22 Creedmoor issue

[haisardao]

Hi all, question for the group, I recently put together a 22 Creedmoor on an Origin action and a PBB prefit barrel. Headspace checked multiple times and on point. Now the problem. I'm loading 77 TMK on Alpha brass over H4350, 41.7 gr. never got pressure on my ladder. Extraction is hard, no bolt lift, and case grew .001 regardless of the load. What bothers me is this hard pull to get extract, and almost a clicker.
Any input is appreciated, what do you think it's going on.
Thansk

 

[Justice1327]

What does the sides of the case look like? Scratches?
which reamer was used? I believe they have a Sammi Reamer, which is no neck turn and then they have a neck turn reamer.
I am not surprised that the case overall length did not grow that much. May take several firing for that to happen.

 

[haisardao]

I don't see any scratches but I'll recheck, rounds chamber fine so I'm guessing no neck turn, free bore is .120 1:8.

 

[orkan]

Hi all, question for the group, I recently put together a 22 Creedmoor on an Origin action and a PBB prefit barrel. Headspace checked multiple times and on point. Now the problem. I'm loading 77 TMK on Alpha brass over H4350, 41.7 gr. never got pressure on my ladder. Extraction is hard, no bolt lift, and case grew .001 regardless of the load. What bothers me is this hard pull to get extract, and almost a clicker.
Any input is appreciated, what do you think it's going on.
Thansk

Can I see a high res picture of the base of one of your fired cases?

Can I see another picture of your action, top down, port side, bolt lifted, but with the bolt down enough so that it starts to get the cocking piece to engage the sear?

Like this:

-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

 

[Dmagna]

What's the speed?

 

[haisardao]

Can I see a high res picture of the base of one of your fired cases?


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

Yes Sir, as soon as I get home.

Velocity

 

[orkan]

If you haven't pushed at minimum 150rnds through it yet... then 41.7 is going to be a pretty hot load. Even alpha brass won't take most folks starting there on a new barrel. 40.5 would be a MUCH better place to be until things loosen up a bit.

I know, it's no fun. I hate having to do it on all my new rifles too... but it's just much better in the long run to let them breath a bit before stomping on them. No matter what you might have heard/read... 41.7 is a STOUT load behind a 77gr.

For your edification, sharing velocities without barrel length does no one any good.

By the way, if you have the capability, video of that portion of your action through the bolt lift cycle would be even better.


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

 

[haisardao]

If you haven't pushed at minimum 150rnds through it yet... then 41.7 is going to be a pretty hot load. Even alpha brass won't take most folks starting there on a new barrel. 40.5 would be a MUCH better place to be until things loosen up a bit.

I know, it's no fun. I hate having to do it on all my new rifles too... but it's just much better in the long run to let them breath a bit before stomping on them. No matter what you might have heard/read... 41.7 is a STOUT load behind a 77gr.

For your edification, sharing velocities without barrel length does no one any good.

By the way, if you have the capability, video of that portion of your action through the bolt lift cycle would be even better.


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

Thanks for the input, it's a 20 inch barrel shooting suppressed. I got thae issue at hand even at 38 gr.
Thanks again.

 

[orkan]

Thanks for the input, it's a 20 inch barrel shooting suppressed. I got thae issue at hand even at 38 gr.
Thanks again.

Hence why I asked for the picture. I'm guessing you have a primary extraction timing issue. If the primary extraction cam isn't popping the case loose, then you'll need to yank the bolt hard to get it done.

Could be in the bolt handle root as pictured... could be in the head/head pin fitment area. Bottom line, if this is your issue, then a call to your smith or Zermatt will be in order and they'll need to get you fixed up with some parts/fitting. Sounds like you're confident it's not your chamber, so if that's the case, then it doesn't leave a whole lot of roads to go down for a potential cause here, if it's not brass/load/die related.

I assume it doesn't do it at all with unfired rounds? Can you cycle live rounds without the issue presenting itself? I assume you've tried single loading to rule out magazine/next round interference on the bolt? I assume you've got your lugs, primary extraction cam, bolt shroud to body interface, and cocking cam on the bolt body properly greased?

Just throwing some things out there for you to check.


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

 

[haisardao]

Yep, you are right, cycles perfect with unfired cases, no issues. Also, tried single loading, and even no mag in place, no change. And yes, they're greased. I'll send a picture later today. This is great input, I appreciate it.

 

[jonboatjockey]

My 22 Creed barrel from them had a tight neck, creating issues with pressure and brass (alpha). Make sure a bullet will slip into a fired case, easy to check and then go from there.

 

[orkan]

My 22 Creed barrel from them had a tight neck, creating issues with pressure and brass (alpha). Make sure a bullet will slip into a fired case, easy to check and then go from there.

Great advice. ^

If it's tight necked... you would still have pressure related problems down to the lowest functional charge.

I publicized my first ever 22 creed at .2575 with .080 freebore, and was neck turning 6.5 creed brass.

Now I have NO IDEA why the industry decided to anchor into that spec for the average shooter... but they did. That was back in like 2014 if memory serves.

The tightest neck a factory brass no-turn 22 creed should have is .260, and it should have at least .100 freebore.


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

 

[jonboatjockey]

Mine was really weird about pressure, sometimes I'd have it on lower charge weights, then it would go away as I moved up, then show back up. Not advised to ignore early pressure signs, I just was ignorant to them and bull headed. PBB opened mine up to .260, and no issued since. 88 ELDm's at 3150 in a 20" bbl.

 

[haisardao]

Man I'm glad I asked for help here. I'll update my findings shortly