The 22 creedmoor thread

[ID_Matt]

Settled on a load for now. N560 seems to be a good fit with the 88’s. Have an elk hunt in Wyoming this year and they don’t allow 22 cal’s so the 6 creed barrel is going back on soon. These tiny 22 cal holes sure make the groups look bigger than they are!! .76 moa over 10 shots works for me.

18” tikka tube with only 75 rounds.

 

[ACHILLES]

I'm using hornady brass as well, im on 9x firings. Primer pockets are starting to get pretty loose. If I want to stretch it out a little more, I throw a little bit of clear fingernail polish around the Primer after seating it. Definitely not recommending anyone do that, but it will get you a few more firings.

Nice and easy fix. I used to tighten pockets with a small ball bearing and a punch through the case. But I don’t mess with it anymore.

 

[waspocrew]

Sent 50 rounds down the barrel today with the 22 CM. A while back, Texas Ammunition sold 22 CM ammo (80 gr ELDM) and I'm wishing I would have bought more when I had the chance. Priced at $37/box, it was a good deal.

This is 20 rounds at 200 yards. Mirage was getting to be a little bit of a challenge in the heat, but pretty pleased with the results. White squares measure 2x2". Only chrono'd my last 5 rounds with Avg velocity of 3268, ES of 36.5.

 

[waspocrew]

Mead Ammo has factory ammo available as well - 77 and 85 gr versions. Loaded in Peterson LRP brass (with Mead headstamp). I picked up 5 boxes to try earlier this year when it was priced at $39/box. That's now gone up to $49/box unfortunately.

I only shot 20 rounds at 100 yards with the 77 gr Mead. Avg of 3192.5 and ES of 117 across the box of 20.

Accuracy was "ok", nothing stellar. Squares are 1". First 5 shot group on the left, then shot the middle 10 (which was a terrible 5 shot group to start so I kept going), then the last 5 shot group on the right. I'll have to shoot the 85 gr ammo next outing to see if it's any better.

 

[JRS3]

Care Package arrived today and I am excited to pop some caps!

 

[Stocky]

So when people send a dummy round what are they thinking for Coal with 88 elds. Ideally I want this rifle to be built around the 88s and have 2 final calls to make one is do I commit to throating for the 88 eld and run a coal around 2.75 to keep the bearing surface just above the neck-shoulder junction or do I run it a bit shorter to allow a backup option of running the 75s etc. I know small tweaks of jump don't usually make a huge difference but I can't imagine jumping say a 75 eld the extra 0.100" (difference in base to ogive for the 88 to 75) is going to help. I guess it's not a huge amount of jump.

Second question is do I commit to 7 twist or 8 twist. I'm in NZ so damn close to sea level in a few spots I hunt. 4dof shows the 88 going unstable around 20degrees at 3000fps. But potentially it's blowing bullets up with a 7 twist. There's not any commonly available 7 5 twist barrels here in NZ.

 

[id_jon]

I've concluded that if you're blowing up 88s in a 7 twist, you're over pressure anyway. I've blown up a few, but it was only when I was loaded hot, with a hot barrel, and it was 100 degrees F.

 

[Stocky]

I've concluded that if you're blowing up 88s in a 7 twist, you're over pressure anyway. I've blown up a few, but it was only when I was loaded hot, with a hot barrel, and it was 100 degrees F.

Wouldn't have thought blowing bullets had anything to do with pressure but velocity? Thought it was rpms that blow them.

 

[khuber84]

Wouldn't have thought blowing bullets had anything to do with pressure but velocity? Thought it was rpms that blow them.

You're correct. RPM and jacket pressure applied by the bore diameter. Once the bore condition starts to get a lil rough(which 22cm do) and apply that to high jacket pressure, jacket damage occurs, and high rpm will cause the bullet to go poof mid flight. The individual you replied to, well an 18" VS 26" barrel will likely have 200-250fps between them with the same load. So stating bullet failure is caused by excessive pressure is HIGHLY situational, and more of an exception and not a rule.

