Reply With QuoteI don't know why he would tell you that.
I had my factory barrel (6.5 Creedmoor) replaced with a Shilen Select Match grade in 6.5 Creedmoor.
The gunsmith set the head space a little sung. That’s what he told me he was going to do.
I don’t reload at the moment but reloading is something I plan on doing. The factory rounds
cycle through the magazine and the bolt closes with no problems but he told me to take a marker and color the ogive to make sure the bullet does not touch the rifling.
I did that and could not see any marking on the ogive. I took a new round placed it in the chamber and closed the bolt and this is the results. Small markings from the marker on the bullets ogive.
Should I be concerned with this? I’ll try to post a picture.
I don't know why he would tell you that.
Loading for my 223AI, I seat my 75 grain Hornady BTHP's .008" into the lands. Of course, I adjust powder charges to allow for this. Factory rounds just touching the lands should give you no problems.
all of the above.
I don't think it's a problem, unless the bullet is pushed too deep into the rifling. Just touching, or even .05 inches into the rifling is not a problem. Normally, if the bolt is not difficult to close, and you are not getting high pressure signs, it's okay. (If the bullet is initially "crammed" into the lands before ignition, it can cause high pressure spikes when fired.) But, many hand loaders purposely seat their bullets slightly into the lands. If factory bullets are into the lands, it's a sign the throat is cut a little short, it should maybe be cut deeper. Sometimes, if the throat is too shallow, when you first chamber a round, the lands will push the bullet deeper into the case. When you remove it without firing it, the overall length of the cartridge will be less than a new cartridge. To confirm whether that is happening, take a new, fresh cartridge, close the bolt on it. remove it and then compare it to another cartridge. Should be the same.
Thanks,
I really appreciate the help. foxx I will take your advice and chamber around then compare
it to a new one.
I am confused did the smith use a go no go gauge or did he use some old brass to set the head space please ask him
The smith used my go no go gauges. I just ordered A bullet comparator and insert so I can check the ogive after I chamber a round and compare it to a new factory round.
can shilen provide you with the chamber specs? that might save you some time,Originally Posted by Royce 618
newbie from gr, mi.
I have sent shilen an email waiting for a response.
I'm still confused on the headspace thing. I've never seen a factory round anywhere close to the lands. You would be crushing the shoulder waaaay before you hit the lands with a factory load
I was concerned about the headspace being set a little snug but when I load a factory round
I get no resistance when I close the bolt. The smith said the chamber specs were different on a custom barrel vs factory barrels and to
color the ogive with a marker then check for a ring on the ogive. Maybe I'm reading to much into too this.
Head spacing is not issue I am taking about, but the length of the throat. The throat is the portion of the chamber that the bullet itself is inserted into. If the bullet is seated too long for the throat, or, conversely, the throat is not cut deep enough for the bullet, the bullet will be "stuffed" into the barrel where the rifling stars. Doing so causes a spike in initial pressure as the powder burns because there is too much initial resistance to the bullet exiting the case before "getting up to speed". It is often described as being similar to trying to drive your car over a curb without a running start... start with your tire against the curb and you really have to "gun it" to hop the curb. The depth of the throat determines this, not the head space.
Doesn't mean there is a problem here, that's just what the smith and I are referring to.
Maybe im just missing something here. Headspace is either right or wrong, we're talking just a few thousandths of an inch difference between right and wrong, and I understand what the throat is. I guess I've just never seen a throat cut so short that a factory round would hit the lands or maybe I've just never really paid that much attn to it. I couldn't imagine shilen cutting a throat that short unless you specifically asked for it and if that was the case, you would already know the chamber specs. I'm just wondering if the smith is just being cautious or he already knows it has a very short throat
Some of the factory savage barrels have had issues with short throats.
I set my headspace short and new brass is snug.
OP, if you've got easy bolt closing and no pressure issues I'd say your GTG.
I have a Shilen in 260 and it's been an excellent barrel.
Please post your ogive results when you get them.
Just received my SAAMI specs.
Says Bolt Face to Throat 2.340
Headspace Min. 1.541 Max 1.551
a view of the inside
http://imgur.com/a/4fPsV
especially this one:
newbie from gr, mi.
That's kinda cool. can you make multiple copies of this (of course you can) and, on each, label everything with pointers, etc. s.a. headspace measured from here to here... throat... bearing surface of this particular bullet... draw-in exaggerated dimensions of what a "tight" chamber would be versus a "loose" chamber... Just a thought b/c when I first got into hand loading I did not understand all these terms and these types of PHOTOS with explanation would have help speed up the learning curve of different concepts to consider when solving problems, discussing merits of different styles of barrel design, etc.
I would do the same. When you don't know someones reloading experience or skill level it's best to be conservative. Therefore if they were to load to max and the bullet was into the lands there might be some real "ignition excitement!" that could end up being, believe it or not, the gunsmiths fault.
I understand the pressure spikes and all that, just thought he was speaking of factory rounds because he said he doesn't reload.
Guess I just wasn't seeing the big picture and been reloading since I was a kid and take things for granted.
great photos , gives a clear view how the ogive contacts the lands and case neck length in chamber.
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