GPR question

[Smoke Rookie]

Could someone tell me what the "clean out screw" is for on my Lyman GPR? It's the little allen wrench screw below and on the side of the nipple. A friend of mine used it to put powder through it when a cleaning jag came off in my barrel, so we could shoot it out, but what is the purpose of it? Assuming that it is the clean out screw. When I clean my barrel, I always take the nipple out, but should I be taking this screw out for somthing? Thanks for the help, and oh yeah, does anyone know what size allen wrench works for it?

Brandon

 

[jtmattison]

Can't tell you offhand what size allen wrench it takes. I just keep the proper sized one in my shooting box all the time.
I would recommend always removing the cleanout screw when you clean your barrel. It opens up the breech more allowing you to get a good flow of water (if that's what you use) in and out of there.
Use an anti-sieze grease on the screw as you do the nipple so it doesn't get locked in place.
Another thing I recommend is installing the nipple first and then installing the cleanout screw, and when you take it out always remove the cleanout screw first. This will eliminate the possibility of marring the threads on the nipple because the cleanout screw makes contact with the nipple threads.
Hope this helps.

Huntin

 

[BrownBear]

I agree with Huntin all around. It seems almost as though the Allen screw works as a "set" screw for the nipple when used as he recommends. As for the right Allen wrench, the larger of the two Allen wrenches available from RCBS with the green plastic handle for use on reloading dies is a perfect fit. May be a little more expensive, but it's sure a lot harder to lose on the ground or in the bottom of a range box, much less down the kitchen sink.

 

I hunted and shot competition, with GPRs for probly 20+ years and after 'bout 4 or 5 years I quit remove'n tha "cleanout screw" all together. I never did use tha liddle cleanout hole fer anythin, I always jest removed tha nipple and dribbled a liddle FFFFG in to blow out a dry ball.

Yes they will act as a "set screw" fer tha nipple, but a stroke with'a file will short'n them enuff thet you can screw'em in proper and they won't lock tha nipple.

Lots of fellas have broke'n an "ear" off tha old "cleanout" screws thet was of tha old screwdriver slot type ('fore Investarms started use'n allen heads), and continued shoot'em without ever remove'n tha screw for many years.

I personaly think tha "cleanout screw" is a cure fer'a problem thet never existed in tha first place. :imo: :m2c: :results:

YMHS
rollingb

 

[REX]

The allen wrench size is a 2MM. Like others said, removeing it helps with cleaning.
rex (westcoastBPgramps)
bp cam be fun

 

[crockett]

The clean out screw is for cleaning out the drum. When you swab a bore some of the crude gets pushed down and gets in the channel between the drum and the bore. By removing the clean out screw and using a pipe cleaner you can clean out this area.
The allen head screw is probably used to make the area look more like the snail found on original Hawken type rifles. It may be possible to replace this screw with a standard type that could make removal easier but I would talk to Lyman about this.
On a misfire you really ought to get one of the CO 2 type ball dispensers. Much safer. If you have to prime the drum it is usually done through the nipple(DIXIE GUN WORKS sells an item for this) or you can remove the nipple and put in a little powder. I have done it both ways and the CO 2 is definately the better, safer option.

 

[Zonie]

:imo:It isn't really a cleanout hole.
There are two common ways to connect the nipple hole with the bore of the gun.

One used by many military guns and some guns with patent breeches is to drill the hole at a angle so that it intersects the bore or the powder chamber inside of the patent breech and the nipple hole. Guns using this method usually do not have (or need) the "cleanout plug screw) because there is no extra hole connecting the bore with the outside world.

If this method is used with a patent breech, it can be drilled from the powder chamber to the nipple hole.
If the gun does not have a seperate breech, it us usually drilled from the nipple hole to the guns bore.
This is fine on the military guns which have large diameter nipple threads, but is not easily done when the nipple thread is just a 1/4 thread.

Another way is to drill a hole straight thru the side of the breech block to the powder chamber, or thru the drum and then drill and thread the nipple hole so that it intersects this smaller hole.
If this method is used, something has to plug up the connecting hole at the outer end, and the easiest way to do this is to thread it and install a screw.

