gerpwaller
Well-Known Member
- Joined
- Dec 5, 2017
- Messages
- 73
Hi Guys,
I have a 308 with a 22" proof barrel on a tikka action bedded and floated in an Iota Eko stock. I'm having some issues with it that seem very strange to me. I will start off by saying getting a replacement barrel is likley not an option as I was gifted this barrel and it was pulled off a PGW build. My gunsmith (the same one who installed it on the pgw in the first place) then turned the barrel down so that it fit my action and cerakoted the metal on the barrel OD green to match the green in the stock. I am aware of the possibility that this extra work may have compromised the integrity of the barrel but the results are still confusing to me. The rifle that the barrel came off of had a very low round count and for indications was very accurate (3 different bullets shooting 5 round groups inside 0.75 moa). I realize that since Hornday's podcasts on group sizes that 5 rounds is statistically meaningless but there was no indication that it wasn't a shooter.
Shooting both 168 gr GMM and 168gr federal Terminal Ascent bullets the first 3 shots are inaccurate (group about 2.5 moa) before it settles in to do 10 and even 20 round groups inside 1.5". After seeing this trend a few times I decided to do a cold bore accuracy test shooting 2 shots at two different targets on different days. The 1st shot group is strung largely vertically but from about the 7:00 position to the 2:00 position shooting a 2.5" group after 7 cold bore shots. The second shot group is strung horizontally 2.5" with only about 1" vertical dispersion. Dispersion of both groups is realatively even so it's not like it's grouping well with the occasional flyer. After about 3 shots the rifle will group both loads into 1.5" or less. I have tested this 3 times. Twice doing 10 round groups and once finishing the box and doing a 17 round group all three of which were under 1.5 moa (one group was done at 360 yards the rest at a bench at 100 yards). This is what prompted me to do a cold bore test to see if I can expect it to be reliable hunting rifle. I've tried researching if anyone has seen similar issues with a proof barrel with no luck. I can't really complain much since I was gifted the barrel but it makes no sense to me, and is making my brain itch, why the barrel would seem to need a bit of heat in order to be accurate.
I've been shooting off of a sand bag with a sand bag for a rear support. I have other rifles that I can routinely shoot 10-20 groups into 1-1.5 moa so I know the issue isn't simply my shooting. I'm open to any theories as to why this might be the case. If the general consensus si that the barrel is pooched from the extra work needed to convert it to a tikka compatible barrel then so be it. It still doesn't explain why it shoots great when warmed up and terrible when cold.
Cheers,
Gary
I have a 308 with a 22" proof barrel on a tikka action bedded and floated in an Iota Eko stock. I'm having some issues with it that seem very strange to me. I will start off by saying getting a replacement barrel is likley not an option as I was gifted this barrel and it was pulled off a PGW build. My gunsmith (the same one who installed it on the pgw in the first place) then turned the barrel down so that it fit my action and cerakoted the metal on the barrel OD green to match the green in the stock. I am aware of the possibility that this extra work may have compromised the integrity of the barrel but the results are still confusing to me. The rifle that the barrel came off of had a very low round count and for indications was very accurate (3 different bullets shooting 5 round groups inside 0.75 moa). I realize that since Hornday's podcasts on group sizes that 5 rounds is statistically meaningless but there was no indication that it wasn't a shooter.
Shooting both 168 gr GMM and 168gr federal Terminal Ascent bullets the first 3 shots are inaccurate (group about 2.5 moa) before it settles in to do 10 and even 20 round groups inside 1.5". After seeing this trend a few times I decided to do a cold bore accuracy test shooting 2 shots at two different targets on different days. The 1st shot group is strung largely vertically but from about the 7:00 position to the 2:00 position shooting a 2.5" group after 7 cold bore shots. The second shot group is strung horizontally 2.5" with only about 1" vertical dispersion. Dispersion of both groups is realatively even so it's not like it's grouping well with the occasional flyer. After about 3 shots the rifle will group both loads into 1.5" or less. I have tested this 3 times. Twice doing 10 round groups and once finishing the box and doing a 17 round group all three of which were under 1.5 moa (one group was done at 360 yards the rest at a bench at 100 yards). This is what prompted me to do a cold bore test to see if I can expect it to be reliable hunting rifle. I've tried researching if anyone has seen similar issues with a proof barrel with no luck. I can't really complain much since I was gifted the barrel but it makes no sense to me, and is making my brain itch, why the barrel would seem to need a bit of heat in order to be accurate.
I've been shooting off of a sand bag with a sand bag for a rear support. I have other rifles that I can routinely shoot 10-20 groups into 1-1.5 moa so I know the issue isn't simply my shooting. I'm open to any theories as to why this might be the case. If the general consensus si that the barrel is pooched from the extra work needed to convert it to a tikka compatible barrel then so be it. It still doesn't explain why it shoots great when warmed up and terrible when cold.
Cheers,
Gary
