Reloading for Compass Lake SR Upper

[diddlehop]

I just received a Compass Lake Service Rifle Upper with a Douglas 7 twist barrel. It has been chambered with Compass Lakes own chambering, not a wylde chamber. They claim that their custom chambering is designed for the 80 SMK bullets. The first thing I noticed is that my reloads for a Rock River upper will not even chamber in the CLE upper. I use a Redding body die screwed down tight against the shell holder when raised so it wouldn't seem to be a headspace problem. This makes me think I need a small base die to reduce the case diameter near the base. I would appreciate any input from those with experience with CLE chambering.

Also, how much jump off the lands should I use with the 80 gr SMK's in this chamber?
thanks for your help.

 

[Bradley Walker]

I just received a Compass Lake Service Rifle Upper with a Douglas 7 twist barrel. It has been chambered with Compass Lakes own chambering, not a wylde chamber. They claim that their custom chambering is designed for the 80 SMK bullets. The first thing I noticed is that my reloads for a Rock River upper will not even chamber in the CLE upper. I use a Redding body die screwed down tight against the shell holder when raised so it wouldn't seem to be a headspace problem. This makes me think I need a small base die to reduce the case diameter near the base. I would appreciate any input from those with experience with CLE chambering.

Also, how much jump off the lands should I use with the 80 gr SMK's in this chamber?
thanks for your help.

You could be seated too long...

 

[diddlehop]

These are 69 SMK's seated to mag length that won't chamber.

 

[distinguished]

CLE chambers are cut to tighter dimensions than Wylde chambers. Get a small base sizing die. You may want to back your loads off about .5gr since the chamber is tighter. That will depend on what load you are currently using and if you see pressure signs. CLE is a quality upper, I went distinguished with an upper that had a CLE chambered barrel.

 

[diddlehop]

Thanks, good point about backing off the load. I will re-develop loads just for this barrel.

 

[KevinThomas]

I'm at Perry right now, and Frank and Theresa should be up here tomorrow. I'm sure I'll bump into them on the row. Be more than happy to ask them about this, and pass along anything they may have to offer. You've got me curious now, anyway.

 

[diddlehop]

Kevin,
Thanks for your offer. I knew they were headed for Camp Perry and was not able to get in touch with them at their business number. That's why I posted here.

Update; I picked up a RCBS small base die and tried resizing several cases . The cases will now chamber, most eject ok but I did have one stick. The one that stuck was Winchester headstamped. The others were all LC.

Just fyi, I measured some factory ammo for comparison, for Headspace I used the Hornady Headspace caliper kit.
PMC 223 - Diameter near Head .372, Headspace - 1.452
Military Green Tip ammo - Diameter - .373, Headspace - 1.452
Both of those chamber and eject with no problem.

Then I measured once fired Lake City 09 brass resized in the RCBS Small Base die;
Diameter - .373, Headspace 1.454

For reference, my Redding Body die gave these results:
Diameter- .374, Headspace - 1.456

Any case resized in the Redding Body die would not chamber. I don't think that the headspace was the issue because the bolt would not close enough for the headspace to be a factor. The bolt would have at least another 1/8" of travel to go before going into battery. This is why I believe it to be the case diameter that was stopping it from chambering.

How will headspace affect accuracy? I was told that the bolt on this new upper was Headspaced .001 over the go gauge. How much should the shoulder be bumped back from there for best accuracy and still allowing reliable chambering?

Thank you!

 

[Scott Harris]

Did you start with new brass in your new upper or try to reuse brass from another rifle? I've had issues using brass from another barrel. New brass solved my resizing problems and allowed me to use the standard Redding dies. I can't explain it, but them's the facts. As a side note, I've always run into problems with tight AR chambers. I personally don't think a tight AR chamber does a thing to help accuracy, but it sure impedes function. Wylde is the way to go IMHO

 

[diddlehop]

Scotharr, I'm using only previously fired brass.
I went to the range with the new upper today, but I had to use a LMT lower because the Rock River A2 lower it is destined for refuses to hold the bolt locked open. I even swapped the bolt catch from the LMT lower and put it into the Rock River lower. No joy, but the CLE upper works fine on the LMT lower with the Rock River bolt catch; what's up with that?

I was doing load development today and this upper was shooting about 5/8 MOA at 200 yards with some loads. I think it can do much better because my eyes were downright fuzzy today and I couldn't hold the gun still to save my life. (I slapped a scope on the upper for load development)

With all the hand loads sized with the small base die, none refused to chamber, none got stuck and all ejected just fine. I was using 77 SMK's today. Next will be Hornady 75 gr HPBT and 80 gr SMK.

