GPR LH

[REX]

I just received the new GPR, and was giving it a good cleaning and it looks like the nipple hole won't let any flash through, a #70 drill will pass through. Now for the question from the gramps that I've not seen the answer to yet. :: On the flint you can inlarged the flash hole for better operation, is this recommended on cap locks.
I thank the experts for thier help.

rex (westcoastBPgramps)
bp can be fun

post scrip: I now have one each(cap and flint)

 

The hole in the nipple is robably OK the way it is. If you enlarge it, too much gas pressure & flames can come back out the nipple, enlarging it from wear sooner, and can be dangerous in the amount of cap fragments it makes fly around your shiny eyeball. It really gets bad when the hammer is forced backup to 1/2 cock.
Daryl

 

[Zonie]

West Coast: The hole size you describe sounds about right for a percussion lock nipple.

To save others the time of looking it up, the #70 drill is .028 diameter.

Before altering it, I would try it out. If you are getting a lot of mis-fires then you might enlarge it but I don't think going over .032 would be a good idea for the reasons Daryl mentioned.
Actually, I think before enlarging it I would first try a hot cap like the CCI Magnum or RWS.

 

I'll side with Daryl here,,I don't have the GPR but I do own a Cabelas which is made by Lyman and the stock nipple supplied isn't the best available.
Nipples ware-out from what's called gas-cutting, a small amount of pressure is forced backwards thru that small nipple hole each tyme you fire, I've found after about 100 shot's or so the hammer starts to come back too half cock,,now thats not so bad, but what happens is more and more pressure comes backward instead of pushing your projectile and all of a sudden your groups fall apart!
I've found switching to CCI mag caps (RWS are top's too!), and using Uncle Mikes "HotShot" or Knights "Red Hot" nipples greatly improve reliable ignition.
Lyman rifles use a 6mm x .75mm nip. Also, be sure to clean even new nipps really well to remove any "oils" from manufacture,nipples gotta be about the toughest part of BP guns for me to clean,,I use a small brass brush and pipe-cleaners,but when yer all THUMBS like me!!,!

 

[gordy]

It seems that many of the stock nipples fail to give good ignition.Both on this Forum and on the CVA forum, most shooters change to the hotter nipples,I have one on the Renegade (Hot Shot) and have never had a hang or misfire after putting it in.The stock nipple "might"work OK as is give it a try. /ubbthreads/images/graemlins/cool.gif

 

[Maynerd62411]

One problem with the Knight's "red hot" nipple is the height. They stand up a little too tall on my son's Lyman Deerstalker. The main reason for not using the original Lyman nipple was the problem of the cap falling off when the barrel was pointed up. It seemed like an easy fix , at the time.

 

Good point DavidS,,another thing I have seen is some manufatuers of after market nipps have the thread casing too long! Beit drum or snail the area ahead of the nipple hole is only so deep,,if the threads go too deep then thars not much room for the flash to contact the main charge!

Gramps,,another tip just the opposite of flinters! Is to be sure some of the main charge is in the breech channel,,(no feather needed here) pour the main charge then "rap" the nipple side of the stock a bit,,then patch-n-ball,,in the case of cappers we NEED the cap's "fire" to iginte the main charge

 

[REX]

Thanks guys for all the helpful information. :applause: I had to ask the question after reloading center fire for so long, when I compared the primer hole to the nipple hole, it look to small to let the flash through. If one had a lathe(i've got one), could you modify the red hot or any other nipple that is 6X.75 to work in the GPR (not that I'm a machinist), or do you do the smart thing and just replace using the stainless steel nipples? :: Like the sayings go "better safe then sorry" and " keep it simple stupid".
Thanks again, I;m sure the more I shoot BP the more Questions I'll have.

rex (westcoastBPgramps)
bp can be fun

 

a friend of mine "grump" got some of those stainless steel nipp's fer his .50 GPR from track, and they've been working fine for him. He don't shoot a whole lot like i do( an I only shoot about 8 pounds a season),,but it stands ta reason that they'd take alot more a that gas cutting I mentioned.
I think alot of the "hot" type nipples we'er talkin about has to do with the shape of the "flash chamber" or neck and some of the "coning" they do around the hole it's self that they've done to improve it.
I do know the pro's that shoot that 1000m stuff use titanium inserts,,not beacause of big loads,they usually shoot 80-90 grs,,but because it doesn't burn,,it stay's the same,,
luck too ya,,best wishes,,,

 

BPgramps.
Be advised that Lyman uses a nipple peculiar to Lyman. Other nipples WILL NOT work. I went thru this thinking just because the thread size was right the Uncle Mikes would work. THEY WILL NOT!
You can order nipples direct from Lyman if you can't find them anywhere else.
DO NOT enlarge the nipple hole.
This absolutely will allow too much gas blowback out the nipple hole.
Now for you guys that are getting away with using the Uncle Mikes or other nipples for the Lyamn...well go ahead, but :shocking: :no: :no: it ain't right!