Precision Delta 124 OAL 9 Major

[pewpewpew03]

I picked up a CK Thunder with the kkm barrel over black Friday and I'm working up a load with AA7.  Im finding out that the max OAL is 1.145 during a plunk and spin test.  Crimp is .376.  searching the forums here I've seen quite a few posts about their OAL being 1.165 with the PD124s in 9 major. 

Do I work up a load with the 1.145 OAL and send it? or should I send this barrel off to be reamed to be able to accept the 1.165?

[muncie21]

Have you thought about trying a different profile/weight bullet?  If that's all you have, what's the harm in loading a few up and running them across a chrono.

[pewpewpew03]

2 minutes ago, muncie21 said:

Have you thought about trying a different profile/weight bullet?  If that's all you have, what's the harm in loading a few up and running them across a chrono.

This is my second profile/try....my first was coated lead that i had laying around from minor and that was like a shotgun grouping and too many variances in oal, ogive etc so now I'm trying the 124PD that I've seen as a very popular projectile.   This is one of my few mock-up OAL rounds.  doesn't look like it would compress the load.  i could start at like 9.0 and work my way up and see what happens over the chrono this weekend.

[NoSteel]

I run the same barrel at 1.155 with 124 PD HP and could easily go longer.  I would finish ream it to get your OAL out to 1.16".  It just gives you a little more leeway to taylor your load. I run 6.9gr WAC to make ~175pf, 2 popple holes...

 

Just seeing your added pic..  Looks like you need more crimp?

Edited December 19, 2018 by NoSteel

[pewpewpew03]

8 minutes ago, NoSteel said:

Looks like you need more crimp?

 

it measures out to 0.376...might look weird in the pic... i made 10 oal dummy rounds...all measure with in 002 oal all plunk and spin with the crimp at 376

 

[NoSteel]

5 minutes ago, pewpewpew03 said:

it measures out to 0.376...might look weird in the pic... i made 10 oal dummy rounds...all measure with in 002 oal all plunk and spin with the crimp at 376

 

Have you pulled a bullet to see what it looks like??  I also am .374/5 but get a little coke bottling because I use a U-die sizer..  As stated above,  you can load up and run fine at the 1.145..  Just listing options for you...

[Hi-Power Jack]

30 minutes ago, NoSteel said:

 

Just seeing your added pic..  Looks like you need more crimp?

 

The left side of the photo looks like you need more crimp - the right side, up against

the bullet, doesn't - hard to tell.

 

The PD profile is very similar (If not identical), from my experience, to the MG 124

gr JHP - kind of a standard shape 124.   The RMR is different.

 

I have run MG 124's to 1.145", with WAC and HS6, but not sure you'd get AA7

in there and stay at 1.145".

 

Lot safer to have the throat reamed a bit and load longer, esp. with AA7.     

[hamiltonian]

I am a fan of freebore so you can load to a variety of OAL and determine whatever length feeds best and lowers pressures.  Send your  barrel to a gunsmith that can freebore.  It usually costs less than $50.  It have never noticed any decrease in accuracy, either.

Edited December 19, 2018 by hamiltonian

[Jfitz427]

I’ve read a few accounts that some CKs sometimes come short chambered. I would get it reamed a bit more, atleast so you can load out to 1.160-1.170. Although, from what I’ve heard checmates have pretty short throats and people load short like that without issue. So, maybe work up some loads. Although overall these guns seem to run a bit better with longer loads. You’ll just have to experiment. It’s pretty cheap to have it reamed, gans charges 50 bucks. And you won’t have to send your whole gun, which costs a lot due to the insurance, just the barrel. 

Edited December 19, 2018 by Jfitz427

[36873687]

Send it to Bobby. I sent  barrel in just paid shipping to am from. Have him ream the Comp also.have no idea why they don’t do this during the build

[36873687]

We are about the same on powder an ovl an Bullets I’m using 115 now but aa7 is sweet in both my ck. I had a bunch loaded when I picked up second ck an was bummed first trip to the range an the plunk test. But ck made it right. Think I had $25 in shipping 

[jnr88]

Good advice on the comp. I use PD at 1.165 in 3 guns. That will give you the flexibility to use different powders

[chevrofreak]

I run PD 124's and 115's at 1.145" in my CK.

[Hi-Power Jack]

4 hours ago, chevrofreak said:

I run PD 124's and 115's at 1.145" in my CK.

 

Are you using a fast powder (WAC or HS6) or are you using a slower

powder (AA7, etc ?)   

 

I've loaded WAC and HS6 to 1.145" but not sure you can get 9 - 10

gr of AA7 into the case at 1.145" - might need to load out to 1.165"

with the larger volume of powder  ???

[chevrofreak]

6 hours ago, Hi-Power Jack said:

 

Are you using a fast powder (WAC or HS6) or are you using a slower

powder (AA7, etc ?)   

 

I've loaded WAC and HS6 to 1.145" but not sure you can get 9 - 10

gr of AA7 into the case at 1.145" - might need to load out to 1.165"

with the larger volume of powder  ???

7.8gr of HS6, 8.8gr of 3N38 of 7.7gr of Silhouette at those lengths with a 124.  8.6gr of HS6, 9.4gr 3N38 or 8.3gr Silhouette with a 115 at the same length.   I have used AA7, but never with anything but an Everglades V2, using 10.5gr at 1.165"

Edited December 19, 2018 by chevrofreak