Ducere Insanus
HAM Plinker
Last edited:
I purchased the rifle back in June and overall for the price point I have been very happy with it. Been lurking and reading about everyone's experience with the 250z and just wanted to share my thoughts on my gen 1 250z. I welcome any opinions or advice...
Inspection of the barrel shows a machining gouge to the rifling about 7mm into the chamber. I assume this was the pilot of the bit that cut the chamber chamfer. The gouge is not uniforms as about 30% of the rifling is undamaged...30% however is fairly deep. It's like the rifling is smeared and wider on several lands.
Slugging the barrel shows significant difference of engagement the lands have on the bearing surface of the projectile when comparing one side to the other. I believe I also received one of the few choked barrels. The push down the barrel is very uniform but loose once past the chamber then it tightens up for the last 5 inches or so.
I ported/polished the thimble and transfer port to 4.4mm(should have tried 4.2 first). Barrel has been moderately polished throughout but heavily polished in the chamber area....crown is beautiful.
The stock spring cranked all the way in with the slug power weight can be tuned to same accuracy but I haven't dialed in which is most efficient however I believe no weight is best.
The rifle loves the 21.9 AEA and 28.5 JSB redesign. Both shoot 10 shot dime size groups at 50 yards at 920-1000fps and 875-925fps respectively. This works for me as the same tune and both pellets love to be pushed at the top of those fps ranges
Using a pellet gauge on about 20 different pellets from 18.1-28.5 grains I've discovered the the rifle really only likes pellets with a larger head diameter. The AEA 21.9 is 5.59 or larger and the JSB 5.56-5.57. The pellet gauge stops at 5.58 but the AEA's are the only pellets I've encountered this large
Slugs I've tried: JSB KO 25gr MK1 and MK2 .216
H&N hp2 .217 in 21/23/25/27 gr
Zan .217 in 20/23/25.5/28 gr
NSA .217 in 24.8 gr
NSA .2175 in 20.2/23.0/24.8
NSA .218 in 20.2/23.0/24.8/27.5
FX Hybrid 22gr(.217)
NSA .218 23gr/24.8 and FX slugs performed best but the groupings are very inconsistent shooting 1.5 inches to 2 inches 5-10 shot groups. Sometimes it will stack 2-3 shots however the amount of fliers does not justify using slugs over pellets.
I could never get a slug to shoot well. This of course is a budget rifle and I figured it would be a journey but I would eventually find the tune for the right slug. I have since come to the conclusion that there isn't a magic slug that ignores the barrel damage lol
I just reached out to Barra and they have offered a factory warranty replacement barrel and for that I'm grateful. However I cannot justify giving up a barrel that shoots so darn good with 2 different pellets on the same tune. The customer service assured me that they would inspect and send me a barrel with no damage.
Inspection of the barrel shows a machining gouge to the rifling about 7mm into the chamber. I assume this was the pilot of the bit that cut the chamber chamfer. The gouge is not uniforms as about 30% of the rifling is undamaged...30% however is fairly deep. It's like the rifling is smeared and wider on several lands.
Slugging the barrel shows significant difference of engagement the lands have on the bearing surface of the projectile when comparing one side to the other. I believe I also received one of the few choked barrels. The push down the barrel is very uniform but loose once past the chamber then it tightens up for the last 5 inches or so.
I ported/polished the thimble and transfer port to 4.4mm(should have tried 4.2 first). Barrel has been moderately polished throughout but heavily polished in the chamber area....crown is beautiful.
The stock spring cranked all the way in with the slug power weight can be tuned to same accuracy but I haven't dialed in which is most efficient however I believe no weight is best.
The rifle loves the 21.9 AEA and 28.5 JSB redesign. Both shoot 10 shot dime size groups at 50 yards at 920-1000fps and 875-925fps respectively. This works for me as the same tune and both pellets love to be pushed at the top of those fps ranges
Using a pellet gauge on about 20 different pellets from 18.1-28.5 grains I've discovered the the rifle really only likes pellets with a larger head diameter. The AEA 21.9 is 5.59 or larger and the JSB 5.56-5.57. The pellet gauge stops at 5.58 but the AEA's are the only pellets I've encountered this large
Slugs I've tried: JSB KO 25gr MK1 and MK2 .216
H&N hp2 .217 in 21/23/25/27 gr
Zan .217 in 20/23/25.5/28 gr
NSA .217 in 24.8 gr
NSA .2175 in 20.2/23.0/24.8
NSA .218 in 20.2/23.0/24.8/27.5
FX Hybrid 22gr(.217)
NSA .218 23gr/24.8 and FX slugs performed best but the groupings are very inconsistent shooting 1.5 inches to 2 inches 5-10 shot groups. Sometimes it will stack 2-3 shots however the amount of fliers does not justify using slugs over pellets.
I could never get a slug to shoot well. This of course is a budget rifle and I figured it would be a journey but I would eventually find the tune for the right slug. I have since come to the conclusion that there isn't a magic slug that ignores the barrel damage lol
I just reached out to Barra and they have offered a factory warranty replacement barrel and for that I'm grateful. However I cannot justify giving up a barrel that shoots so darn good with 2 different pellets on the same tune. The customer service assured me that they would inspect and send me a barrel with no damage.
