6BR throat wear ?

[SDWhirlwind]

Hope this is where I ask this. Built me a 6BR a few years back for shooting pdogs. Krieger 14twist barrel. The load I shoot is 65Vmax with 30.5gr of 2015BR from a 26" barrel. Was getting ready to load some rounds tonight and thought I would measure OAL as I hadn't done it since I built it and found OAL for the 65Vmax. Rifle has 1036rds down it since new. I usually only shoot 10rds at a string with the HV Krieger before I let it cool. A handfull of times I have went as many as 15rds if things were a bit slower and I had some time between shots.

So if my getting forgettfull mind is working right I have about .030 throat wear since new? For you 6BR guys does that seem about normal for the round count? Usually never paid much attention with throat wear when I shot factory barrels as long as they were still shooting descent and never kept real accurate data on round count as most I bought and shot were used rigs. This was the first 'real' varmint rig I built myself and have tried to baby it. Guess it kinda caught me off guard as I thought .030 was/is a bit excessive for just over 1K rounds????

Normal or Not Normal???

Thanks for this forum.
Respectfully,
Dennis

 

[Raptor]

Dennis,
What you might be experiencing is a common thing that happens after a fresh chambering. Many times the start of the throat may not be as sharp as it will be after firing some rounds down the new barrel.

Guys will check it as a brand new rifle and then check it later on after they have put a couple of hundred rounds through it and find the throat has moved forward a lot more than antisipated.

In reality the throat has not really moved much at all its just the slight edge that may have been left by your reamer has been "Smoothed" up. You may put another 1000rds through it like you have been and find hardly any movment at all.

 

[SDWhirlwind]

Thanks Raptor. Makes sense.

I usually buy a sleeve of 500 at a time but loaded and shot them all and wasn't smart enough to measure the new lot to see if Hornady might have made a minor change to profile of ogive etc.

Kinda like a bunch of older Sierra 60 HP I bought a few years ago for about 1/2 of new now. Anyway went to load some couple days ago for my 6TCU and find that of the older cardboard boxes there is at least 3 different ogive differences in 6 boxes??? About .008 and .014 difference from what I had loaded and shot prior. Those being measured with one of those lil hexagon shaped jobbies Haven't tried them on paper to see if there is even a difference in accuracy or not, but hey, they were cheap at the time!!!!!! lol

 

[jefats]

SD

Ogives are rarely in the same place bullet to bullet. Some of the better target bullets are close but you will find differences in them also. Using a hexagon comparator is a good way to sort them before loading and then you will only have to adjust your seating die to get the proper setting.

Can make a big difference accuracywise.

 

[Forum Boss]

Not uncommon to see .007-.010 move in length to lands on almost any barrel after 50-100 rounds. .030 is kind of a lot, but this can be from smoothing out of a small burr or ridge on lands. I had a Savage factory barrel that had a pretty big burr. When that ironed out, bullet L-to-Lands moved .050 and then stabilized.

 

[SDWhirlwind]

Thanks so much to everyone for their time and sharing information they have acquired over the years from their experiences.

Think I might have shot 3-4 five shot groups on paper with it after finding my load but can't remember for sure? Will try and get out this week and see what is does on paper for giggles.

Looking through my load data I see when new I was seating them .010 into the lands for some reason. Five years have gone by since I chambered it etc and with my memory beginning to suck I am a bit puzzled by why I seated them that way???

For the last 900ish I have loaded them to 2.180 OAL as I had measured 2.170 to lands. So I loaded these to 2.210. Shot a few yesterday at some real wild dogs and see I had one primer blowby. However the RP cases have 10 loads on them so not real surprising. Not seeing anything for sticky bolt or severely flattened primers. A few groups and the Oehler 35P should tell me more instead of asking unintelligent questions on the net!!!!!! I don't recall ever asking a how to or why question on the net the last 10yrs as for reloading. Always figured it better and a bit more intelligent to do my own testing with MY rifle to get appropriate and safe intell. So my lack acquiring reloading info second hand is some of the reason for my not knowing exactly how to ask or to explain if that makes any sense. One would think after over 80K of rounds under his belt and wearing out a Rock Chucker I would know more huh??? LOL

This is my first 6BR and only about the 3rd cut rifled barrel I have shot. Most are/were factory and majority used or Douglas and Shilen over the years. Others are for yotes etc so round count isn't to where I need to wonder or what if etc.
Thanks again everyone for sharing!