Can adding an scope cause your ammo to "key hole"?

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Zeeman99	Can adding an scope cause your ammo to "key hole"?	Lead	[-]
Posts: 1 (12/23/07 12:38 AM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Tags : None I have an M24/47. I removed the rear sight and put on a long eye relief scope on (no drilling, tap, etc.). The round was ripping thru the paper at the range and the range safety guy told me it was "key holing". I sent the rifle to Century Arms and they told me that I had voided the warranty (adding scope) and the scope was the cause of the problem. By the way Century Arms is the ---- so avoid at all costs. Anyway, does these seem possible? I am not a gun expert but it sounds funny to me. Also, where can I get a decent barrel and how much should I pay? Thanks. Last Edited By: nothernug 12/23/07 03:32 AM. Edited 1 time.
Mr Pale Horse		#1	[-]
Posts: 116 (12/23/07 12:57 AM) active member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	No, the modification you describe has nothing at all to do with the rifles ability to stabilize a given bullet weight and style. What kind of groups was it shooting before? If the bore is otherwise good, a proper crowning may solve your problem. I have had to return to CIA a P14 before, but was able to convince them of their willingness to remit a fund. Reiche kommen und Reiche gehen; alles das, der überlebt, sind MAUSER Gewehre.
Zeeman99		#2	[-]
Posts: 2 (12/23/07 01:10 AM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Maybe 12" groups. I could never get a consistent grouping. The bore looks good to me. It is clean and I can see rifling down the bore. What do you me by crowning?
Mr Pale Horse		#3	[-]
Posts: 117 (12/23/07 01:48 AM) active member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	At the muzzle, the cut edge of each rifling land and groove exit must be uniform and perpendicular to the line of bore. Crowning refers to the process of true-ing this critical area of the muzzle. Here Steve Wagner uses a ball grinder and bolt head to chamfer the muzzle, but it there are other (better) tools (pictured) and methods. DO NOT try this at home. The link is meant to illustrate and answer to your question, rather than to provide a how to. Find a good gunsmith, at least for an opinion, before giving up. http://www272.pair.com/stevewag/muzzle/mz.html You may also want to try some different ammo, and do some close inspection of the muzzle end of the bore, given the rest of the bore looks good. I had a 95 chilean 7x57 that was minty but had a burr at the muzzle likely cleaning rod damaged. Once that was fixed using a chamfer bit, it shot under 1" and is still going strong 20 years and hundreds of rounds later. Reiche kommen und Reiche gehen; alles das, der überlebt, sind MAUSER Gewehre. Last Edited By: Mr Pale Horse 12/23/07 01:56 AM. Edited 1 times.
nothernug		#4	[-]
Posts: 10502 (12/23/07 03:40 AM) Forum Site Moderator Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Howdy Zeeman and welcome to the forum! You been given some good advice that should start you on the way to some groups. But let me ask you to review or site rules please. We have a strict prohibition against profanity. That's why I edited you post. About Century. I'm neither for 'em or agin 'em. But if you drilled and tapped the receiver to scope it, I would have to agree that the warranty was voided and that they're within their rights. But I also agree that that should have had no affect on the accuracy Diplomacy is the art of saying nice doggie until you can find a rock. Will Rogers
gunslinger586		#5	[-]
Posts: 1831 (12/23/07 11:04 AM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Could be a few things in play here. What ammo were you using? What distance were you shooting at? What was the target made of? Sometimes, depending on the backing used, paper target holes can look "keyholed". With a no drill no tap scope mount, or any scope mount, it wouldn't change the barrel to bullet relationship. Try different ammo in a side by side comparison and see if there is any change. Can you post pics? If so, post one of the muzzle so we can see what you have. If it is a crown issue then a new barrel is not needed. Check out the crown repair techniques already described above and let us know how it turns out.
Zeeman99	Thanks for the help. Here are pics that may help.	#6	[-]
Posts: 3 (12/23/07 12:19 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post
metzgeri		#7	[-]
Posts: 41 (12/23/07 01:27 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Looks like your muzzle (the last 1/4" or so of barrel) is pretty well worn. A loose muzzle will definitely cause key-holing. Recrowning won't help this any. Drop a bullet down the muzzle. Does it swallow the bullet? Pics would be helpful here. metzgeri
SNEAKY PETE		#8	[-]
Posts: 43 (01/09/08 09:14 PM) active member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Old Sneaky here: I seem to agree that it appears that the rifling at the muzzle end isn't in the best condition and that situation does lead to unstable projectile flight(from a slight wobble all the way to total tumbling). I brought back from THE NAM a really beat-up K-98 with a terrible muzzle end and the instability resulted in silhouette patterns at 50 yards. As you seen to have a respectable scope on the rifle and using that you really don't need that front site. So what you MIGHT do is take the rifle to a competent Mauser-knowlageable gunsmith and talk to him about cutting back the barrel till the lands and groves are good, re-crown the barrel at that point(unless you choose to keep the rifle in origional-{collectable} condition and if so you then will have to live with the 12" groups.--your choice. THANX--SNEAKY
beanstrung		#9	[-]
Posts: 4048 (01/10/08 07:37 AM) Forum Site Moderator Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Counter-boring the muzzle is an option that would keep the appearance of the rifle original. I think I'd look at counter-boring rather than hacking it by cutting the barrel. --------------------------------------------------------------------------- What part of "shall not be infringed" don't you understand? Joel 3:9-10
Caffeinedog	Scope/mount combo?	#10	[-]
Posts: 6 (02/05/08 02:24 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Who is the mfg. for that scope mount? What type of scope do you have? I am thinking of adding both to mine. Thanks in advance.
cosmo05		#11	[-]
Posts: 142 (03/11/08 07:46 AM) active member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	Mr Pale Horse wrote: At the muzzle, the cut edge of each rifling land and groove exit must be uniform and perpendicular to the line of bore. Crowning refers to the process of true-ing this critical area of the muzzle. Here Steve Wagner uses a ball grinder and bolt head to chamfer the muzzle, but it there are other (better) tools (pictured) and methods. DO NOT try this at home. The link is meant to illustrate and answer to your question, rather than to provide a how to. Find a good gunsmith, at least for an opinion, before giving up. http://www272.pair.com/stevewag/muzzle/mz.html What do you mean do not try at home? I have used this method on a few 8mm and LE's to correct the same problem. Depending on how beat up the crown and end of barrel rifling is it will work, you need to be careful doing the work; but it is not brain surgery. I would rather attempt this than counter boring. Counter boring is needed if the rifling is wiped out in the last inch or so of the barrel.
Stonefly70809		#12	[-]
Posts: 437 (03/11/08 11:39 PM) Veteran member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts Report Post	I had a smith counter bore an M48 i had and it went from 12 groups to 3-4 groups. Freedom is not free. The price is very high and it never goes on sale.