Lyman GPR part 3

[flyfish]

A while back I was all excited about getting the Lyman Great Plains Hunter. It came but couldn't get it together. The wedges would not go in. There was about 1/16 inch interference. I got some suggestions here on this sight and similar ideas from Lyman. None worked so they told me to send them the rifle. I did and finally got it back ( that's another story). It does go together but not as smoothly or the way I expected it to. I cleaned it all up and took it out to make it go bang. It did go bang and I hit low. So I tried turning the screw on the rear sight. The screw would budge! I tried a couple different screw drivers and I either bent the blade on the screw driver or took chunks of metal off the blade :cursing: . I like the rifle but it just seems that this gun and I are having some issues :surrender: I will email Lyman tomorrow and see if they will send me a new sight. I really didn't expect I would have these issues with a gun in this price range. Am I just :youcrazy: or what?

On a positive note...... My buddies and I took a walk up to our deer camp to check it out after a long winter. I brought my GPH for them to see and shoot. Robert shot first. I told him it was shooting low and he compensated and hit the plasic cup he was shooting at. He liked the way it shouldered and shot. Then Doug took a shot and missed. Then they wanted me to shoot. I barked the tree right next to the cup which sent the cup flying. On the way back down the hill my golden retriever went running after something. A red squirrel went up a tree. We looked at each other and someone said, got any more ammo? I said yup! So I loaded the gun up and took a shot. Well the red squirrel came out of the tree. I have to say, a 50cal round ball is a little course for squirrel shooting :shocked2: But I got first blood with the gun. Soooooo, once I get the sight problem fixed I'm hoping to do some more shooting and go after some woodchucks in about a month. That's if winter ever decides to leave. Then of course some deer hunting :grin: (this fall).

If anyone has any thoughts on how to get the screw loose on the rear sight I'd love to hear it.
Oh, yea, thanks for letting me vent.

 

[Zonie]

ALL of the Great Plains rifles are intentionally shipped with a front sight that is too tall.

There is a fair chance that your adjustable rear sight is adjusted as high as it will go. Some adjustable sights are made so that they cannot be adjusted beyond a certain height.
Have you tried lowering your rear sight?

If the rear sight will allow you to adjust it lower that is the first step in sighting in your new rifle. Crank it down about half way between where it is now and the lowest setting.

Once this is done, now is the time to start shooting to really sight in the gun,

Start at 25 yards and using the center of the bullseye as a target location fire at least 3 shots. They will all hit low so it's a good idea to post the target on a piece of cardboard that hangs way below the target.

Measure the distance from the center of the group to the center of the bullseye.

Now, get out your calculator.
The front sight will have to be filed DOWN .024 to raise the group 1 inch (at 25 yards distance).
.024 is a little less than 1/32".

Using this .024 value, if the middle of the group is 3 inches low at 25 yards you will need to remove 3 times .024 or .073 from the front sight.
That is just a bit more than 1/16" of material removed.

After you have filed off the front sight and your group is now centered at 25 yards, move the target to 50 yards and repeat shooting at least 3 shots. 5 is better.
Measure the distance from the 50 yard group to the center of the bullseye.
At this new range you will have to remove .012 of material from the front sight to raise the group 1 inch. .012 is just about 1/64"

Lets say the group is now 2 inches low. 2 inches times .012 is .024 so you will need to remove just a bit less than 1/32" from the front sight.
There is another option for you now.

Remember when I suggested that you move the rear sight to about the middle of its range? Now is the time you can make use of that. Moving the rear sight UP .024 will have the same effect as filing .024 off of the front sight so moving it will also raise your group to center.

If you plan on doing most of your shooting at 100 yards I recommend that you file the .024 (or whatever it calculates to be) off of the front sight at this 50 yard range saving your rear sight adjustment for dialing in your group when you start shooting at the longer distance.

Have fun.

 

[flyfish]

Zonie,

Thanks for the info. Very helpful.

The screw doesn't turn in either direction.

 

[William O.]

I personally hate the adjustable sight and just swap it out with the primative fixed sight that Lyman includes with their rifles. I did have to file a bit off the front sight as well.

 

[Sinner]

I personally hate the adjustable sight and just swap it out with the primative fixed sight that Lyman includes with their rifles. I did have to file a bit off the front sight as well.

