22 Creedmoor gas gun trials and tribulations

[Kocher]

Wanted to add 1-important finding that I found out later- ALWAYS, ALWAYS CHECK CHAMBER WITH GO/no go Guage!

My PrecisionAero HP bolt was out of spec and caused excessive head space! I will NEVER EVER EVER SHOOT A RIFLE AGAIN THAT IS NEW OR BUILD W/o checking this first!
Could that cause all the information below to be now voided? On a later date I will try again with a proper bolt!!!
———————-____________________________

wanted to give some information to save a lot of headaches for someone out there trying to use a Creedmoor 22 caliber and a AR 10 frame for use on small critters when using common bullets you’re in a 55 grn and 88 grn
Weights and give you my experience to help you know what to expect:

24 inch rainier barrel and had trouble reaching the high speeds the bolt guns reached.

With 4350 and other similar speed powders it would not get the speeds up for the lightweight bullets.
In fact at times I felt a 556 would’ve been just as fast.
With 41.5 grn 4150 and 55grain pill (tried many) = 3100fps

I played around with this for a long time and didn’t know what to do...
Should have posted on here...

Varget was the ticket= 40grn 3600fps+
This was 1st time I tried it.
41 gr too hot and did not help much with speed only 100fps.
I will continue to load it down just to see where the FPS goes is this the first time I tried it was just a couple days ago.

Varget may not work with 88ELD.
40grn Sw precision (varget copy).
ELD 88... Do not use way too hot Blew primer out and destroyed case.
I didn’t really have anywhere to start I don’t think I’ll ever try and do something like that again.

Posted some of the screenshots from the chronograph info but I hope this gives someone some help.


As far as anything to help with making the dwel timeincrease maybe +3 or+4 which they don’t make otherwise just use a heavy buffer tube, carbine length and a spring red from Springco A heavy duty spring carbine length.

I have tried everything else and it didn’t help not sure why manufactures would not try a longer tube for at least these overbore cartridges in the AR10 that may help!
All of the things don’t really matter.. or do anything to increasing speeds, or lessen cases damage while trying to increase dwell time ect.including the VTOL system.

It surprised me because I have a AR15 in the 17 Remington caliber and I did not run into any other issues that I ran into with a 22 CM in the AR10 chassis.

Hope that helps if anybody decides to take this on I’m probably gonna put it the barrel up for sale after my next hunt because I wanna be trying some different things.

 

[Kocher]

Ahh yes. I almost forgot..
When I went up one grain with the precision Sw. Varget copy. The 55grn SMK never made it to the target. It must have blown up!...

Reubenski: gas tube=+2. I think 3+ would have been ideal, but I am no expert.

I tried to run the gas block closed but the action still cycled.
I may shoot with gas’s block off and see what happens.

I’m not sure if the 88 ELD‘s are going that fast at 3000 ft./s but I think guys are able to push them further with the bolt guns.

 

[flyfisherman246]

Any issues with the long skinny bullets jamming into the feed ramps and not feeding? Did you happen to try any bergers for feeding?

 

[srt-4_uk]

As far as anything to help with making the dwel timeincrease maybe +3 or+4 which they don’t make otherwise just use a heavy buffer tube, carbine length and a spring red from Springco A heavy duty spring carbine length.

If you are running a +2, wouldn't going to a +3 or +4 decrease dwell time?

 

[TonyTheTiger]

If you are running a +2, wouldn't going to a +3 or +4 decrease dwell time?

From my reading here, less than 50% of people posting about dwell time understand dwell time.

 

[CaptArab]

40grn Sw precision (varget copy).
ELD 88... Do not use way too hot Blew primer out and destroyed case.
I didn’t really have anywhere to start I don’t think I’ll ever try and do something like that again.

Leeeeroooooooooy Jenkiiiiiinnnnnsssss

 

[CaptArab]

I am doing 3,000 feet per second with 75 ELDMs out of a 22 Grendel . . .

Bro you're my hero, what 22 cals DONT you shoot

 

[Kocher]

Any issues with the long skinny bullets jamming into the feed ramps and not feeding? Did you happen to try any bergers for feeding?

No issues.
Bergers fed just as good as the 55 Hornady, 55 SMK, 77 SMK, Hornady 88ELDs
I tried some 88.5 I believe. No issues.

 

[Kocher]

If you are running a +2, wouldn't going to a +3 or +4 decrease dwell time?

The Longer the Gas Tube, the increase in time it takes to push the gasses to the BCG and begin to unlock.

One could change the timing by cutting 2inches of barrel tip... this would let bullet out the barrel sooner and decrease chamber pressure.
Not sure how this would effect velocity?

I currently do not get any case damage, as they come out looking like they were , dare I say.. "shot out of a bolt gun"? as the charges are right up there...

I have run 77 SMK's @ 3200 w/o any case damage or pressure tails. so everything is working as it should.

 

[Kocher]

I will be trying the 55smk's and Varget copy powder, and No Gas Block... and see what speeds I reach, as even 3600 isn't all that great. when guys claim they reach 3800-3900! This is the only let down....
I will try other bullets with the SW precision powder. as it could just be the SMK's....

 

[srt-4_uk]

The Longer the Gas Tube, the increase in time it takes to push the gasses to the BCG and begin to unlock.

Idea is right but terminology is wrong. Dwell time is the amount of time the gas acts on the BCG. That happens when the bullet passes the gas port until it exits the muzzle

 

[iktomi]

People sometimes conflate "dwell time" with "bolt lock time"...

Post clearly referenced 'overbore'... so was referring to the timing as it related to pressure dropping (lock time).

 

[Kocher]

Idea is right but terminology is wrong. Dwell time is the amount of time the gas acts on the BCG. That happens when the bullet passes the gas port until it exits the muzzle

IMHO,
Longer the gas tube, less chance case is mangled from being pulled out prior to pressures dropping in chamber, and greater chance that the powder will be all burnt up prior to bullet exiting out in the barrel, this may increase FPS, and accuracy, assuming all else equal in the system. I am obviously, not adding that barrel length has an equal amount of importance to this relation.

Example. A rifle length gas tube on a 16 inch barrel may put the gas tube hole or port very close to the tip or end of the barrel, I could assume similar results if I cut 3 inches off the end of this 24 inch barrel.

 

[Kocher]

I appreciate all your guys input I would have to say that yes guns are quite a bit different than a bolt gun.

I am in no way an expert nor do I claim to be I’m sure there’s guys that I’ve been doing this for 40 some years maybe longer I do however enjoy what I’ve learned so far I hope I can pass that info on to others in a way that helps them.

 

[srt-4_uk]

People sometimes conflate "dwell time" with "bolt lock time"...

Post clearly referenced 'overbore'... so was referring to the timing as it related to pressure dropping (lock time).

People often conflate "tolerance" with "clearance." Word have meanings and it's important to know the difference.

While we are on the subject, that isn't what lock time is.

 

[Kocher]

Lol

 

[srt-4_uk]

Sorry, I thought the point of a technical forum was to share information.
How many times have people posted about their gun problems only to be lead in the wrong direction because they described it wrong? Just trying to fix that.

 

[Kocher]

I am interested in if guys have used a lightweight bcg successfully in the Ar10 platform and what calibers work with it

 

[Kocher]

Sorry, I thought the point of a technical forum was to share information.
How many times have people posted about their gun problems only to be lead in the wrong direction because they described it wrong? Just trying to fix that.

We are all humans, and the more we know about the tools available to us the better... I would not sweat about responses

 

[srt-4_uk]

I am interested in if guys have used a lightweight bcg successfully in the Ar10 platform and what calibers work with it

I've used a JP LOMS with a 16" 308 that lives suppressed. Gas turned wayyyyy down.

 

[buggz]

Any reason to pick this cartridge over 224 Valkyrie?
Just asking, as I am considering a 224 Valkyrie upper.

 

[Kocher]

I thought maybe there was someone else that made a 22 Creedmoor and tried with a lightweight BCG and what was the results?

When first starting this project I did not have a chronograph and I only had big game &H380 on my table. No one used those powders and I was overloading things.


My 6.5 CM build has gotten “lite side” of thinking though ..

Call the obvious?

 

[Kocher]

Any reason to pick this cartridge over 224 Valkyrie?
Just asking, as I am considering a 224 Valkyrie upper.

New 22 cal for varmints - What to chamber 22-250, 22-250AI, 22GT, 22 Creed?

Time for a new 22 cal barrel on my Impact action for varmints. Previously ran a standard 22-250 with 50-65 grn pills with a 1:12 twist tube. Worked well for coyotes up to 400 yards and p-dogs to 600. I am toying with the idea of heavier bullets (70-90 grn) this time around to stretch my...

www.snipershide.com

It explores the topic... guys say that Hornady tops out 88eld @2700

 

[Kocher]

Looking at some stats...55grn @ 3600 is 22-250 speeds so tech. mission accomplished as the entire mission of this build was to :

make a 22-250 speeds/rounds work in a meg fed gas gun= mission accomplished.

couple 200 fps on the table... yep.
Right now though:

Cases come out looking like been out of a bolt gun.

lots of flex to run any 22 cal pill

Parent cases plenty, and many options to go to 6CM, or 6.5CM (I have both so not worries about needing /using cases.

 

[Zback]

I thought maybe there was someone else that made a 22 Creedmoor and tried with a lightweight BCG and what was the results?

When first starting this project I did not have a chronograph and I only had big game &H380 on my table. No one used those powders and I was overloading things.


My 6.5 CM build has gotten “lite side” of thinking though ..

Call the obvious?

I had a custom 22 creed built on AR 10 platform by DNA Firearms and it is flawless.

 

[Kocher]

I had a custom 22 creed built on AR 10 platform by DNA Firearms and it is flawless.

That sounds great did you ever get a chance to see what velocities and with different bullets?

Gas block length barrel length things like that?

Thank you for the reply

 

[padom]

I can imagine 22 Creedmoor in an AR would be pretty troublesome. What is your gas tube length and port size?

I am doing 3,000 feet per second with 75 ELDMs out of a 22 Grendel in an AR15 platform. 22-in barrel suppressed.

I would think 22 GT might do a little better in an AR-10. Maybe try to slow ball powder like sta ball or h414. I would also use an adjustable gas block and turn the gas off and see what my top end pressures were with that.

I think you're also in the territory with 55 grain bullets out of a 22 Creed that you definitely need the right barrel twist for it. The harder you spin bullets in a barrel the more pressure is increased. Much less the issue of turning them apart

I actually have a blank and parts sitting here to build a 22BR or 22GT upper for my MEGA LR-308 gasser to go with my .308 and 6.5cm uppers.... Just havent got around to that project been super busy these past 8 months. Maybe the next month or two Ill get it together and start testing..

 

[232593]

Looking at some stats...55grn @ 3600 is 22-250 speeds so tech. mission accomplished as the entire mission of this build was to :

make a 22-250 speeds/rounds work in a meg fed gas gun= mission accomplished.

couple 200 fps on the table... yep.
Right now though:

Cases come out looking like been out of a bolt gun.

lots of flex to run any 22 cal pill

Parent cases plenty, and many options to go to 6CM, or 6.5CM (I have both so not worries about needing /using cases.

How did your 22CM work out? Are you still getting the same results? Have you tried any of the 90 grain bullets?

 

[Kocher]

I had put the upper away and had been shooting some 6.5 in the ar10
Powder choice is everything.
The twist is quite fast for a 53-55grain ballistic tip varmint. so when pushed to 3800+ the pulled falls apart.
Will try some other heavier bullets in the future, but I believe a better twist would be like 8-10 or ever a 1/12. for varmint bullets.

I wanted a semi auto- varmint rifle, and may in the future spin up a slower twist barrel and give it a wirl.

I have been running a 17rem ar15 as of late that is balls accurate and runs perfectly with a bolt gun.

I have built a 22cm bolt gun and with out realizing I got a fast twist...barrel... ooops. so I will see but
IMHO, a slow twist 22CM AR10 with some appropriate fast burning powder can run very well with very fast speeds, and would be perfect for high volume LONG rang varmint rifle.

 

[232593]

I had put the upper away and had been shooting some 6.5 in the ar10
Powder choice is everything.
The twist is quite fast for a 53-55grain ballistic tip varmint. so when pushed to 3800+ the pulled falls apart.
Will try some other heavier bullets in the future, but I believe a better twist would be like 8-10 or ever a 1/12. for varmint bullets.

I wanted a semi auto- varmint rifle, and may in the future spin up a slower twist barrel and give it a wirl.

I have been running a 17rem ar15 as of late that is balls accurate and runs perfectly with a bolt gun.

I have built a 22cm bolt gun and with out realizing I got a fast twist...barrel... ooops. so I will see but
IMHO, a slow twist 22CM AR10 with some appropriate fast burning powder can run very well with very fast speeds, and would be perfect for high volume LONG rang varmint rifle.

I was planning on running the 77 & 90 grain bullets.

Did your brass ever get beaten up with the load bullet combo you used?

 

[Kocher]

The brass would only get jacked up if it was over saami MAX specs. I could not get the speed out of 55 grain pill and H4350 (substituted with IMR 4350) claimed was 3800 FPS and I believe due to the fast twist 1/6 was rippn up the bullets. even so the cases were fine.
I had even shut the gas block completely and saw no change in FPS.

Otherwise , the gun ran flawless. I will revisit it again.

 

[232593]

The brass would only get jacked up if it was over saami MAX specs. I could not get the speed out of 55 grain pill and H4350 (substituted with IMR 4350) claimed was 3800 FPS and I believe due to the fast twist 1/6 was rippn up the bullets. even so the cases were fine.
I had even shut the gas block completely and saw no change in FPS.

Otherwise , the gun ran FLALESS. I will revisit it again.

What length of barrel did you put on it and who made the upper?

 

[Kocher]

What length of barrel did you put on it and who made the upper?

Barrel = 24 inch rainier barrel. They don't make any in the 22 CM anymore.. It was a limited run.
It was under 1MOA and would go better with heavier bullets, as I mainly
1/6 twist, just didn't try many of the 77 gr+
Used basic off the shelf parts.
Aero Precision upper/lower and BCG.
Trued Upper with Lapper and assembled it.
All in all it ran great. I took a break from it all and was good to sit back look at it and realize that all it all it went well.

Powder and twist having the greatest impact with this caliber (22 CM)

 

[232593]

I actually have a blank and parts sitting here to build a 22BR or 22GT upper for my MEGA LR-308 gasser to go with my .308 and 6.5cm uppers.... Just havent got around to that project been super busy these past 8 months. Maybe the next month or two Ill get it together and start testing..

Were you able to build it?

 

[232593]

The brass would only get jacked up if it was over saami MAX specs. I could not get the speed out of 55 grain pill and H4350 (substituted with IMR 4350) claimed was 3800 FPS and I believe due to the fast twist 1/6 was rippn up the bullets. even so the cases were fine.
I had even shut the gas block completely and saw no change in FPS.

Otherwise , the gun ran flawless. I will revisit it again.

My 22 CM upper should be sent out this week. It has a +3 gas system, AGB, and a Bartlein barrel on it. For break in I have some Copper Creek Cartridge Hornady 75, 88, and 90 grain rounds in Peterson Brass. I have H4350, STABAL HD, and Retumbo. Still looking for RL26.

 

[232593]

Just standard AR10 magazines right?

 

[232593]

Tested mine this weekend with Copper Creek factory ammo loaded with 75, 88, and 90 grain bullets. No cycling issues but I was not running full mags due to doing barrel break in.

From what I have seen so far my 26” barrel seems to like the 90 grain ATIPS best. They grouped between .5-.75” with a MV of 2960 or so. Brass looked pretty good for ejecting at the 3 o’clock position with the superlative arms AGB.

Only issue I have is the bolt does not lock back when ejecting at the 4 o’clock position.

I only have about 20 rounds through the barrel.

 

[232593]

Has anyone tried Vihtavouri powders in 22 Creedmoor? Or Aliant (besides RL26)?

 

[232593]

No issues.
Bergers fed just as good as the 55 Hornady, 55 SMK, 77 SMK, Hornady 88ELDs
I tried some 88.5 I believe. No issues.

What kind of magazines did you use?

With Magpul Pmags 88 & 90 grain bullets get damage to the tip of the bullet. I’m told the LaRue .308 mags fix the problem, any truth to that?

 

[232593]

LaRue mags fixed the issue with the tips of ALCO 90 gains being damaged. Problem is that when I charge the weapon and eject the round the CBTOL is increasing by .010 despite .004 neck tension. And at velocities above 3060 I’m blowing up bullets.

Hopefully the Lee crimp die can alleviate the CBTOL increase some?

 

[mettee]

LaRue mags fixed the issue with the tips of ALCO 90 gains being damaged. Problem is that when I charge the weapon and eject the round the CBTOL is increasing by .010 despite .004 neck tension. And at velocities above 3060 I’m blowing up bullets.

Hopefully the Lee crimp die can alleviate the CBTOL increase some?

What are your brass specs, brand, etc? Are you annealing? What is the thickness of the brass at the neck?

Can't believe your bullet is coming out like that...

What weight is your bcg and buffer, and what recoil system are you running?

 

[232593]

What are your brass specs, brand, etc? Are you annealing? What is the thickness of the brass at the neck?

Can't believe your bullet is coming out like that...

What weight is your bcg and buffer, and what recoil system are you running?

I do anneal but this is new Alpha and Peterson brass that I’m using. The phenomenon is even worse with the Peterson brass. Bullet jumps .020-.030. With Alpha brass it jumps .004”. I don’t have neck thickness measurements with me at the moment.

I’m running a standard AR10 Aero buffer and spring. I have one of the heavy buffers and springs on hand. Wouldn’t the extra mass of that heavy buffer make things worse?

 

[mettee]

Your brass is really good, I don't think that is the issue.

What is your reciprocating mass? and what spring?

 

[232593]

Your brass is really good, I don't think that is the issue.

What is your reciprocating mass? and what spring?

I have a standard MILSPEC BCG and a standard Aero Precision buffer and spring. I have not weighed the BCG yet.

Would modifying the mass of the BCG help?