I have the GPR(percussion) also 50 cal. I am using 75 grains goex 2f, .015 patch,.490 prb, TWF Mink oil, and I am getting 1-1/5 inch groups off of a rest at 50 yards, love the rifle.
Little Wattsy
69 Cal.
- Joined
- Jan 7, 2008
- Messages
- 3,631
- Reaction score
- 9
Cynthialee said:
Perzactly!! :thumbsup:
Billnpatti
Cannon
- Joined
- Aug 11, 2008
- Messages
- 7,340
- Reaction score
- 44
You won't know what your specific rifle will shoot until you have put a couple hundred rounds through it. When the rifling is new, the edges are sharp and need to be "shot in" to smooth them out. Then you will be ready to do some serious load development. For now, I'd stick to about 50 grains of 3f black powder. That will give you a good starting load. After you have put a couple hundred rounds through your bore, you will be ready for serious load development. While you are putting that couple hundred rounds through your new rifle, order a copy of Dutch Schultz' Muzzleloading Accuracy System. You can find him online. His "system" will cost you around $20 but you can't find a better way to spend $20 on your muzzleloading hobby. Follow his instructions to the letter and you will have your rifle shooting to its best accuracy. You will be amazed with the results.
BTW, my personal preference for a patching material is some stuff called "pocket drill". It is available in most fabric shops. Wash it before using it and do not use any fabric softener. The stuff measures around .018 and after washing it will be able to be crushed down as you load it to something around .010. Great stuff. My personal favorite patch lube is straight Ballistol. Just enough to dampen the patch is all you need. I have found it to be great about keeping fouling down. My favorite powder is Goex and I use 3f for all of my guns. It, too, is great stuff.
Oh yes, I almost forgot to add this. You can speed up your break-in of your bore by using something like valve lapping compound on a tight patch or steel wool wrapped around an undersize bore brush so that it fits tightly in your bore or even the green 3M scouring pad material used with a .45 cal jag. Just pick the method you like and polish away. Use some soapy water as a lubricant with either the steel wool or the 3M pad. You don't need to use a lubricant with the valve lapping compound because it has oil in it. Make about 100 strokes full length of the bore so that the polishing will be even from breach to muzzle. Also be absolutely sure to use a muzzle protector on your rod. You sure don't want to change your muzzle by letting a rod with an abrasive material on it rub on the muzzle as you polish your bore. This will polish the sharp edges off the rifling and achieve the desired effect that shooting a couple hundred rounds through your new bore will. Thoroughly wash out your bore to remove all abrasive material before re-oiling it to put it away
If you have any more questions, come on back because we all love to answer questions.
BTW, my personal preference for a patching material is some stuff called "pocket drill". It is available in most fabric shops. Wash it before using it and do not use any fabric softener. The stuff measures around .018 and after washing it will be able to be crushed down as you load it to something around .010. Great stuff. My personal favorite patch lube is straight Ballistol. Just enough to dampen the patch is all you need. I have found it to be great about keeping fouling down. My favorite powder is Goex and I use 3f for all of my guns. It, too, is great stuff.
Oh yes, I almost forgot to add this. You can speed up your break-in of your bore by using something like valve lapping compound on a tight patch or steel wool wrapped around an undersize bore brush so that it fits tightly in your bore or even the green 3M scouring pad material used with a .45 cal jag. Just pick the method you like and polish away. Use some soapy water as a lubricant with either the steel wool or the 3M pad. You don't need to use a lubricant with the valve lapping compound because it has oil in it. Make about 100 strokes full length of the bore so that the polishing will be even from breach to muzzle. Also be absolutely sure to use a muzzle protector on your rod. You sure don't want to change your muzzle by letting a rod with an abrasive material on it rub on the muzzle as you polish your bore. This will polish the sharp edges off the rifling and achieve the desired effect that shooting a couple hundred rounds through your new bore will. Thoroughly wash out your bore to remove all abrasive material before re-oiling it to put it away
If you have any more questions, come on back because we all love to answer questions.
- Joined
- Jan 3, 2004
- Messages
- 14,767
- Reaction score
- 319
MtnWolf said:
I shot a lot of Pyrodex in my 50 when I first got it. I had much better ignition and accuracy with P than with RS or Select. I had issues with the Lyman nipple and CCI caps, but changing the nipple fixed that. No prob with Remington or RWS caps and the Lyman nipple, though.
Lotta good advice here on initial bore cleaning, shooting break-in, patching. After a couple of hundred shots for break-in and load adjustment, you'll be real impressed with accuracy.
In my new to me Investarms Trade Rifle, maker of the Lyman, I found the 75 Goex 3 F load with a .490 ball, .15 ticking, lubed with bore butter to be a good load. On the next range trip I am going to bump it up in 5 grain increments to see what it does before I cut the rear sight to POA/I for a certain load.
Your patch/ball combo might not be tight enough. My GPR wanted .495s and .015s right out of the box, and after a few hundred rounds, needed .018s, and later, .020s. The general consensus seems to be that its pretty normal for GPRs to require thicker patches as they "shoot in" over that first year or two.
If you are going to use a bp substitute, give Triple Seven a hard look. The ease of cleaning alone makes it well worth the price.
If you are going to use a bp substitute, give Triple Seven a hard look. The ease of cleaning alone makes it well worth the price.
MtnWolf
32 Cal.
- Joined
- Dec 4, 2009
- Messages
- 26
- Reaction score
- 3
I had been shooting a CVA percussion Hawken in 50 cal for many years and never was real happy with the groupings. With all of the comments helping with the GPR you all have given me some thought and hope on how this CVA might become a better shooter.
AZbpBurner
54 Cal.
My new Flint .50 GPR does well with 70 Gr.3F, .018" patch around a .490" RB. Once it's properly broken in, I'll try incrementally lighter & heavier loads, but for now, 65-70 Gr. works for me.
I would start a little lower at 55 grains and a .018 patch lubed with your favorite. I use 100% cotton mattress ticking lubed with olive oil, both are cheap and easy to find. Shoot three shots and then increase by 5 grains until you get nice tight groups. Same advice on the sights, toss the adjustable one and go with the fixed. Tap it left or right to adjust point of impact and gently file the front sight down to raise it. (POI) New Lyman barrels most always need a final polishing via the various methods mentioned already, or you can just shoot it in. 100 shots or so will do it and you'll see the accuracy improve greatly. Lastly, toss the factory nipple and replace with a stainless steel example or my favorite, the Treso/AMPCO bronze nipple. Well worth the extra dollar or two in longevity and performance.MtnWolf said:
