7PRC Partition wont chamber

[V00D00]

Take a fired round and pop the primer. Try a few different fire rounds until you find one where the bullet slides in and out of the neck with just a little resistance. You can pinch the neck with your fingers to make it oblong to increase a little bit of pressure.

Seat the bullet long then softly close the bolt. It will seat the bullet to the lands. Repeat 10 times until you get a consistent CBTO. That will give you an idea of your distance to the lands.

ill do this this evening. do i need to strip the bolt in order to do so?

 

[mtnbound]

and this is what im trying to figure out. is the problem me, or the throat

I would build a test cartridge at 3.320 or 3.340 if you ever want to run heavier bullets and give it to your smith and have him redo the chamber.

 

[V00D00]

I would build a test cartridge at 3.320 or 3.340 if you ever want to run heavier bullets and give it to your smith and have him redo the chamber.

this is where i was at this morning. called the smith to let em know im sending it back and he says no problem. but..before you do. lets try one thing. i obliged. he is suspecting a carbon ring. said he has seen them on 7prc less than 10 rounds. so ill try that this evening. i have a 22 round count. not much but it would explain a few things. and ill do anything he ask to try to get to the bottom of this. i still suspect a bur, or a short throat or something that is causing something funky to go on.

 

[WeiserBucks]

If anything develops enough of a carbon ring in 10 rounds to cause problems it needs to be thrown off a cliff ASAP.

 

[Judd]

I'd bet money it's a saami chamber. My hunch is you're not pushing hard enough on the shaft of the Hornady tool. Which by the way, isn't a super accurate way to measure base to lands but it will get you in the neighborhood. How can I prove that, you might ask? Give that tool to 3 different people and you'll get 3 different final answers. They might be close but they won't be the same.

By all means, do what your smith has said because he's not been wrong yet. But what I'd do to prove the whole carbon ring...chamber one of your factory loads and see if there are scratches on the bearing surface or land marks on the bullet. If there is nothing...push harder on your Hornady tool. If it's a carbon ring you'll have scratches on the bullet bearing surface and it will be hard to chamber.

You should, at least initially, be pushing hard enough on that bullet in the Hornady tool that you're pushing the bullet into the lands and when you pull the tool out, the bullet is stuck in the barrel. Use a cleaning rod to gently push the bullet back into the action. Closely paying attention not to nick the crown or bang up the inside of the barrel with the rod. Bore Tech makes a great bullet pusher jag to go in a rod.

 

[Str8shtr]

Usually when you're bullets seated too long it sticks in the lands. After not chambering is it wanting to stay in the chamber or does it just come right out?

 

[wapitibob]

Smoke the bullet in a wax candle flame, then use the comparitor. You'll see exactly where it's touching.

 

[V00D00]

I'd bet money it's a saami chamber. My hunch is you're not pushing hard enough on the shaft of the Hornady tool. Which by the way, isn't a super accurate way to measure base to lands but it will get you in the neighborhood. How can I prove that, you might ask? Give that tool to 3 different people and you'll get 3 different final answers. They might be close but they won't be the same.

By all means, do what your smith has said because he's not been wrong yet. But what I'd do to prove the whole carbon ring...chamber one of your factory loads and see if there are scratches on the bearing surface or land marks on the bullet. If there is nothing...push harder on your Hornady tool. If it's a carbon ring you'll have scratches on the bullet bearing surface and it will be hard to chamber.

You should, at least initially, be pushing hard enough on that bullet in the Hornady tool that you're pushing the bullet into the lands and when you pull the tool out, the bullet is stuck in the barrel. Use a cleaning rod to gently push the bullet back into the action. Closely paying attention not to nick the crown or bang up the inside of the barrel with the rod. Bore Tech makes a great bullet pusher jag to go in a rod.

i mean you may be right. im probably not pushing as much as i possibly can but i thought u werent supposed to. im pushing firmly until i feel resistance. when i pull the case out the bullet stays. hell sometimes i even back the lil rod out a lil bit when it stops and give it a lil tap lol. with that being said im not pushing the bullet down the barrel, no.

 

[V00D00]

Usually when you're bullets seated too long it sticks in the lands. After not chambering is it wanting to stay in the chamber or does it just come right out?

if i load a bullet at book length i cant chamber. cant close the bolt. most the time the bolt handle isnt even lined up with the cutout on the stock for the handle. it stops way before the bolt can think about rotating. then i pull the bolt back and knock the bullet out the barrrel with the case.