 

[HandgunHTR]

You're correct. RPM and jacket pressure applied by the bore diameter. Once the bore condition starts to get a lil rough(which 22cm do) and apply that to high jacket pressure, jacket damage occurs, and high rpm will cause the bullet to go poof mid flight. The individual you replied to, well an 18" VS 26" barrel will likely have 200-250fps between them with the same load. So stating bullet failure is caused by excessive pressure is HIGHLY situational, and more of an exception and not a rule.

I took the comment to state, "If you are blowing up bullets, you are at a velocity that is probably due to an overpressure situation."

 

[khuber84]

I took the comment to state, "If you are blowing up bullets, you are at a velocity that is probably due to an overpressure situation."

That statement is totally twist dependant. A 22cm has the ability to run stuff faster than most these bullets were designed to operate at muzzle velocity wise, especially at manufacturer suggested twist rated. Notice sierra states a 6.5tw is necessary for their 95tmk.

 

[id_jon]

I took the comment to state, "If you are blowing up bullets, you are at a velocity that is probably due to an overpressure situation."

That's what I was going for. In a 7 or 7.5 anyway.
Edit to add: particularly with shorter barrels, which I forget that not everyone shoots a 16" barrel still
If I were to shoot a 22-26" barrel I'd probably go with a 1:8

 

[Stocky]

That's what I was going for. In a 7 or 7.5 anyway.
Edit to add: particularly with shorter barrels, which I forget that not everyone shoots a 16" barrel still
If I were to shoot a 22-26" barrel I'd probably go with a 1:8

How fasts your 16 inch barrel throwing them? It's a 1 in 7 I take it?

 

[id_jon]

How fasts your 16 inch barrel throwing them? It's a 1 in 7 I take it?

2915. 2995 was blowing them up when it was hot, and getting pretty good ejector swipe. 4831sc

 

[khuber84]

Crazy thing I ran 75eldm with H4350 in an 18" 219 bore 7tw at 3250-3300 for a long time before it popped a few, around 800 rounds, throat was getting rough. Switched to tmk at 3100 and life was good till I pulled it at 1200 rounds. That 3300fps load was indeed on the spicey side.

 

[Gstew1930]

Crazy thing I ran 75eldm with H4350 in an 18" 219 bore 7tw at 3250 for a long time before it popped a few, around 800 rounds, throat was getting rough. Switched to tmk at 3100 and life was good till I pulled it at 1200 rounds. That 3300fps load was indeed on the spicey side.

Did you shoot anything with the TMK? I’ve got a load at 3300 now

 

[khuber84]

Did you shoot anything with the TMK? I’ve got a load at 3300 now

Coyotes mainly. I killed some deer/antelope with the 77tmk from my first 8tw 22cm, was a 22" running them at 3400. Results were very lethal, but do no put it on meat you plan to harvest, as it'll barely leave any left. For deer with that barrel I switched to 72? Gr absolute hammers with as much RL26 I could fit, they were running very fast, believe 3700 or something. Those killed very well too.

 

[Gstew1930]

Coyotes mainly. I killed some deer/antelope with the 77tmk from my first 8tw 22cm, was a 22" running them at 3400. Results were very lethal, but do no put it on meat you plan to harvest, as it'll barely leave any left.

That’s what I was worried about. I know it will kill. Figured there would be a lot of meat loss though

 

[eLightfoot]

I’ve shot a bunch of eldms 75s and 88s out of mine (7.5 t) none blow up. I’ve got a 26” barrel so they go fast. 4 out of 5 77grn TMKs will explode mid flight. It’s weird

 

[Stocky]

So when people send a dummy round what are they thinking for Coal with 88 elds. Ideally I want this rifle to be built around the 88s and have 2 final calls to make one is do I commit to throating for the 88 eld and run a coal around 2.75 to keep the bearing surface just above the neck-shoulder junction or do I run it a bit shorter to allow a backup option of running the 75s etc. I know small tweaks of jump don't usually make a huge difference but I can't imagine jumping say a 75 eld the extra 0.100" (difference in base to ogive for the 88 to 75) is going to help. I guess it's not a huge amount of jump.

Anyone regretted throating their barrel for 88s at a longer coal? Say around 2.75ish to keep the boat tail just above the shoulder-neck junction.