A third way of connecting the guns bore with the nipple hole is to drill the small hole all the way thru the barrel from the side opposite the nipple to the nipple hole. This hole is then plugged on the left side with a screw or a brazed in plug.
The only reason for using this design IMO is it doesn't "clutter" up the area around the nipple with unattractive screw heads.

As many have found, this "cleanout hole" can be handy. If you dry-load your gun, it is real handy to be able to just remove the screw and dribble enough powder into the barrel thru the hole to fire the ball out. If you use it for that, be sure and reinstall the screw firmly. Failing to retighten the screw can result in the unexpected loss of the screw, not to mention the irritated guy 2 benches down with a bloody knot forming on the side of his head. ::

Although a lot of people use the hole when they are cleaning their gun, I've found it unnecessary. Just removing the nipple and pumping lots of water thru the channel by placing the breech of the barrel in a bucket of water and using the cleaning rod/jag as a piston flushes all of the fouling out of this area.

 

[Smoke Rookie]

Thanks for the help fellas. I'll probably just keep pulling my nipple out for cleaning, till I get around to getting a set of allen wrenches. I'm sure I will, but after reading, I won't make it a rush on getting them. I always pull my nipple off after shooting anyway, and clean it while I'm cleaning my barrel, so no big deal there. Thanks for the help to all.
Another question I have has to do with the nipple on my GPR. I usually buy all my gear online through The Possible Shop. On there they have listed 2 different nipples. One says 6x.75mm for a Lyman and the other says (6 -.75). Are these the same size and will they both fit? I figure they are, but then again I am a rookie, and don't know a whole hell of a lot. Thanks again to all.
brandon

 

[Dave K]

Oh My GOSH! I have never removed either the clean out screw or the nipple for cleaning the gun! I just remove the barrel and fill it with water and force much of the cruds out the nipple, after I have the water running clear from the muzzle when I turn the barrel over. Saves the threads and I have never had a problem in 25yrs. Of course I wipe the bore and barrel dry and oil it when done. I also will wipe and oiled(Ballistol) patch down the barrel for about 3 days afterwards just for safety sake. Never a problem.

 

[harryo]

Oh My GOSH! I have never removed either the clean out screw or the nipple for cleaning the gun! I just remove the barrel and fill it with water and force much of the cruds out the nipple, after I have the water running clear from the muzzle when I turn the barrel over. Saves the threads and I have never had a problem in 25yrs. Of course I wipe the bore and barrel dry and oil it when done. I also will wipe and oiled(Ballistol) patch down the barrel for about 3 days afterwards just for safety sake. Never a problem.

I hope you are able to remove the nipple when you have to replace it. I am astonished that you haven't had to replace a worn out nipple for 25 years.

 

[crockett]

Probably the best thing to do is clean the gun in the normal manner with hot soapy water. When the water runs clear take out the screw and run a pipe cleaner through into the bore. If the pipe cleaner comes out clean-no problem, that's the way to clean the bore. If the pipe clean comes out fouled, then consider that as an extra step in cleaning the gun. Good luck.

 

[Dave K]

Oh, I have replaced my nipple, but I didn't remove it to clean it.Your mileage may very, but I have seen more threads ruined where the nipple screws in by always removing them then by just cleaning and oiling. Yes, I also shoot old guns and these old nipples have not been removed for cleaning either. I am talking of guns made from around 1840's and newer, the newer ones are shotguns.When I have removed a nipple for what ever reason, they were always clean as well as the drum. I always think if these guns were always unthreaded and put back together again all the time, they would not have survived till today.Oh, I don't remove my vents on the flinters either. But, shine or drop a light down the bore and all you will see is a shiny bore and a shiny vent.

 

[Maynerd62411]

Smoke Rookie: 6 X .75mm and 6-.75 would mean the same thing. Watch for the heighth difference in different brands of nipples. Lyman brand is a little shorter than Knight redhot nipple.

 

[harryo]

Oh, I have replaced my nipple, but I didn't remove it to clean it.

My apologies. I misread your post and took it to read that you hadn't removed a nipple in 25 years.