16 replies to this topic

[homemade]

well we had a guy bring a remy 700 in 22-250 into the shop today it wont shoot worth a dam and is key holeing now when it was shooting just over half inch before with nothing changed.same scope not loose apx 220 rounds through the gun its clean hes been reloading the same from the beginning lets see if we can guess what happened to cause this.just playing a guessing game its what we did at the shop at first until we figured it out.

[jeager]

Keyholing?1) If he is suddenly using longer, heavier bullets the present barrel may have an improper twist.2) Recrown the muzzle.

[OrneryOlMofo357]

Tried a new scope first?

[ShooterJohn]

It sounds like copper fouling to me, but you said it was clean correct?To bad we don't have the gun to look at like you guys did this would be easier.

[OrneryOlMofo357]

Maybe he tried using the Barrel as a jack handle and Bent it? lol

[KNOCKED UP]

Grant,Remind me not to shoot any of your guns.Tom

[bzzrd feedr]

Too hot of a load or bad batch of bullets?? Hard to believe it's the barrel because it's so new but it might have a damaged crown. The scope won't make a gun keyhole.

[ehd]

pressure point on the stock..

[Bisley]

It sounds like copper fouling to me, but you said it was clean correct?To bad we don't have the gun to look at like you guys did this would be easier.

Funny, because those were first two thoughts, but then I thought that copper fouling would explain the groups, but not the keyholing. It's kind of like asking what's wrong with my truck motor without being able to hear it run

[ShooterJohn]

Copper fouling can definitely be the biggest cause of keyholing especially in the faster calibers. Group size changes can be caused by just changing primers. But a bad batch of bullets can cause keyholing as can a dinged crown. If it shot the very same bullets with the same load previously I think there will be copper in the bore. The bullet diameter is correct I'm assuming and nothing has changed with the bore diameter? Like I mentioned above not having the gun to inspect it can be difficult to diagnose quickly.

[Jason]

It could be what was happening at a nearby local gun shop. Kid (young adult) purchased a AK variant and was having the same problem. Took it back to them to figure out why it was happening. Turned out he was firing 5.56 out of it. Amazingly the gun was was able to fire that round considering the size difference.

[Bisley]

Copper fouling can definitely be the biggest cause of keyholing especially in the faster calibers.

Goes to show you're never too old to learn. I have never seen one fouled bad enough to keyhole, nor did I know it could cause it to that degree. It must have to be R E A L L Y fouled to do that

[homemade]

well come to find out the locking bolts barely made contact at all so almost every shot he fired was increasing his head spacing.we checked and it was out of spec pretty good.pulled the barrel and was only contacting in 1 tiny spot when locked up.

[ShooterJohn]

Wow, never heard of that causing bullet tumbling. I'm surprised the bolt wasn't extremely difficult to open due to case expansion.

[Lang]

Depending on what gr wt bullet he was loading it could be under charge or over charge. I had something similar happen with a 30-06 I was trying to load 125 grain using 4064. I tried everything. The gun simply didn't like that lite of a bullet.

[ratassassin]

Interesting about the ever increasing head spacing. Was he getting blown case heads?

[homemade]

minimal signs on the case