I have a GPR in .54 that I just finished from a kit. I shot it the other day for the first time. It too, shot low. I have the primitive rear sight and had to file the front down. I would suggest the primitive rear and filing the front as well! I really like the looks of the primitive sight, and will shoot it enough to know how much to compensate for various ranges.
I guess that doesn't answer the original question though! You may want to try a drop of kroil oil on the screw, let it penetrate a few minutes, and then try the screw again.

 

[jethro224]

Great information from Zonie. :thumbsup:
Even better idea from Bull3540. :thumbsup: :thumbsup:

 

[Prairieofthedog]

Fly,sorry to hear about your problems with your GPH.I just got my GPR kit in the mail Friday.All set to start working on it and discovered a 1 3/4" crack in the bottom of the forearm.It wasn't from shipping it just looked like it dried out and cracked.I'm going to try and send it back and they should replace it.What procedure did you go thru to send your gun back.Thanks

 

[flyfish]

After reading bull3540 post I went down stairs and removed the rear sight. After doing so I believe I found out why the screw wouldn't turn.
It appears that the adjustment screw was bottomed out causing a thread to stick out below the bottom of the sight. So when the sight was "hammered" on to the barrel the thread cut a sliver of metal off the barrel which went inbetween the threads and not allowing the screw to turn. I tried putting the other sight on the rifle but it slide right through the dovetail with no resistance what so ever :cursing:

Prairieofthedog,
I would think it would depend who you bought the gun from. I bought my through Cabela's and I'm sure they would take it back no questions asked.
What I did was to call Lyman's Customer Service people and tell them what happened. I ended up talking with a guy in their Lab and he told me to send it them. He did ask me where I bought it.
Lyman's customer service number is 1-800-225-9626

 

[jbtusa]

Concur: I also put the factory rear primitive sight on my GPR. The adjustable rear sight looks cheesy and the primitive sight looks more period correct. I love it and it is accurate! (If the primitive sight is loose, use a hammer to ping down the edges of the dovetail so that it stays put.)

Also, shoot the GPR/GPH at least 100 shots to settle the barrel, then they become amazing rifles.

 

[flyfish]

I sure hope so (being a good shooter). I love the feel and the looks of this gun. If I can just get by this rough patch. Hope to get out soon and do some target shooting.

 

[Jim Fitzgibbon]

On my fixed sight I took a center punch & punched
down in the dove tale of the barrel & on the bottom of the sight to tighten it up.

Remember it easy to file metal off the front sight
to lower it.But putting back to make it taller
involves welding.

I have not filed mine just yet.That will be the last thing I do till I get the right powder charge
& bullet patch size that this gun likes.

I'm just working on groups right now.Once I get
what suits this rifle, I will then worry about
filling the front sight down.

Mine as of now seems to be shooting 2" low.Remember to take it slow when fileing.
As on mine .024 is not alot.The hair on your
head is about .003 thick.Just take your time
as I'm & you will have a very fine shooting gun.

Fly :thumbsup:

 

[flyfish]

:grin: :grin: Yup, I looking forward to it.

Thanks all for the help and info, you are all a great resource :hatsoff:

 

[richard peterson]

If you keep the adjustable rear sight on the rifle and finally get it shooting the way you like, I suggest putting a small wooden wedge under the sight(like a matchstick) to keep things locked in and secure. The only thing keeping tension on the adjustment screw is that weak little spring. It is easy for the screw to back off or fall out otherwise.

 

[boar]

What I do is put the sight you say is to big in a small clamp and put the clamp in a vise and shine the base good and flux it, then put solder on base,cover all of it. You can smooth it up with a file, then tap it in. Usually the solder will shave of. Makes for a good fit usually. I like this better then the dimple method. The reason you use a clamp instead of just putting the sight in the vise is the vise will take away your heat and make it hard to get the solder to stick. Have fixed several this way. Dilly

 

[flyfish]

INTERESTING! This thought actually crossed my mind last night but was not sure if I could make the solder stick and it was too late for me to be playing with fire :shocked2: :grin: :grin:

 

[Sinner]

I tried putting the other sight on the rifle but it slide right through the dovetail with no resistance what so ever :cursing:

Take a center punch and create a "crater" in the bottom of the dove-tail slot. That will hold your primitive sight in place tightly!