McGowan chambers

[tomme boy]

Has anyone measured how straight the chambers are on a MG prefit?

[jonbearman]

Nope, but the three or four I own shoot real well. It would be interesting to measure one but with all the indicating it would be moot unless it shot like garbage. Why don't you ask DennisH on here as he works for mcgowen.

[foxx]

+1

They do good work.

I am curious, why do you ask? I have never heard of any respectable barrel maker having a problem with that.

[tomme boy]

Must not have looked at Shilen then.

[foxx]

What do you mean, Tomme? Shilen has good reputation, for sure. Have you seen them with crooked chambers? I am asking sincerely b/c I have never heard of such thing. That can't be good.

[tomme boy]

http://www.savageshooters.com/showthread.php?39633-Shilen-chamber-reamers

I did a cast of the chamber of one of their barrels in 308 win. While the chamber was actually straight, it was way f'ed up on the dimensions.

[jonbearman]

All barrel makers have a bad one once in awhile. Tomme did they replace it or what?

[Rooster 50]

I use a borescope a lot and can say for sure the chamber that is cut concentric to the bore is the exception rather than the rule.......for the avg commercial rifle manufacturer.

Can't speak for the custom guys but in any event it is the guy who cut the chamber not the barrel maker who screws it up.

[tomme boy]

NO, they said it was in spec. I shoot mainly cast lead bullets and the dimensions for lead are more critical than they are for shooting jacketed. It shoots jacketed really well. But that is not my cup of tea. I have designed a couple of moulds for shooting lead and the chambers have to be a certain way and in spec to shoot up to potential.

This one has a too fast twist and I wanted to go to a slower twist to shoot the cast bullets more accurately within a certain RPM for the bullet. Lead has a problem with RPM that going over will give you major accuracy problems. 120K-140K RPM is usually in the range that most accurate load will be found. Velocity will be dependent upon twist. If you want more speed then you will have to slow the twist down.

[tomme boy]

And this WAS chambered by Shilen.

[Rooster 50]

So are you saying that the twist rate is too fast or that the chamber is not concentric to the bore. Also WHO cut the chamber. If it was Shilen you might have a case but apparently they think it's within spec whatever that means.

[tomme boy]

According to their print # they sent me, It is supposed to have a parallel free bore. This has a straight free bore. The neck is really long and the neck is wayyy over sized from what it should be.

If you read, I never said that the chamber on this barrel was not straight. I asked if the McGowan chambers are straight. I know that their quality seems to go up and down all the time and it seems to be the luck of the draw when you order one. I had a 223 that the barrel looked like it was a factory Remington being that it had chatter marks in the last 1" of the barrel. I sent it back and they cut off the bad section for me and re crowned it. It shot great.

If someone here has ever made a cast of their chamber, I would like to know. It would speak volumes on how close they are.

[tomme boy]

Roster, read what I posted. Shilen cut the chamber. Yes the twist is too fast for what I want to do right now. At the time, I wanted to shoot slower. Now I want to shoot faster. That is the reason for a new barrel.

[Rooster 50]

I did read what you posted first you ask about MG chambers and then you insinuate the Shillen cuts theirs wrong. Sounds to me like you have the wrong twist barrel and are trying to find an excuse

[tomme boy]

Learn to read would you?????

Read the other thread I posted and maybe you will get a clue as to why I want to get a new barrel. Look at the pics and the measurements I posted.

[Rooster 50]

Geez man you keep changing the rules. I can't keep up.