 

[orsatime]

For the last 2 years I have struggled with figuring out how to load for the CLE chamber in a stainless Kreiger service rifle barrel. It is a great barrel and shoots sub MOA at 600 yds with SMK 80 projectiles. So for the benefit of those still pulling their hair out, I post the following:

1. You really can't use brass previously fired out of a generous chamber. If you do prepare for lots of heartache and frustration at the loading bench and the range. You have to size the hell out of the brass using a Dillon Carbide Die, and then check every single round for proper headspace. NATO brass fired out of my previous barrel that was chambered in Wylde is hit or miss for functionality in the CLE barrel. This leads to the next line item:​

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2. Get the CLE case gage they started providing. Each one has a number stamped on it which should not be exceeded when measuring from case head to the flat on the other end of the gage. Mine is 2.347". With calipers, check each round to ensure they are not too tall. Each round must fall into and out of the gage freely. If it sticks, you are risking failure to extract, ripped rims, extractor damage, and overall excessive stress on the BCG. All that mimics short-stroking/under-gassing or overgassing, if rims are being ripped. None of those are the real issue as I found out. It really was oversized brass for the CLE chamber that otherwise would be just fine in a Wylde chamber.​

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3. I have just fired a bunch of Winchester commercial brass that was sized with the aforementioned Dillon Carbide die and that worked great. That brass came from a source that fired this brass out of a test barrel with a tight chamber; however, just the same, I found that around 10% were very hard to size, but with case wax and care, I made them work. I normally use DIY lanolin/alcohol lube spray.​

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4. I believe the best bet is to start with NEW brass. Lucky for me, I have a enough. That's what's going to Perry with me this summer in 2022. I am wondering if my Redding S-die, Whidden bushing die or just what will size new 1X brass through the CLE chamber or if I will have to keep using the Dillon Carbide Die.​

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That's all, folks...comments welcome.​

 

[orsatime]

Did you start with new brass in your new upper or try to reuse brass from another rifle? I've had issues using brass from another barrel. New brass solved my resizing problems and allowed me to use the standard Redding dies. I can't explain it, but them's the facts. As a side note, I've always run into problems with tight AR chambers. I personally don't think a tight AR chamber does a thing to help accuracy, but it sure impedes function. Wylde is the way to go IMHO

ha ha...see my recent post on this matter

 

[Dusty Stevens]

I love my cle upper with krieger barrel. I use n135 and 75bthp. I use once fired LC brass ran thru an rcbs FL SB die and its perfect

 

[m1jeff]

I’ve run CLE chambers for 22 years now. I’ve used once fired military and range pick up brass with no problems. Been running Hornady New Dimension dies that entire time and never had a problem.

Get a Mo’s or Whidden case gauge and set headspace to zero. Go shoot a lot.

 

[fkimble@charter.net]

A ten year old thread bad from the dead! Like Jeff I've been shooting CLE barrels with the CLE chamberfor approx 20 years. Once fired LC and other range pickup brass once resized has no trouble functioning. I check a couple cases fire in each new barrel with my Mo's guage. Set my sizer die for 2-3 thou shoulder set back and rock and roll! One barrel did require me to sand down the top of my shellholder .001 when I switched to a different sizer die. But it was really a die problem.

Frank

 

[commander]

I have been thrashing a CLE chamber 1-7.7 Bartlein barrel all summer and have actually shot many groups in the 1s2s3s4s with Sierra Matchkings in 52-69-77 grain with Vitavouri and Varget powder using Redding bushing die and Lapua brass with 245-246-247 bushings and seating bullets with LE Wilson BR arbor micrometer seater die on 21ST century hydro press. All were loaded mag length approximately 2.26 in my mag. All rounds were shot off Sinclair light Benchrest at 100 yards. I have had 0 problems with this upper just bumping shoulder 1-2 thou and reloading. I also shot some Berger factory 77 OTM ammo and it shot in the 2s-3s. Thest CLE chambered uppers are just incredible if you feed them enough powder. They really like heavy loads. I have 750-800 rounds thru this one and it just keeps on shooting small groups. I usually shoot 30 rounds or so and put barrel cooler in barrel for 4-5 minutes and shoot on. Don’t burn up your barrel. KEEPEM SMALL. Mark