Ok simply I have a cm and am trying to use the 140gr matchkings my rifle wont extract unless I load the bullets to a col of 2.717 isthis to short or does the mk have to be seated this short? Help please
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6.5 creedmoor need help
- Thread starter Baseball328
- Start date
When you say wont extract, do you mean a loaded round or fired round?
If loaded they could be too long and you are jamming the bullet into the lands.
If fired, probably same issue and you are over pressuring.
No one can tell you how long to load for your rifle without knowing your chamber specs, or without you measuring the distance to the lands with that particular bullet.
If loaded they could be too long and you are jamming the bullet into the lands.
If fired, probably same issue and you are over pressuring.
No one can tell you how long to load for your rifle without knowing your chamber specs, or without you measuring the distance to the lands with that particular bullet.
2.717 with a 140 smk is very short considering the short bullet length and bearing surface of this bullet. If your chamber is indeed that short I would have it taken to a smith and checked cause that's an excessively short chamber. In my experience 2.800 area is the place to start and have a happy load with the creed.
ok hopefully this will help the brass is made from 308 hornady match trimmed to 1.900 i shot 10 rounds of hornady factory ammo through it so far i have been seating the bullets in the brass to try and find where the lands are i have no way of measuring for col besides trial and error but funny thing is thier are no skuff marks on the bullets even when loaded out to like 2.800 but the rounds will only chamber completely around the 2.720 area or below the brass is not fire formed i have never done this before with a caliber you have to fireform brass so im new to this maybe thats part of the problem i dont know but even if the bolt does not completely close i cant pull the shell back out i have to use a cleaning rod to tamp it back out
Dump that fire formed shit. Buy some hornady brass and go on. There's no way it's gonna chamber and be right until you fire form it so the shoulder comes into spec. You probably have a neck thickness issue I would say as well. When you size down you generally need to trim the necks to bring them into spec as well.
I agree, get some 65CM brass. The neck thickness of squished down 308 is making you seat the bullets so the ogive is probably behind the neck's leading edge.
Punctuation may keep us from getting seasick reading your posts too....
Punctuation may keep us from getting seasick reading your posts too....
Sorry not very good in the writing department. But i take it you realize this. I measured my neck thickness the hornady book says its susposed to be .294 and mine is .293-.295
Is that measured with the bullet seated in the case? If not then when you seat the bullet the thickness of the case is bigger and causing your issue.
This brass you are using, have you tried to chamber a piece of it without a bullet seated in it? Do you know the neck measurement of your chamber?
My Creedmoor surprised me at first too. I got it from the gunsmith and shot 20 rounds of factory ammo. It shot great, and I thought everything was ok, so I sent it off to be nitrided. When I got it back I had some handloads duplicating factory ammo ready, and they would not chamber. It turns out that my throat was short all along. The neck tension of factory ammo is loose enough that you can jam bullets. My handloads have more neck tension and wouldn't let me jam the bullets.
The throat on my Creedmoor is so short that the 140 A-max's have to be seated at 2.74", and the 130 Norma's are touching at 2.68". It's too late to change mine now that its been nitrided, but I suppose it's better to have a throat a bit too short than to have one that doesn't allow me to get near the lands without being to long to fit in the mag.
Your rifle probably has the same problem. Have you shot factory ammo with it yet?
The throat on my Creedmoor is so short that the 140 A-max's have to be seated at 2.74", and the 130 Norma's are touching at 2.68". It's too late to change mine now that its been nitrided, but I suppose it's better to have a throat a bit too short than to have one that doesn't allow me to get near the lands without being to long to fit in the mag.
Your rifle probably has the same problem. Have you shot factory ammo with it yet?
I disagree, actually STRONGLY disagree, with your statement. 142 SMK you'll be about 2.800" but with a 140 SMK you'll be significantly shorter. 142 SMK is something like 14 ogive and the 140 is more an 11 ogive, possibly even a 9 ogive. 2.72 w/140 SMK is about "normal" for standard 6.5 Creedmoor chamber/reamer as designed by Hornady.
Doesn't matter at this point. It's a neck thickness issue from his sizing 308 brass and not turning it. I am running 140 amax in my creed and 2.810 is .020 off the lands. That's what I was basing my thoughts off of and the 2.800 area is where most that I know that have a creed are running them.
not to mention if he is having a hard time closing the bolt on a 2.717 cartridge using the 140 I would still say that is a short chamber.
not to mention if he is having a hard time closing the bolt on a 2.717 cartridge using the 140 I would still say that is a short chamber.
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0.298 for loaded round neck diameter I'd want at least 0.301" in chamber which is more then I'd expect to see with a 6.5 Creedmoor standard reamer. Neck turn the brass or better yet, get some 6.5 Creedmoor headstamped brass/ammo.
Yes I understand that. I have a box of them setting here and I am looking at them again. I think he has the problem figured out either way tho. Thanks for the info.
Fresh GAP chambered 6.5 CM, 140 SMK touching lands is 2.730 and some change. 0.013" difference is in the noise.
I'd say neck thickness is a bigger issue at this point but sounds like a pretty standard 6.5 Creedmoor chamber to me in terms of freebore dimension.
I'd say neck thickness is a bigger issue at this point but sounds like a pretty standard 6.5 Creedmoor chamber to me in terms of freebore dimension.
