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View Full Version : New 6.5cm LRP, Odd Crown Bur



Ninedv
04-17-2012, 09:24 AM
My LRP showed in 6.5 Creedmoor. Enjoying this cartridge so far but havent gotten the chance to stretch the barrel yet as i was working on load development. I noticed an odd bur on the crown and it is enough to catch a finger nail and fibers from cleaning patches. I tried to take photos but that one is tough. Would this be something to worry about and what would be the fix? The rifle (and me) are grouping in the 1" to 3/4" 5 shot groups at 100 as of now. My other savages dont have this bur and all easily group 1/2" most better. Should i worry about the bur and keep testing ($) or get it looked at and hope to save the coin in the long run?
Bur shows as the shiny spot in both pictures about 12 o clock.
Jesse

http://img.photobucket.com/albums/v288/ninedv/IMAG0574.jpg

http://img.photobucket.com/albums/v288/ninedv/IMAG0575.jpg

teebirdhyzer
04-17-2012, 01:11 PM
your going to get a bunch of different answers on whether this is going to affect accuracy or not. There is quite a debate about the crown and how it makes a gun shoot. you could possibly take a case mouth chamfer tool and nock that down, but I would probably get a smith to either smooth it off, or recrown it.

Ray Gunter
04-17-2012, 01:52 PM
... I would probably get a smith to either smooth it off, or recrown it.


+1

If you leave it you'll always have a thought that ..... that burr caused another flyer

savy22br
04-17-2012, 04:39 PM
Just get it recrowned crowns the last place the bullet touches and the most critical part of accuracy if you ask me!

ellobo
04-17-2012, 04:46 PM
If you see a streak of powder residue emminating outward from that burr, then you have a problem. I dont see one but you may have wiped it away. If gas is leaking past that burr it will only get worse. Have a gunsmith recrown it and get rid of the worries.

El Lobo

243LPR
04-17-2012, 05:17 PM
Check Brownells for a crown lapping kit,I think thats what its called.All you need is that and a drill.

frank1947
04-17-2012, 07:20 PM
is it brand new , if so send it back to savage, I agrre with a bunch that is the last place the bullets leaves i feel it is critical to accuracy

Ninedv
04-17-2012, 08:04 PM
Yes. brand new out of the box rifle... i have lapping compound from a scope mounting kit... thinking about going the brass screw route with it as sending it back seems to be a long way around what could be a simple fix. Thoughts?

savy22br
04-17-2012, 08:12 PM
Lets not talk about it get it done its your choice and a fairly simple one at that! If it dont shoot after your done brass screwing the barrel warranty id void send it back. Or cut your losses and call jim briggs!!!

1jonzmith
04-18-2012, 11:25 AM
Think of it this way: At the instant the bullet leaves the muz the gasses explode from around the base of the bullet. If the crown is even then all the forces will be even and the net affect on the bullet will be nil. With a burr, the forces cannot be equal so in effect the end of the bullet gets "slapped" as it exits the barrel. You wobble right after you get slapped, right? And after that you settle down on a "new" direction and the direction will probably be different each time you get whacked. Same with bullets. ??? ;D

Trent
04-18-2012, 06:36 PM
I think we'd need a much better photo of the crown before we can make an informed call. I can't see anything in the photo provided.

Corprin
04-18-2012, 09:11 PM
My LRP showed in 6.5 Creedmoor.


On a side note, did you happen to order the rifle from Jim on/around April 6th?

Ninedv
04-19-2012, 09:11 AM
Yes the rifle came from NSS. Jim was wonderful to deal with. Did i buy his last one out from under you? I will try to get a better picture of the crown when i find a better camera. Think i will try the brass screw head trick and if that doesnt work its off to the smiths.

frank1947
04-19-2012, 11:01 AM
be careful, you know i have the same gun in a 260rem until i put a couple 100 rounds down it and found the right load it did about the same grouping as yours.

Corprin
04-19-2012, 12:31 PM
Yes the rifle came from NSS. Jim was wonderful to deal with. Did i buy his last one out from under you? I will try to get a better picture of the crown when i find a better camera. Think i will try the brass screw head trick and if that doesnt work its off to the smiths.


Nope, I got one in .260 that day.

I am wondering if you were the customer that called earlier in the day with the choice of either the 6.5cm or the .260rem... eventually choosing the 6.5cm because of a "guy/friend looking to buy the .260" that Jim had in stock?

IF that was you, I would like to personally thank you for choosing the 6.5cm, as I know the choice was partially made by you being a nice guy! Both my friend and I picked up the .260s later that afternoon, and I drove home with the rifle I wanted!

Harriershot
04-19-2012, 01:26 PM
Putting a pro finish on the crown is very easy. I bought the brass dowel tool from Brownells. Put the but of the rifle on the ground, hold the barrel just under the muzzle while using the drill/ brass dowell crown tool in your right hand. I use lapping compound spread on the crown and dowell, I run the drill at a low sped and with no more pressure than the weight of the drill I let the brass dowel find it's center while rotating my drill holding hand to the left and to the right so as not to hold it in any one position for very long.
It does not take but a minute or two of this to cut a uniform fresh crown. I have done to all my rifles and the crown looks real clean and uniform.

Good lock

Charlie

Ninedv
04-19-2012, 07:59 PM
I can not confirm or deny that i was the guy looking for that last 260. I had my name on a 6.5 till i got my FFL in line. I am glad you and friend got what you needed though. What groups have you been getting from your new rigs? I will be doing the brass screw and lapping compound after i finish dinner. =)

Corprin
04-19-2012, 08:37 PM
Well, IF it was you... thank you!

As for groups, mine is currently shooting MOS (minute of sitting in the safe) :( I have a couple big projects due at school this week, and finals will be plunking down right after that. Won't be till mid May before I can get on the firing line.

Texasshooter36
04-19-2012, 10:23 PM
Get a gunsmith to recrown it if you are worried about it most manufactures dont put a real crown on them!

1jonzmith
04-25-2012, 02:58 AM
If I were doing it myself I would probably go the drill with the brass screw route. Except I played that for my Smith and he got animated with.... No, John! No drill. Do it by hand. Check your work with a loupe. He gave me a steel ball bearing and suggested that that would work better than brass. I think brass would imbed the grinding compound and do the job quicker.

Stuff some oil soaked patches in the muz before laping. Push then down the bore a half inch. When you are finished lapping then push the oil patch out of the muz from the breach. Push a few wet patches thru from the breach and wipe the compound off of the crown with every cleaning patch. Unless, of course, you are trying to "fire lap" the last inch of the barrel. LOL I get anal when it comes to grinding compound around my barrel or ammo and I lap everything I can get to in any gun I own. :)

Have fun,


John