 

[Str8shtr]

if i load a bullet at book length i cant chamber. cant close the bolt. most the time the bolt handle isnt even lined up with the cutout on the stock for the handle. it stops way before the bolt can think about rotating. then i pull the bolt back and knock the bullet out the barrrel with the case.

So the case comes out but the bullets stays in?

 

[V00D00]

So the case comes out but the bullets stays in?

no the bullet and the case are still together. but i do have to knock it out with a rod.

 

[Str8shtr]

no the bullet and the case are still together. but i do have to knock it out with a rod.

How are you removing the bolt? once the extractor goes over the case rim it is pretty difficult to get the bolt back without the case coming out.

 

[V00D00]

How are you removing the bolt? once the extractor goes over the case rim it is pretty difficult to get the bolt back without the case coming out.

when i was trying to load partitions at saami spec the case didnt go far enough into the chamber for the extractor to grab the case yet. wasnt nothing to pull the bolt back. the ogive was hitting the lands stopping the round from chambering. since then i have moved away from partitions to eldx and ablr because i have to seat the partition so far into the case its pointless.

 

[Str8shtr]

when i was trying to load partitions at saami spec the case didnt go far enough into the chamber for the extractor to grab the case yet. wasnt nothing to pull the bolt back. the ogive was hitting the lands stopping the round from chambering. since then i have moved away from partitions to eldx and ablr because i have to seat the partition so far into the case its pointless.

seems like the extractor should grab even if not chambering all the way. Maybe your extractor is binding up and not sliding over the case rim.

 

[Str8shtr]

Do you have the tools to remove the barrel?

 

[goosedog]

Have you pulled the ejector out? If you want any feel when chambering a round to feel shoulder bump or the bullet touching the lands having the ejector out really helps then you can seat the case on the bolt face and the extractor will hold it in place

 

[Q_Sertorius]

Almost a hundred posts in and I am wondering why the OP didn’t just buy a case of that ammo that shoots MOA groups and stop worrying.

 

[Walker6]

if i load a bullet at book length i cant chamber. cant close the bolt. most the time the bolt handle isnt even lined up with the cutout on the stock for the handle. it stops way before the bolt can think about rotating. then i pull the bolt back and knock the bullet out the barrrel with the case.

Why are you worried about book COAL? The book doesn’t know what reamer your smith used. What matters are your magazine confines, the bullet you want to shoot, and the CBTO measurement in your rifle.

Get a sharpie and color from the case wall/shoulder junction to the tip of the bullet. Chamber this dummy round at different seating depths and see where it rubs the sharpie off. Ogive? Shoulder? Neck? A gouge in the tip or case wall? Use your Sinclair Comparator (subtracting 1”) and write stuff down.

And post some pics..

 

[Str8shtr]

Look at the SAAMI reamer print from PT&G or Manson and you should be able to roughly calculate how far out you should be able to seet a bullet.

Your extractor should be grabbing the case even if the round doesn't chamber so I'd figure that out first.

 

[V00D00]

UPDATE yesterday evening i got home, sorted through some of these comments. Judd's comments stuck out to me the most about not measuring the lands correctly. thought to myself ima show him. jammed the case into the chamber as far as it would go. pushed the bullet into the lands as hard as i could, several times. getting ogive measurments around 2.427, 2.434 etc. loaded a eldx at book length 3.320 and thought to myself ima jam this mfer in there so hard it gonna chamber. and if shit gets fkd up ima let the smith deal with it. round chambered flawlessly. smooth as butter. Didnt even fight me. Didnt use force. And immediately i thought that wasnt supposed to happen. went look back into my notes to be certain i did indeed try to chamber the eldx and ablr at book length when the projectiles came in as all of this has turned into some weird blur over a period of i dunno, 2 weeks maybe. i certainly have. right there in black and white. So then I loaded an ablr at 3.320- again chambered flawlessly. put the oal guage back in the chamber and getting 2.6 numbers now instead of 2.4 numbers. took a fired case, put loctite in the neck, chambered it. 3.342 coal 2.641 cbto said aint no way. loaded 3 bullets 3.320 put em in the mag as i havent used the mag yet to this point, cycled flawlessly. took one colored the bullet with a sharpie, put it in a fired case and left long- just marks at the ogive. i dont know where the problem was, or what the problem was. all i know is the problem seems to be gone. and i aint complaining. I ordered a borescope so that i can see if maybe theres a piece of bur or something that is no longer touching anything. maybe it broke from all the banging the buttstock on the ground to get the bullet out of the lands all these times. i dont know. i didnt put clr down the barrel yet as the smith suggested so doubt it was a carbon ring issue.