Target crowns

[Whitetail Hunter]

What is it /ubbthreads/images/graemlins/confused.gif Does it have and impact on accuracy? I have a remmie 700 sendro in a 308. Right now my best groups are about 1 1/4 @ 100yds with 44.5 of Varget Win brass and primers with 165 SST and Balistic tips. OAL is 2.8.

 

[goodgrouper]

Target crowns come in various designs but are nothing more than a way to end the barrel at the muzzle. Their purpose is to protect the riflings and release the bullet evenly. The most common crown you hear about is the 11 degree crown. It was thought to be the most accurate at one point but it has pretty much been proven any crown is accurate as long as it is cut straight and true. Most bench rest crowns nowdays are being cut flat, straight across. THis doesn't protect the riflings as much as a countersunk crown, but for BR, you aren't going to be packing the rifle through the woods so there's really nothing to damage it. /ubbthreads/images/graemlins/wink.gif

I personally like a countersunk crown for hunting rifles, but if you have a muzzle break you are in little or no danger of getting to the riflings.

 

[D.S.]

Having a good riflesmith cut a new "target crown" on your barrel will probably improve your rifles accuracy-mabye even quite a bit. If there are any tooling marks left on your barrel's crown(its common w/ factory barrels), your rifle's accuracy will almost always suffer. Its also a quick and inexpensive procedure so if it doesn't help, you havent wasted much $. I may be wrong but I think the gunsmith I use charges $70. Good Luck, Drew Stuart

 

[Whitetail Hunter]

Goodgrouper

So the crown protects the rifling and makes the end of the barrel perpendicular to the rifling. I assume that this makes the gases exit the barrel evenly, thus not disrupting the flight of the bullet.

 

[Whitetail Hunter]

D.S.
The end of my barrel does have tool marks where it was turned. When I shoot 5 shot groups I consistently get 3 in a bug hole and 2 are out, but as you said it isn't that much $ to spend

 

[Michael Eichele]

If a recrown doesnt help, maybee try 168 and 175 SMK, 178 AMAX, RL-15 or 4064IMR along with federal gold medal match primers and lapua brass. Also 1 thing that might make a huge differance is 2.825-2.830" OACL depending on what your magazine will allow. 2.825 will work for sure and some BDL's will allow 2.830".

 

[Whitetail Hunter]

meichele
I haven't tried any different lengths yet. I am waiting for my Sinclair bullet comparator so I can sort my loads to the same length to elimate another variable.

 

[goodgrouper]

THat is correct.

 

[4ked Horn]

While we are on the subject... I thought I saw in a past issue of Varmint Hunters that Gordy Gritters makes what I think is called a "Double crankshafted" crown. I might have that name totaly wrong, but the picture (which I cant find to save my life) appeared to be a very counter bored flat or 11 deg crown. Almost like a 1/4" or 3/8" deep cup.

Do you have any idea what I'm talking about? Did I see that right or am I all wet? If there is such a thing what purpose does it serve? Wouldnt the escaping gasses outrun the bullet and create a very turbulent area in front of the muzzle?

 

[Centre Punch]

4ked,
Although i have not seen the picture, from your description it sounds just like what i used to cut on the muzzels of 1911 bull barrels.
I called this a recessed target crown.

Ian.

"I meant to shoot the pike but the duck got in the way"

 

[BountyHunter]

That is nothing more than what used to be called a stepped crown. Gordy builds some very good guns and is an excellant 1k smith.

BH

 

[4ked Horn]

I have seen stepped crowns that were shallow. Less than 1/8". This one seemed abnormally deep and that is why I am wondering if it would affect the accuracy. But when we throw the name Gordy Gritters in there I can't help but think that there is some hidden benefit that would increase the accuracy or at least negate the effects of the turbulent balloon cloud being diverted forward around the bullet. The design and the designer don't seem to match.

Did I have the name right? I know he didn't use the words "stepped crown" which is what caught my attention.

 

[Ahab]

My Savage 111F in 7X57 wouldn't group better than 1 1/2"@ 100yrds after bedding and trigger work. My smith told me the last half inch of the barrel was very rough and recommended it be cut back and step crowned for $75. I told him go ahead. It now groups an easy 1/2". /ubbthreads/images/graemlins/smirk.gif

 

[Whitetail Hunter]

Thanks to all. I understand a little more on crowns and what they do or don't