AI AXMC 22 Creedmoor

[Raven81]

Anyone shooting 22 CM in AI AXMC? I had a 20” barrel spun by SAC, and ran some Copper Creek (Alpha Brass) 88 ELDMs in it this weekend and fired rounds are sticking in the ejector. Anyone else had this issue? Barrel shoots great, but rounds wont eject off the bolt.

 

[AIAW]

Have you tried other calibers with that same bolt face (308, etc)?

 

[diderr]

What kind accuracy are you getting? I was looking at eventually putting a 22cm together

 

[EXSOCAL]

My barrel will be done this week, I can PM you after I shoot it.

 

[ingraham]

I tried a H4350 with the Berger 80.5 bullets, the same as I'm shooting in 22x47L. The 22 CM seems to like 3 grains more powder than the 22x47L and is shooting 200 fps faster but it also has 2" extra barrel.

 

[redneckbmxer24]

Post pics of the case heads of a few cases, specifically ones that got stuck.

 

[Raven81]

Here’s a quick viideo showing the issue...

 

[ironsight1000yard]

Video took more than 12 mins to load

 

[Raven81]

Well looks like the video wont load up...so back to the drawing board.

The problem is the 22 CM Alpha brass is hanging up under the extractor, and Hornady 6.5 CM or 308 brass doesn’t.

As far as accuracy, looks great so far, but only fired 7 rounds as I was frustrated with the malfunction on every round. But lowest velocity was 3082 and highest 3111 and less than 1/2 MOA at 100 yards. So not bad with 20” tube. I’ve also got 100 80 ELDMs to try, but they seem to have the same problem.

 

[Raven81]

Here’s a pic...Alpha fired 22 CM left, unfired middle, Hornady 6.5 CM right for comparison

 

[Raven81]

Also just noticed the strange ring at the base of all the fired 22 CM brass....hmmm. Might need to put a go-no-go gauge on this SAC barrel?

 

[AIAW]

Sounds like the Alpha rims might be out of spec if your Hornady brass runs fine.

Did you end up with some burrs on the rim of the brass that didn't eject?

Is it just me or does your fired piece look way bigger!?

 

[Raven81]

When you run your finger across the rim of the fired brass, yes, you can feel some nicks from forcing them out from under the extractor.

 

[Raven81]

Im gonna disassemble the bolt at the local shop and see if something got underneath the extractor tomorrow

 

[AIAW]

Probably not a bad idea. Might just need to check the extractor for burrs itself.

If you could, can you measure the difference in diameter on that fired brass versus the unfired piece right above where that ring is near the web?

 

[DAVETOOLEY]

Just a guess but compare rim thickness. Does it cycle new unfired brass?

 

[Raven81]

@ Dave...the Hornady and the Aplha rims mic about the same, although the Alpha certainly has much sharper edges

And, we’ve discovered a crack in my bolt body near the extractor, so the whole rifle (SAC barrel), and some Copper Creek ammo is going to AINA, and we’ll see what they say.