Lyman Great Plains Rifle Question

[Whiteeagle58]

I just picked up a Lyman Great Plains Rifle in .50 caliber. The guy I bought it from got it as part of an estate, and he told me that the previous owner put it together from a kit, according to his wife. This makes sense to me, as all of the steel furniture and barrel have been nicely browned, and I thought the factory guns were blued. Anyhow, there are no warning stampings on the barrel, and I can't find any Italian proof markings. The only markings are "GREAT PLAINS RIFLE .50" on the right side, and the serial number 423xxx on the left. Any ideas/thoughts on the age/date of manufacture? Other than needing a good cleaning of old dried grease and light surface rust, the rifle is in very good condition, and was nicely assembled. Thanks in advance for any help!

 

[Phil Coffins]

Some of us will draw file off some or all of the stampings on a muzzleloader for no other reason than we think it looks better. That could well be what happened to yours. None of the stampings are required.

 

[TreeMan]

Yep as Phil said. The fella that built it removed the dictionary of warnings prior to browning the barrel. If the date code is gone you’ll never know. Doesn’t really matter because they are all the same. All Great Plains rifles were built by Investarm. Investarm still makes them today branded as Gemmer Hawkens. Lyman was just an importer.

 

[Whiteeagle58]

Thanks for the replies! I kinda' wondered if that was the case. Certainly looks better this way!

 

[longcruise]

Have you looked at the underside of the barrel.

 

[Whiteeagle58]

Have you looked at the underside of the barrel.

I have, and there are no markings of any kind there.

 

[William Sublette]

I think, (I don't know), the the earlier models had a solid under rib.

A some point they started putting a notch in the under rib, with a little bent piece of spring type metal to put pressure on the ram rod. Help it stay in place.


I may be wrong.

 

[Whiteeagle58]

I think, (I don't know), the the earlier models had a solid under rib.

A some point they started putting a notch in the under rib, with a little bent piece of spring type metal to put pressure on the ram rod. Help it stay in place.


I may be wrong.

Mine has the notched rib with spring.

 

[Jedidiah]

I just picked up a Lyman Great Plains Rifle in .50 caliber. The guy I bought it from got it as part of an estate, and he told me that the previous owner put it together from a kit, according to his wife. This makes sense to me, as all of the steel furniture and barrel have been nicely browned, and I thought the factory guns were blued. Anyhow, there are no warning stampings on the barrel, and I can't find any Italian proof markings. The only markings are "GREAT PLAINS RIFLE .50" on the right side, and the serial number 423xxx on the left. Any ideas/thoughts on the age/date of manufacture? Other than needing a good cleaning of old dried grease and light surface rust, the rifle is in very good condition, and was nicely assembled. Thanks in advance for any help!

Mine has a ser #that is A 4832XXX...made in 2000,so your would be before that. IMHO. also has a screw on rib and the metal ram rod retaining spring. I alos have a 2022 Gemmer GPR. It is identical to the other one (Lyman Investarms) however, the orig Lyman one had better metal castings etc that required less work to clean up then Gemmer one. I also draw filed the Gemmer to remove tht multitude of writing on the barrel and left only the name Gemmer, ser # and caliber.

 

[longcruise]

The Italian made barrels all seem to have proof marks and maker ID. Maybe it is American made? If filed off there should be easily seen variation in the width of the flats.

 

[Jedidiah]

The Italian made barrels all seem to have proof marks and maker ID. Maybe it is American made? If filed off there should be easily seen variation in the width of the flats.

If you draw file properly it is extremely difficult to tell. Tap the engraved/printed writing with a punch so it kind of fills in before you draw file. Slow and easy, nice flat strokes, decent file, No problem. it took me less than an hour to do it all especially once you refinish it, ie Brown or Blue it.

 

[longcruise]

If you draw file properly it is extremely difficult to tell. Tap the engraved/printed writing with a punch so it kind of fills in before you draw file. Slow and easy, nice flat strokes, decent file, No problem. it took me less than an hour to do it all especially once you refinish it, ie Brown or Blue it.

Given that, I vote draw filed or American barrel.

My only last suggestion: check the twist rate 1:48, 1:32 or 1:60 almost certainly Italian. Any other twist likely American.

 

[Whiteeagle58]

Given that, I vote draw filed or American barrel.

My only last suggestion: check the twist rate 1:48, 1:32 or 1:60 almost certainly Italian. Any other twist likely American.

Twist measures 1:60.

 

[longcruise]

That would be the later GPR twist. Early were 1:48 but I don't know what the date of the switch was.

 

[Jedidiah]

That would be the later GPR twist. Early were 1:48 but I don't know what the date of the switch was.

I thought that there was always two twists available. 1/48 for conical,sabots etc and 1/60 for PRB? My orig lyman is 2000 and it is 1/60....I have also heard that there was 1/66 but can't prove it>

 

[longcruise]

The Great Plains Hunter (GPH) was a 1:32 and was marketed for bullets. My first GPR was a circa 1981 and was a 1:48. Sometime between then and now they went to 1:60. My original GPR now has a GM 1:70 and the original barrel was part of a swap.

 

[2Moons]

I bought my .54 cal GPR kit in or around 1985. It has a 1:60 twist. Won’t shoot a maxi worth a darn, but with RB, is a tack driver.

 

[ETipp]

I bought my .54 cal GPR kit in or around 1985. It has a 1:60 twist. Won’t shoot a maxi worth a darn, but with RB, is a tack driver.

Same with mine.

 

[smokeum54]

I just picked up a Lyman Great Plains Rifle in .50 caliber. The guy I bought it from got it as part of an estate, and he told me that the previous owner put it together from a kit, according to his wife. This makes sense to me, as all of the steel furniture and barrel have been nicely browned, and I thought the factory guns were blued. Anyhow, there are no warning stampings on the barrel, and I can't find any Italian proof markings. The only markings are "GREAT PLAINS RIFLE .50" on the right side, and the serial number 423xxx on the left. Any ideas/thoughts on the age/date of manufacture? Other than needing a good cleaning of old dried grease and light surface rust, the rifle is in very good condition, and was nicely assembled. Thanks in advance for any help!

I have 2 gpr.
One date code 1980 ser # 121xxx
Second 1981 ser # 143xxx.
The 81 has the warning label.
Guessing yours is mid 80's

 

[David Austin]

Well...as to the 'warning'. My .54.GPR flinter kit didn't have one. But it was very early in the production...maybe 1978. Sent it to my son last year...I'm getting old...and fragile. I shot it with 120 g 3f...and I was afraid I'd shatter bones. I ended up with the .50 GPR kit...it's a chore...maple is so much easier to work than walnut. Took a week to clean up the poly coat on the forearm.